DRAFT SYSTEM

TECHNICAL REQUIREMENTS DOCUMENT

APPENDIX D

NATIONAL POLAR-ORBITING OPERATIONAL ENVIRONMENTAL SATELLITE SYSTEM (NPOESS)

PROGRAM DEFINITION AND RISK REDUCTION PROGRAM

17 March 1997

40.1 Conventions/General EDR Requirements 140.1.1 Requirements Format 140.1.2 Key EDRs/Attributes 140.1.3 Attribute Values 140.1.4 Attribute Values Expressed as Percentages 140.1.5 Vertical Height 140.1.6 Specification of Attributes at Nadir 140.1.7 Impact of Weather Conditions on EDR Requirements 240.2 Key EDRs 240.2.1 *Atmospheric Vertical Moisture Profile 240.2.2 *Atmospheric Vertical Temperature Profile 440.2.3 *Imagery 540.2.3.1 Explicit EDR Requirements 540.2.3.2 Application-Related Requirements (TBR) 640.2.3.2.1 Manually Generated Cloud Data 640.2.3.2.1.1 Cloud Cover 740.2.3.2.1.2 Cloud Type 740.2.3.2.2 Sea Ice Data 840.2.3.2.2.1 Ice Edge Location 940.2.3.2.2.2 Ice Concentration 940.2.4 *Sea Surface Temperature (SST) 1040.2.5 *Sea Surface Winds (Speed and Direction) 1140.2.6 *Soil Moisture 1240.3 Atmospheric EDRs 1240.3.1 Aerosols 1240.3.1.1 Aerosol Optical Thickness 1340.3.1.2 Aerosol Particle Size Parameter 1440.3.1.3 Suspended Matter 1540.3.2 Ozone Total Column/Profile (DOC) 1540.3.3 Precipitable Water 1740.3.4 Precipitation (Type, Rate) 1740.3.5 Pressure Profile (TBR) 1840.3.6 Total Water Content 1940.4 Cloud EDRs 1940.4.1 Cloud Base Height 1940.4.2 Cloud Cover/Layers 2040.4.3 Cloud Effective Particle Size 2040.4.4 Cloud Ice Water Path (DOC) 2140.4.5 Cloud Liquid Water 2140.4.6 Cloud Optical Thickness (IORD Name: Cloud Optical Depth/Transmissivity) 2240.4.7 Cloud Top Height 2240.4.8 Cloud Top Pressure (DOC) 2340.4.9 Cloud Top Temperature 2440.5 Earth Radiation Budget EDRs 2440.5.1 Absorbed Solar Radiation (IORD Name: Net Shortwave Radiation) (DOC) 2540.5.2 Albedo (Surface) 2540.5.3 Downward Longwave Radiation (Surface) (DOC) 2640.5.4 Downward Shortwave Radiation (Surface) (IORD Name: Insolation) (DOC) 2640.5.5 Outgoing Longwave Radiation (Top of Atmosphere) (IORD Name: Total Longwave Radiation) (DOC) 2840.5.6 Solar Irradiance (DOC) 2840.6 Land EDRs 2940.6.1 Land Surface Temperature 2940.6.2 Normalized Difference Vegetation Index (NDVI) (TBR) 2940.6.3 Snow Cover/Depth 3040.6.4 Vegetation Index/Surface Type 3140.7 Ocean/Water EDRs 3240.7.1 Currents (DoD-coastal; DOC-surface) 3240.7.2 Fresh Water Ice 3340.7.3 Ice Surface Temperature 3440.7.4 Littoral Sediment Transport 3440.7.5 Net Heat Flux 3540.7.6 Ocean Color/Chlorophyll 3540.7.7 Ocean Wave Characteristics (TBR) 3640.7.8 Sea Ice Age and Sea Ice Edge Motion 3740.7.9 Sea Surface Height 3740.7.10 Surface Wind Stress (DOC) (TBR) 3840.7.11 Mass Loading (TBR) (IORD Title - Turbidity) 3840.8 Space Environmental EDRs (TBR) 3940.8.1 Auroral Boundary 3940.8.2 Total Auroral Energy Deposition 3940.8.3 Auroral Imagery 4040.8.4 Electric Fields 4040.8.5 Electron Density Profiles/Ionospheric Specification 4140.8.6 Geomagnetic Field 4240.8.7 In-situ Ion Drift Velocity 4240.8.8 In-situ Plasma Density 4340.8.9 In-situ Plasma Fluctuations 4340.8.10 In-situ Plasma Temperatures 4440.8.11 Ionospheric Scintillation 4440.8.12 Neutral Density Profiles/Neutral Atmospheric Specification 4540.8.13 Radiation Belt/Low Energy Solar Particles 4640.8.14 Solar/Galactic Cosmic Rays 4740.8.15 Solar Extreme Ultraviolet Flux 4740.8.16 Supra-Thermal through Auroral Particles 4840.8.17 Upper Atmospheric Airglow (TBR) 4940.9 Notes on Space Enviromental EDRs 5040.9.1 Auroral Boundary 5040.9.2 Total Auroral Energy Deposition 5040.9.3 Auroral Imagery 5040.9.4 Electric Fields 5040.9.5 Electron Density Profiles/Ionospheric Specification 5140.9.6 Geomagnetic Field 5140.9.7 In-situ Ion Drift Velocity 5140.9.8 In-situ Plasma Density 5140.9.9 In-situ Plasma Fluctuations 5140.9.10 In-situ Plasma Temperatures 5140.9.11 Ionospheric Scintillation 5140.9.12 Neutral Density Profiles/Neutral Atmospheric Specification 5140.9.13 Radiation Belt/Low Energy Solar Particles 5140.9.14 Solar/Galactic Cosmic Rays 5240.9.15 Solar Extreme Ultraviolet Flux 5240.9.16 Supra-Thermal through Auroral Particles. 5240.9.17 Upper Atmospheric Airglow (TBR) 5240.1 Conventions/General EDR Requirements

40.1.1 Requirements Format

EDR requirements are specified by a general definition of the required data content, the units for the reported data, and a set of attributes. These attributes fall into four categories: (1) those that further define data content in a precise, quantitative manner, (2) those that constrain the quality of the data to be provided, (3) those that constrain the reporting frequency for the EDR, and (4) the timeliness of EDR delivery to users. The attributes addressing data content are horizontal and vertical cell size, horizontal and vertical reporting interval, and horizontal and vertical coverage. The attributes addressing data quality are measurement uncertainty, measurement accuracy, measurement precision, long term stability, and mapping uncertainty. The primary attributes addressing reporting frequency are maximum local average revisit time and maximum local refresh.. All of these attributes apply to data products, not to sensor performance characteristics, and are defined in the Glossary. The EDR requirements format is to address the data content attributes first, then the data quality attributes, and finally the reporting frequency attributes. The timeliness requirement is the same for all EDRs, and is specified as a global requirement in the "Data Availability" section (Sec. 3.2.1.2).

General EDR requirements fall into two classes: (a) explicit requirements on the EDR content, quality, refresh, and timeliness, and (b) requirements to be derived by the contractor based on requirements for other EDRs. The explicit and application-related requirements are specified below.

TRD40.1.1-1

If a derived requirement conflicts with an explicit requirement and/or another derived requirement, the most stringent requirement shall be satisfied.

40.1.2 Key EDRs/Attributes

Attributes marked with an asterisk are key attributes. A key EDR is one for which at least one attribute is key. Key EDRs are marked with an asterisk. Key attribute names and values are also in bold font. Compliance with the TRD requires satisfaction of all EDR thresholds, whether the attribute or its EDR is key or not.

40.1.3 Attribute Values

Unless otherwise specified, attribute values are to be interpreted as upper bounds anywhere in the area where measurements are obtained, including the edge of the measuring sensor field of regard. A threshold or objective is "met" or "satisfied" if the system performance value is less than or equal to the specified value.

40.1.4 Attribute Values Expressed as Percentages

Unless otherwise specified, a percentage appearing as a value for an attribute is to be interpreted as the percentage of the true value of the attribute. For any attribute where a percentage and a numerical value are specified, the greater of the two is the requirement.

40.1.5 Vertical Height

Vertical height is measured either by atmospheric pressure or by height above the earth's surface. A value of zero km for height refers to the earth's surface. Negative values of height refer to depth below the earth's surface (land or water).

40.1.6 Specification of Attributes at Nadir

Specification of horizontal cell size or horizontal spatial resolution at nadir does not imply that data must be acquired from a cross-track scanning sensor. The data may be acquired from a conically scanning sensor or any other sensor as long as the horizontal cell size or resolution along the satellite ground track does not exceed the nadir upper bound. For an EDR for which horizontal cell size is specified only at nadir, cell size is allowed to grow away from nadir as a normal function of the look angle.

40.1.7 Impact of Weather Conditions on EDR Requirements

The requirements for "clear" conditions are more stringent and apply when atmospheric conditions are such that infrared sensing (or any comparably capable technology) can be applied. The requirements for "cloudy" conditions are less stringent and apply when atmospheric conditions preclude the use of infrared sensing (or any comparably capable technology), but which can be met by microwave sensing (or any comparably capable technology). For guidance purposes, the government recommends that "clear" refer to less than 50 % cloud cover and "cloudy" refer to greater than or equal to 50 % cloud cover. Except for cloud EDRs and Space Environment EDRs, which must be met regardless of cloud cover, specification of whether an EDR must be met under clear and/or cloudy conditions is provided for each EDR.

TRD40.1.7-1

The contractor shall specify the conditions under which the requirement to deliver an EDR meeting data content and quality requirements will not be met, regardless of whether it is clear or cloudy.

TRD40.1.7-2

The contractor shall also specify the conditions under which it would recommend delivering an EDR which is incomplete and/or of degraded quality but which is still of potential utility to one or more users.

40.2 Key EDRs

40.2.1 *Atmospheric Vertical Moisture Profile

An atmospheric vertical moisture profile is a set of estimates of average mixing ratio in three-dimensional cells centered on specified points along a local vertical. For this EDR, horizontal cell size is specified at nadir only. The mixing ratio of a sample of air is the ratio of the mass of water vapor in the sample to the mass of dry air in the sample.

Units: g/kg


Para.                                     Thresholds      Objectives      
No.                                                                       

40.2.1-1  a.  Horizontal Cell Size        15 km @ nadir   2 km @ nadir    

40.2.1-2  b.  Horizontal Reporting         (TBD)           (TBD)          
          Interval                                                        

40.2.1-3  c.  Vertical Cell Size          2 km            2 km            

          d.  Vertical Reporting                                          
          Interval                                                        

40.2.1-4   1. surface to 850 mb           20 mb           5 mb            

40.2.1-5   2. 850 mb to 100 mb            50 mb           15 mb           

40.2.1-6  e.  Horizontal Coverage         Global          Global          

40.2.1-7  f.  Vertical Coverage           Surface to 100  Surface to 100  
                                          mb              mb              

40.2.1-8  g.  Measurement Range           0 - 30 g/kg     0 - 30 g/km     

          h.  *Measurement Uncertainy                     10 %/ 2 km      
          (expressed as a percent of                      layers          
          average mixing ratio in 2 km                                    
          layers)                                                         

           Clear                                                          

40.2.1-9   1. *surface to 600 mb          20%  or         10%             
                                          0.2g/kg (TBR)                   

40.2.1-10  2. 600 mb to 300 mb            35% or 0.1g/kg  10%             
                                          (TBR)                           

40.2.1-11  3. 300 mb to 100 mb            35% or 0.1g/kg  10%             
                                          (TBR)                           

           Cloudy (TBR)                                                   

40.2.1-12  4. *surface to 600 mb          20% or 0.2g/kg  10%             
                                          (TBR)                           

40.2.1-13  5. 600 mb to 300 mb            40% or 0.1g/kg  10%             
                                          (TBR)                           

40.2.1-14  6. 300 mb to 100 mb            40% or 0.1g/kg  10%             
                                          (TBR)                           

40.2.1-15 i.  Mapping Uncertainty         5 km            1 km            

40.2.1-16 j.  Maximum Local Average       6 hrs           3 hrs           
          Revisit Time                                                    

40.2.1-17 k.  Maximum Local Refresh         (TBD)          (TBD)          



40.2.2 *Atmospheric Vertical Temperature Profile

An atmospheric temperature profile is a set of estimates of the average atmospheric temperature in three-dimensional cells centered on specified points along a local vertical.

Units: K


Para.                                     Thresholds      Objectives      
No.                                                                       

          a. Horizontal Cell Size                                         

40.2.2-1   1. Clear, nadir                18.5 km         5 km            

40.2.2-2   2. Clear, worst case           100 km          (TBD)           

40.2.2-3   3. Cloudy, nadir               40 km           5 km            

40.2.2-4   4. Cloudy, worst case          50 km           (TBD)           

40.2.2-5  b.  Horizontal Reporting         (TBD)           (TBD)          
          Interval                                                        

          c.  Vertical Cell Size                                          

           Clear                                                          

40.2.2-6   1. surface to 300 mb           1 km            (TBD)           

40.2.2-7   2. 300 mb to 30 mb             3 km            (TBD)           

40.2.2-8   3. 30 mb to 1 mb               5 km            (TBD)           

40.2.2-9   4. 1 mb to 0.01 mb             5 km            (TBD)           

           Cloudy                                                         

40.2.2-10  5. surface to 700 mb           1 km            (TBD)           

40.2.2-11  6. 700 mb to 300mb             1 km            (TBD)           

40.2.2-12  7. 300 mb to 30 mb             3 km            (TBD)           

40.2.2-13  8. 30 mb to 1 mb               5 km            (TBD)           

40.2.2-14  9. 1 mb to 0.01 mb             5 km            (TBD)           

          d.  Vertical Reporting                                          
          Interval                                                        

40.2.2-15  1. surface to 850 mb           20 mb           15 mb           

40.2.2-16  2. 850 mb to 300 mb            50 mb           15 mb           

40.2.2-17  3. 300 mb to 100 mb            25 mb           15 mb           

40.2.2-18  4. 100 mb to 10 mb             20 mb           10 mb           

40.2.2-19  5. 10 mb to 1 mb               2 mb            1 mb            

40.2.2-20  6. 1 mb to 0.1 mb              0.2 mb          0.1 mb          

40.2.2-21  7. 0.1 mb to 0.01 mb           0.02 mb         0.01 mb         

40.2.2-22 e.  Horizontal Coverage         Global          Global          

40.2.2-23 f.  Vertical Coverage           surface to      Surface to      
                                          0.01 mb         0.01 mb         

40.2.2-24 g.  Measurement Range           180-335 K(TBR)  (TBD)           

40.2.2-25 h.  *Measurement Uncertainty                    0.5 K           

           Clear                                                          

40.2.2-26  1. *surface to 300 mb          1.6  K/ 1 km    0.5K/1km        
                                          layers                          

40.2.2-27  2. 300 mb to 30 mb             1.5 K/ 3 km     0.5K/1km        
                                          layers                          

40.2.2-28  3. 30 mb to 1 mb               1.5 K/ 5 km     0.5K/1km        
                                          layers                          

40.2.2-29  4. 1 mb to 0.01 mb             3.5 K/ 5 km     0.5K/1km        
                                          layers                          

           Cloudy (TBR)                                                   

40.2.2-30  5. *surface to 700 mb          2.5 K/ 1 km     0.5K/1km        
                                          layers                          

40.2.2-31  6. 700 mb to 300 mb            1.5 K/ 1 km     0.5K/1km        
                                          layers                          

40.2.2-32  7. 300 mb to 30 mb             1.5 K/ 3 km     0.5K/1km        
                                          layers                          

40.2.2-33                8. 30 mb to 1    1.5 K/ 5 km     0.5K/1km        
          mb                              layer                           

40.2.2-34  9. 1 mb to 0.01 mb             3.5 K/ 5 km     0.5K/1km        
                                          layers                          

40.2.2-35 i.  Mapping Uncertainty         5 km            1 km            

40.2.2-36 j.  Maximum Local Average       6 hrs           3 hrs           
          Revisit Time                                                    

40.2.2-37 k.  Maximum Local Refresh       (TBD)           (TBD)           



40.2.3 *Imagery

Imagery requirements fall into three classes: (a) explicit requirements on the EDR content, quality, reporting frequency, and timeliness, (b) requirements to be derived based on specific applications utilizing the imagery EDR, such as manual generation of cloud and sea ice data, and (c) requirements to be derived by the contractor based on requirements for other EDRs supported by the imagery. The explicit and application-related requirements are specified below. (Automated generation of cloud data is addressed in other EDRs and therefore will not be addressed below.)

40.2.3.1 Explicit EDR Requirements

Imagery is defined as the measured locally-averaged upwelling radiance or equivalent black body temperature from the earth's surface and atmosphere in one or more spectral bands, where the local averages are reported for the points of a two-dimensional approximately rectangular lattice. (The lattice is only approximately rectangular because of the curvature of the earth.) The form of the weighting function that determines the local average is constrained by the horizontal spatial resolution requirement. The number of spectral bands, band limit values, measurement ranges, and measurement uncertainty requirements are to be derived based on the application-related requirements given below and on the requirements of other EDRs supported by the imagery. However, at least one daytime visible, one nighttime visible, and at least one IR channel are required. Daytime and nighttime visible imagery must be merged so as to minimize the apparent transition across the terminator. Unless otherwise specified, the explicit EDR requirements below apply to each spectral band that is required for the Application-Related requirements of section 40.2.3.2 and at a minimum, to at least one daytime visible, one nighttime visible, and one IR channel (TBR). The explicit horizontal spatial resolution and mapping uncertainty requirements specified below do not apply to microwave imagery.

TRD40.2.3.1-1

Brightness temperatures from each microwave channel and polarization, if applicable, shall be available for display at the sampled resolution.


Para.                                     Thresholds      Objectives      
No.                                                                       

          a. *Horizontal Spatial                                          
          Resolution (HSR)                                                

40.2.3.1-  1. Global, at nadir            1.0 km          (TBD)           
2                                                                         

40.2.3.1-  2. Global, worst case          2.4 km          0.65 km         
3                                                                         

40.2.3.1-  3. Regional, at nadir          0.4 km          (TBD)           
4                                                                         

40.2.3.1-  4. Regional, worst case        0.8 km          0.1 km          
5                                                                         

40.2.3.1-  5. Nighttime Visible, worst    2.6 km          0.65 km         
6         case                                                            

40.2.3.1- b.  Horizontal Reporting        Less than or    Less than or    
7         Interval                        equal to        equal to        
                                          actual HSR      actual HSR      
                                          (gapless or     (gapless or     
                                          near gapless    near gapless    
                                          coverage)       coverage)       

          c.  Horizontal Coverage                                         

40.2.3.1-  1. Global                      Global          Global          
8                                         Resolution      Resolution      

40.2.3.1-  2. Regional                    Up to 1/2       Up to 1/2       
9                                         orbit,          orbit,          
                                          non-contiguous, non-contiguous, 
                                           commandable     commandable    
                                          by SOC          by SOC          

          d.  Measurement Range                                           

40.2.3.1-  1. Nighttime visible           4E-9 - 7E-4     Includes        
10                                        W/cm2-sr in     threshold       
                                          0.4-1.0 mm      range; aurora   
                                          band, or        & city lights   
                                          equivalent in   don't saturate  
                                          another band    imagery         

40.2.3.1- 2. Other bands                  Derived         Derived         
11                                                                        

40.2.3.1- e.  Measurement Uncertainty     Derived         Derived         
12                                                                        

          f.  Mapping Uncertainty                                         

40.2.3.1-  1. At nadir                    3 km            (TBD)           
13                                                                        

40.2.3.1-  2. Worst case                  4 km            0.5 km          
14                                                                        

40.2.3.1- g. *Maximum Local Average       4 hrs           (TBD)           
15        Revisit Time                                                    

40.2.3.1- h. *Maximum Local Refresh       6 hrs           (TBD)           
16                                                                        

40.2.3.1-                                 At any          (TBD)           
17        I. *Fraction of Revisit Times   location at                     
          Less Than a Specified Value     least 75% of                    
                                          the revisit                     
                                          times will be                   
                                          4 hours or                      
                                          less.                           



40.2.3.2 Application-Related Requirements (TBR)

The content, quality, and reporting frequency of the imagery shall suffice to support the following application-related requirements. These requirements, together with requirements of other EDRs supported by the imagery, determine the derived requirements in the explicit EDR requirement set above and may drive specified values of non-derived attributes to more stringent values. The content of the application-related data products is not part of the content of the imagery EDR. It is assumed that flowdown of application-related requirements to explicit imagery requirements will be performed by contractor simulation and modeling

40.2.3.2.1 Manually Generated Cloud Data

Manually generated cloud data are estimates of cloud cover and cloud type generated by a human analyst viewing the unprocessed and/or processed imagery derived from the unprocessed imagery, e.g., by data fusion, spatial rescaling, image enhancement, etc.

40.2.3.2.1.1 Cloud Cover

Cloud cover is defined as the fraction of a given area on the earth's surface for which a locally normal line segment extending between two given altitudes intersects a detectable cloud as defined in the Glossary. For manual analyses, cloud cover is estimated for a single atmospheric layer. Specifically, the altitudes are defined to be the surface of the earth and the altitude where the pressure is 0.1 mb. Haze, smoke, dust, and rain are not to be considered clouds. Cloud cover estimates are generated by a human analyst viewing unprocessed and/or processed imagery for contiguous square areas having side length equal to the horizontal cell size specified below.

Units: Dimensionless


Para. No.                                 Thresholds      Objectives      

            a. Horizontal Cell Size                                       

40.2.3.2-1   1. Global                    4 (TBR) times   2 times global  
                                          global HSR      HSR             

40.2.3.2-2   2. Regional                  4 (TBR) times   2 times         
                                          regional HSR    regional HSR    

40.2.3.2-3  b.  Horizontal Reporting      Horizontal      Horizontal      
            Interval                      cell size       cell size       

40.2.3.2-4  c.  Measurement Range         0 - 1, 0.1      0 - 1, 0.1      
                                          increments      increments      

40.2.3.2-5  d.  Measurement Uncertainty   0.1             0.1             



40.2.3.2.1.2 Cloud Type

Cloud types are defined as follows:

(1) Altocumulus (AC)

(2) Altocumulus Castellanus (ACCAS)

(3) Altocumulus (standing lenticular) (ACSL)

(4) Altostratus (AS)

(5) Cirrocumulus (CC)

(6) Cirrocumulus (standing lenticular) (CCSL)

(7) Cirrostratus (CS)

(8) Cirrus (CI)

(9) Cumulonimbus (CB)

(10) Cumulonimbus mama (Mammatocumulus) (CBMAM)

(11) Cumulus (CU)

(12) Cumulus Fractus (CUFRA)

(13) Towering Cumulus (TCU)

(14) Stratus Fractus (STFRA)

(15) Nimbostratus (NS)

(16) Stratocumulus (SC)

(17) Stratocumulus (standing lenticular) (SCSL)

(18) Stratus (ST)

Cloud typing not only entails a capability to distinguish between clouds of different type, but also a capability to distinguish clouds from other features, such as snow, cold water, cold land, haze, smoke, dust, etc. Therefore, the following additional types are defined:

(19) Obscured/not cloudy

(20) Clear

A given area is classified (TBR) as "obscured/not cloudy" if there are no detectable clouds within the atmosphere overlying the area and if the average vertical LOS extinction optical thickness of the atmosphere overlying the area is > 0.03 (TBR). A given area is classified (TBR) as "clear" if there are no detectable clouds as defined above overlying the area and if the average vertical LOS extinction optical thickness of the atmosphere overlying the area is < 0.03 (TBR). Note that other EDRs require the type of non-cloud obscuration to be discerned and identified, e.g., smoke, dust, sand, ash, etc.

Typing is performed by a human analyst viewing unprocessed and/or processed imagery for contiguous square areas having side length equal to the horizontal cell size specified below. The probability of correct typing is defined as the probability that a cell reported as being of type x is in fact of type x, where x is any of the types specified above.

Units: N/A


Para. No.                                Thresholds       Objectives      

             a. Horizontal Cell Size                                      

40.2.3.2.1.2  1. Global                  10 times global  2 times global  
-1                                       HSR               HSR            

40.2.3.2.1.2  2. Regional                10 times         2 times         
-2                                       regional HSR     regional HSR    

40.2.3.2.1.2 b.  Horizontal Reporting    Horizontal cell  Horizontal      
-3           Interval                    size             cell size       

40.2.3.2.1.2 c.  Measurement Range       clear,           clear,          
-4                                       obscured/not     obscured/not    
                                         cloudy, ST, CU,  cloudy, all 18  
                                         CI               cloud types     

             d.  Probability of Correct                                   
             Typing                                                       

40.2.3.2.1.2  1. Global                  85 %             90 %            
-5                                                                        

40.2.3.2.1.2  2. Regional                85 %             90 %            
-6                                                                        



40.2.3.2.2 Sea Ice Data

Sea ice data may be generated interactively by a human analyst viewing unprocessed or processed imagery at a computer workstation, or automatically via an algorithm. In addition to determination of ice edge location and ice concentration as described below, analysts will attempt to determine the thickness and size of leads and polynyas based on the imagery

40.2.3.2.2.1 Ice Edge Location

An ice edge is defined as the boundary between ice-covered sea water (ice concentration > 0.1(TBR)) and sea water not covered by ice (ice concentration 0.1(TBR)). Ice concentration is defined as the fraction of a given area sea or water covered by ice. An ice edge is typically provided as a contour on a map or in digital form as a set of latitude/longitude coordinates. The ice edge location error is defined as the distance between the estimated location of an ice edge and the nearest location of a true ice edge.

Units: Degrees latitude and longitude


Para. No                           Thresholds          Objectives            

40.2.3.2.2. a.  Horizontal         North of 36 deg     North of 36 deg       
1-1         Coverage               north latitude,     north latitude,       
                                   south of 50 deg     south of 50 deg       
                                   south latitude for  south latitude for    
                                   sea ice.            sea ice.              

40.2.3.2.2. b.  Measurement Range  Any latitude,       Any latitude,         
1-2                                longitude within    longitude within      
                                   coverage domain     coverage domain       

            c.  Measurement                                                  
            Uncertainty                                                      

40.2.3.2.2.  1. Global/Clear       1 km                (TBD)                 
1-3                                                                          

40.2.3.2.2.  2. Global/Cloudy      10 km               (TBD)                 
1-4                                                                          

40.2.3.2.2.  3. Regional/Clear     1 km                (TBD)                 
1-5                                                                          

40.2.3.2.2.  4. Regional/Cloudy    10 km               (TBD)                 
1-6                                                                          



40.2.3.2.2.2 Ice Concentration

Ice concentration is defined as the fraction of a given area of sea water covered by ice. It is typically derived from imagery and reported on ocean geographical charts for areas between contours generated by an analyst.

Units: Dimensionless


Para. No.                       Thresholds             Objectives         

40.2.3.2.2. a.  Horizontal      North of 36 (TBR) deg  North of 36 deg    
2-1         Coverage            north latitude, south  north latitude,    
                                of 50 deg south        south of 50 deg    
                                latitude for sea ice.  south latitude     
                                                       for sea ice.       

40.2.3.2.2. b.  Measurement     0 - 1, 0.1 increments  0 - 1, 0.1         
2-2         Range                                      increments         

40.2.3.2.2. c.  Measurement     0.1                    0.1                
2-3         Uncertainty                                                   



40.2.4 *Sea Surface Temperature (SST)

Sea surface temperature (SST) is defined as the skin temperature of the ocean surface water. The measured radiances should enable the derivation of both skin and surface layer (1 meter depth) sea surface temperature to the specifications listed below, though an EDR algorithm is only required for skin temperature. The requirements below apply only under clear conditions.

Units: K


Para.                               Thresholds         Objectives         
No.                                                                       

         a. *Horizontal Cell Size                                         

40.2.4-1  1. Global, at nadir       3 km               1 km               

40.2.4-2  2. Global, worst case     4 km               (TBD)              

40.2.4-3  3. *Regional, at nadir    1 km               0.25 km            

40.2.4-4  4. Regional, worst case   1.3 km             (TBD)              

40.2.4-5 b.  Horizontal Reporting   Local Horizontal   Local Horizontal   
         Interval                   Cell Size          Cell Size          

         c.  Horizontal Coverage                                          

40.2.4-6  1.  Global                Oceans             Oceans             

40.2.4-7  2.  Regional              Oceans, up to 1/2  Oceans, up to 1/2  
                                    orbit,             orbit,             
                                    non-contiguous,    non-contiguous,    
                                    commandable by     commandable by     
                                    SOC                SOC                

40.2.4-8 d.  Measurement Range      271 K - 313 K      271 K - 313 K      

40.2.4-9 e.  *Measurement           0.5 K (TBR)        0.1 K              
         Uncertainty                                                      

40.2.4-1 f.  Measurement Accuracy   0.2 K              0.1 K              
0                                                                         

40.2.4-1 g.  Measurement Precision  (TBD)              0.1K               
1                                                                         

         h.  Mapping Uncertainty                                          

40.2.4-1  1. Global, at nadir       1 km               0.5 km             
2                                                                         

40.2.4-1  2. Global, worst case     3 km               (TBD)              
3                                                                         

40.2.4-1  3. Regional, at nadir     1 km               0.1 km             
4                                                                         

40.2.4-1  4. Regional, worst case   3 km               (TBD)              
5                                                                         

40.2.4-1 i.  Maximum Local Average  6 hrs              3 hrs              
6        Revisit Time                                                     

40.2.4-1 j.  Maximum Local Refresh  (TBD)              (TBD)              
7                                                                         



40.2.5 *Sea Surface Winds (Speed and Direction)

Atmospheric wind speed and direction at the sea/atmosphere interface. This parameter is to be reported at 19.5 meters above sea level.

Units:

Speed, m/s.

Direction, degrees from geographic (true) north.


Para.                               Thresholds         Objectives          
No.                                                                        

40.2.5-1  a.  Horizontal Cell Size  20 km              1 km                

40.2.5-2  b.  Horizontal Reporting  (TBD)              (TBD)               
          Interval                                                         

40.2.5-3  c.  Horizontal Coverage   Oceans             Oceans              

          d.  Measurement Range                                            

40.2.5-4   1. Speed                 3 - 25 m/s         1 - 50 m/s          

40.2.5-5   2. Direction             0 - 360 deg        0 - 360 deg         

          e.  *Measurement                                                 
          Accuracy                                                         

40.2.5-6   1. *Speed                2 m/s or 20 % of   1 m/s or 10 % of    
                                    true value,        true value,         
                                    whichever is       whichever is        
                                    greater            greater             

40.2.5-7   2. Direction             20 deg for wind    10 deg              
                                    speeds greater                         
                                    than 8 m/s.                            
                                    45 deg (TBR) for                       
                                    wind speeds less                       
                                    than 8 m/s                             

          f.  Measurement                                                  
          Precision                                                        

40.2.5-8   1. Speed                 1 m/s              1 m/s               

40.2.5-9   2. Direction             10 deg             10 deg              

40.2.5-10 g.  Mapping Uncertainty   5 km               1 km                

40.2.5-11 h.  Maximum Local         6 hrs              1 hrs               
          Average Revisit Time                                             

40.2.5-12 i.  Maximum Local         (TBD)              (TBD)               
          Refresh                                                          



40.2.6 *Soil Moisture

Total water in all phases in the soil or in a surface layer over soil. The threshold requirement is to measure soil moisture only within a thin layer at the surface (0.1 cm thick) and only for bare soil in regions with known soil types. The objective is to measure a moisture profile for any soil, whether bare or not, and whether or not the soil type is known.

Units: cm/m (cm of water per meter of soil depth)


Para.                                   Thresholds      Objectives        
No.                                                                       

          a. Horizontal Cell Size                                         

40.2.6-1   1. Clear, at nadir (TBR)     1 km            (TBD)             

40.2.6-2   2. Clear, worst case (TBR)   4 km            2 km              

40.2.6-3   3. Cloudy, at nadir          40 km           2 km              

40.2.6-4   4. Cloudy, worst case        50 km           (TBD)             

40.2.6-5  b.  Horizontal Reporting      (TBD)           (TBD)             
          Interval                                                        

40.2.6-6  c.  Vertical Cell Size        0.1 cm          5 cm              

40.2.6-7  d.  Vertical Reporting        N/A (single     5 cm              
          Interval                      value                             
                                        reported)                         

40.2.6-8  e.  Horizontal Coverage       Land            Land              

40.2.6-9  f.  *Vertical Coverage (TBR)  surface to      Surface to -80    
                                        -0.1 cm (skin   cm                
                                        layer)                            

40.2.6-10 g.  Measurement Range         0 - 100 cm/m    0 - 100 cm/m      
                                        (TBR)                             

          h.  Measurement Uncertainty                                     

40.2.6-11  1. Clear, Bare soil in       10 cm/m (TBR)   Surface:  1 cm/m  
          regions with known soil                       Total 80 cm       
          types (smaller horizontal                     column: greater   
          cell size)                                    of 5% or 0.013    
                                                        cm/m  (130 g/m3)  

40.2.6-12  2. Cloudy , Bare soil in     20 cm/m (TBR)   Surface:  1 cm/m  
          regions with known soil                       Total 80 cm       
          types (greater horizontal                     column: greater   
          cell size)                                    of 5% or 0.013    
                                                        cm/m  (130 g/m3)  

40.2.6-13 i.  Mapping Uncertainty       3 km            1 km              

40.2.6-14 j.  Maximum Local Average     8 hrs           3 hrs             
          Revisit Time                                                    

40.2.6-15 k.  Maximum Local Refresh     (TBD)           (TBD)             



40.3 Atmospheric EDRs

40.3.1 Aerosols

Aerosols are defined as suspensions of liquid droplets or solid particles in the atmosphere. Aerosols include, but are not limited to, smoke, dust, sand, volcanic ash, sea spray, polar stratospheric clouds, and smog. Water and ice clouds are also aerosols, but because of the frequency of their occurrence and their importance to military operations, they are addressed separately in another EDR (See Sec. 40.2.3, Imagery).

40.3.1.1 Aerosol Optical Thickness

Aerosol optical thickness, for this EDR, is defined (TBS) as the extinction (scattering + absorption) vertical optical thickness of aerosols in the 0.4 to 1.0 um band in atmospheric layers of specified height and thickness. The narrow bands used to derive the aerosol particle size parameter may be used to derive aerosol optical thickness in the 0.4 to 1.0 mm band. Optical thickness (t) is related to transmission (t) by t= exp (-t). The requirements below apply only under clear conditions.

Units: Dimensionless


Para. No.                                 Thresholds         Objectives   

40.3.1.1-1 a. Horizontal Cell Size        10 km              1 km         

40.3.1.1-2 b.  Horizontal Reporting       (TBD)              (TBD)        
           Interval                                                       

40.3.1.1-3 c.  Vertical Cell Size         30 km (Total       50 km        
                                          Column)                         

40.3.1.1-4  1. 0 - 2 km                   N/A                0.25 km      

40.3.1.1-5  2. 2 - 5 km                   N/A                0.5 km       

40.3.1.1-6  3. > 5 km                     N/A                1 km         

40.3.1.1-7 d.  Vertical Reporting         N/A (Total         Vertical     
           Interval                       Column)            cell size    

40.3.1.1-8 e.  Horizontal Coverage        Global             Global       

40.3.1.1-9 f.  Vertical Coverage          0 - 30 km          0 - 50 km    

40.3.1.1-1 g.  Measurement Range          0 - 2              0 - 10       
0                                                                         

           h.  Measurement Accuracy       0.03 (TBR) over                 
40.3.1.1-1               1.  Over Ocean   ocean,             0.01         
1                        2.  Over Land    0.2 (TBR) over     0.1          
40.3.1.1-1                                land                            
2                                                                         

40.3.1.1-1 i.  Measurement Precision      0.03               0.01         
3                                                                         

40.3.1.1-1 j.  Long Term Stability        0.01               0.003        
4                                                                         

40.3.1.1-1 k.  Mapping Uncertainty        4 km               1 km         
5                                                                         

40.3.1.1-1 l.  Maximum Local Average      6 hrs (TBR)        4hrs(TBR)    
6          Revisit Time                                                   

40.3.1.1-1 m.  Maximum Local Refresh      (TBD)              (TBD)        
7                                                                         



40.3.1.2 Aerosol Particle Size Parameter

The aerosol particle size parameter, for this EDR, is defined (TBR) as the Angstrom wavelength exponent "alpha" (a), where

a = - D ln t/D ln l

t is the extinction (scattering + absorption) vertical optical thickness of the aerosols within specified layers of the atmosphere, and l is wavelength within the visible/infrared spectrum (< 10 mm). Measurements of optical thickness in at least two different narrow wavelength bands are required to measure, and the "delta" in the above equation refers to the difference between the measurements in these two bands. The two narrow bands should be separated by at least 200 nm in wavelength. If the aerosol particle size distribution is given by an inverse power law, such as a Junge distribution, then alpha can be related to the exponent in the power law. The requirements below apply only under clear conditions.

Units: Dimensionless.


Para.                                Thresholds           Objectives      
No.                                                                       

40.3.1.2- a.  Horizontal Cell Size   10 km                1 km            
1                                                                         

40.3.1.2- b.  Horizontal Reporting   (TBD)                (TBD)           
2         Interval                                                        

40.3.1.2- c.  Vertical Cell Size     30 km (Total         50 km           
3                                    Column)                              

40.3.1.2-  1. 0 - 2 km               N/A                  0.25 km         
4                                                                         

40.3.1.2-  2. 2 - 5 km               N/A                  0.5 km          
5                                                                         

40.3.1.2-  3. > 5 km                 N/A                  1 km            
6                                                                         

40.3.1.2- d.  Vertical Reporting     N/A (Total Column)   Vertical cell   
7         Interval                                        size            

40.3.1.2- e.  Horizontal Coverage    Over ocean only      Global          
8                                                                         

40.3.1.2- f.  Vertical Coverage      0 - 30 km            0 - 50 km       
9                                                                         

40.3.1.2- g.  Measurement Range      -1 to +3             -2 to +4        
10                                                                        

40.3.1.2- h.  Measurement Accuracy   0.3 over ocean       0.1             
11                                                                        

40.3.1.2- i.  Measurement Precision  0.3                  0.1             
12                                                                        

40.3.1.2- j.  Long Term Stability    0.1                  0.03            
13                                                                        

40.3.1.2- k.  Mapping Uncertainty    4 km                 1 km            
14                                                                        

40.3.1.2- l.  Maximum Local Average  6 hrs                4 hrs(TBR)      
15        Revisit Time                                                    

40.3.1.2- m.  Maximum Local Refresh  (TBD)                (TBD)           
16                                                                        



40.3.1.3 Suspended Matter

As a threshold the required content of this EDR is the identification of specified classes of suspended matter in instances in which suspended matter is detected. There are no explicit detectability requirements for the types of suspended matter of interest. The capability to detect suspended matter, and all other aerosols, will be a by-product of the capabilities required by other EDRs. As a threshold, dust, sand, and ash are to be identified for a vertical column of the atmosphere, if detected. As an objective, these types as well as sea salt, smoke, and radioactive smoke are to be typed in 0.2 km layers within a vertical column of the atmosphere. Furthermore, as an objective, the concentration of the suspended matter, if detected, is also to be provided. The requirements below apply only under clear conditions.

Units:

Typing: N/A

Concentration: mg/m3


Para. No.                            Thresholds         Objectives         

40.3.1.3-1 a. Horizontal Cell Size   3 km               1 km               

40.3.1.3-2 b.  Horizontal Reporting  Local Horizontal   Local Horizontal   
           Interval                  Cell Size          Cell Size          

40.3.1.3-3 c.  Vertical Cell Size    30 km (Total       0.2 km             
                                     Column)                               

40.3.1.3-4 d.  Vertical Reporting    N/A                Vertical Cell      
           Interval                                     Size               

40.3.1.3-5 e.  Horizontal Coverage   Global             Global             

40.3.1.3-6 f.  Vertical Coverage     0-30 km            (TBD)              

           g.  Measurement Range                                           

40.3.1.3-7  1.  Type                 dust, sand, ash,   dust, sand, ash,   
                                     other              sea salt, smoke,   
                                                        radioactive        
                                                        smoke,other        

40.3.1.3-8  2.  Concentration        N/A                 0 - 100 mg/m3     
                                                        (smoke)            

40.3.1.3-9 h.  Probability of        (TBD)              (TBD)              
           Correct Typing                                                  

40.3.1.3-1 i.  Measurement           N/A                (TBD)              
0          Uncertainty                                                     
           (concentration)                                                 

40.3.1.3-1 j.  Mapping Uncertainty   3 km               0.1 km             
1                                                                          

40.3.1.3-1 k.  Maximum Local         12 hrs             3 hrs              
2          Average Revisit Time                                            

40.3.1.3-1 l.  Maximum Local         (TBD)              (TBD)              
3          Refresh                                                         



40.3.2 Ozone Total Column/Profile (DOC)

Ozone total column is defined as the amount of ozone in a vertical column of the atmosphere measured in Dobson Units (atm-cm). Ozone vertical profile is defined as the volumetric concentration of ozone in specified segments of a vertical column of the atmosphere measured in parts per million volume (ppmv). For this EDR vertical cell size is the vertical height of the column segment and the vertical reporting interval specifies the locations of the column segment bottoms for which ozone parameters must be reported. The requirements below apply only under clear conditions and above clouds.

Units:

Total column: atm-cm

Profile: ppmv


Para.                                 Thresholds       Objectives          
No.                                                                        

          a.  Horizontal Cell Size                                         

40.3.2-1   1. Total Column            50 km @ nadir    50 km               

40.3.2-2   2. Profile                 250 km           250 km              

40.3.2-3  b.  Horizontal Reporting    (TBD)            (TBD)               
          Interval                                                         

          c.  Vertical Cell Size                                           

40.3.2-4   1. Total Column            60 km            60 km               

40.3.2-5   2. Profile, 0 - 10 km      N/A              3 km                

40.3.2-6   3. Profile, 10 - 25 km     5 km             1 km                

40.3.2-7   4. Profile, 25 - 60 km     5 km             3 km                

          d.  Vertical Reporting                                           
          Interval                                                         

40.3.2-8   1. Total Column            N/A              N/A                 

40.3.2-9   2. Profile                 Vertical Cell    Vertical Cell Size  
                                      Size                                 

40.3.2-10 e.  Horizontal Coverage     Global           Global              

40.3.2-11 f.  Vertical Coverage       10 - 60 km       0 - 60 km           

          g.  Measurement Range                                            

40.3.2-12  1. Total Column            0.05 - 0.65      0.05 - 0.65 atm-cm  
                                      atm-cm                               

40.3.2-13  2. Profile, 0 - 10 km      N/A              0.01 - 3 ppmv       

40.3.2-14  3. Profile, 10 - 60 km     0.1 - 15 ppmv    0.1 - 15 ppmv       

          h.  Measurement Accuracy                                         

40.3.2-15   1. Total Column           0.015 atm-cm     0.005 atm-cm        

40.3.2-16  2. Profile, 0 - 10 km      N/A              10 %                

40.3.2-17  3. Profile, 10 - 15 km     20 % or 0.1      10 %                
                                      ppmv                                 

40.3.2-18  4. Profile, 15 - 60 km     10 % or 0.05     5 %                 
                                      ppmv                                 

          i.  Measurement Precision                                        

40.3.2-19  1. Total Column            0.001 atm-cm     0.001 atm-cm        

40.3.2-20  2. Profile, 0 - 10 km      N/A              10 %                

40.3.2-21  3. Profile, 10 - 15 km     10 %             3 %                 

40.3.2-22  4. Profile, 15 - 50 km     3 %              1 %                 

40.3.2-23  5. Profile, 50 - 60 km     10 %             3 %                 

          j.  Long Term Stability                                          

40.3.2-24  1. Total Column            1 %              0.5 %               

40.3.2-25  2. Profile                 2 %              1 %                 

          k. Mapping Uncertainty                                           

40.3.2-26  1. Total Column, at nadir  5 km             5 km                

40.3.2-27  2. Profile                 25 km            25 km               

          l.  Maximum Local Average                                        
          Revisit Time                                                     

40.3.2-28  1. Total Column            24 hrs           24 hrs              

40.3.2-29  2. Profile                 7 days           24 hrs              

          m.  Maximum Local Refresh                                        

40.3.2-30  1. Total Column            (TBD)            (TBD)               

40.3.2-31  2. Profile                 (TBD)            (TBD)               



40.3.3 Precipitable Water

Precipitable water is defined as the total equivalent water in a vertical column of the atmosphere per unit cross-sectional area. The requirements below apply under both clear and cloudy conditions.

Units: mm of condensed vapor


Para.                                   Thresholds           Objectives    
No.                                                                        

40.3.3- a. Horizontal Cell Size         25 km (TBR)          1 km          
1                                                                          

40.3.3- b. Horizontal Reporting         (TBD)                (TBD)         
2       Interval                                                           

40.3.3- c. Horizontal Coverage          Global               Global        
3                                                                          

40.3.3- d. Measurement Range            0 - 75 mm            0 - 100 mm    
4                                                                          

40.3.3- e. Measurement Accuracy         greater of 10 % or   1 mm          
5                                       2 mm                               

40.3.3- f. Measurement Precision        1 mm                 1mm           
6                                                                          

40.3.3- g. Mapping Uncertainty          3 km                 0.1 km        
7                                                                          

40.3.3- h.  Maximum Local Average       6 hrs                3 hrs         
8       Revisit Time                                                       

40.3.3- i.  Maximum Local Refresh       (TBD)                (TBD)         
9                                                                          



40.3.4 Precipitation (Type, Rate)

The required data products are precipitation rate and identification of type as rain or ice. Unless otherwise specified, the requirements in the table below apply to both precipitation type and rate and apply under both clear and cloudy conditions.

Units:

Rate: mm/hr

Type: rain, , ice


Para.                                     Thresholds        Objectives    
No.                                                                       

40.3.4-1  a.  Horizontal Cell Size        15 km             0.1 km        

40.3.4-2  b.  Horizontal Reporting        (TBD)             (TBD)         
          Interval                                                        

40.3.4-3  c.  Horizontal Coverage         Global            Global        

          d.  Measurement Range                                           

40.3.4-4   1.  Precipitation Rate         0 - 50(TBR)       0 - 250       
                                          mm/hr             mm/hr         

40.3.4-5   2.  Precipitation Type         rain and ice      rain and ice  

40.3.4-6  e.  Measurement Accuracy,       2 mm/hr           2 mm/hr       
          Precip. Rate                                                    

40.3.4-7  f.  Measurement Precision,      1 mm/hr           1 mm/hr       
          Precip. Rate                                                    

40.3.4-8  g.  Correct Typing              (TBD) %           (TBD) %       
          Probability, Precip. Type                                       

40.3.4-9  h.  Mapping Uncertainty         3 km              0.1 km        

40.3.4-10 i.   Maximum Local Average      8 hrs (TBR)       3 hrs         
          Revisit Time                                                    

40.3.4-11 j.   Maximum Local Refresh      (TBD)             (TBD)         



40.3.5 Pressure Profile (TBR)

A pressure profile is a set of estimates of the atmospheric pressure at specified altitudes above the earth's surface. The requirements below apply under both clear and cloudy conditions.

Units: mb


Para.                                     Thresholds       Objectives     
No.                                                                       

40.3.5-1  a.  Horizontal Cell Size        25 km            5 km           

40.3.5-2  b.  Horizontal Reporting        (TBD)            (TBD)          
          Interval                                                        

40.3.5-3  c.  Vertical Cell Size          1 km             0 km           

          d.  Vertical Reporting                                          
          Interval                                                        

40.3.5-4   1. 0 - 2 km                    1 km             0.25 km        

40.3.5-5   2. 2 - 5 km                    1 km             0.5 km         

40.3.5-6   3. > 5 km                      1 km             1 km           

40.3.5-7  e.  Horizontal Coverage         Global           Global         

40.3.5-8  f.  Vertical Coverage           0 - 30 km        0 - 30 km      

40.3.5-9  g.  Measurement Range           10 - 1050 mb     10 - 1050 mb   

          h.  Measurement Accuracy                                        

40.3.5-10               1. 0 - 2 km       1% (TBR)                        

40.3.5-11  2. 2 - 10 km                   1% or 10 mb      3 % (TBR)      

40.3.5-12  3. 10 - 30 km                  1% or 1 mb       0.5 %          

40.3.5-13 i.  Measurement Precision       4 mb             2 mb           

40.3.5-14 k. Mapping Uncertainty          7 km             1 km           

40.3.5-15 l.  Maximum Local Average       12 hrs           1 hr           
          Revisit Time                                                    

40.3.5-16 m.  Maximum Local Refresh       (TBD)            (TBD)          



40.3.6 Total Water Content

Total water content is defined as the water vapor, cloud liquid water, and cloud ice liquid equivalentin specified segments of a vertical column of the atmosphere. For this EDR vertical cell size is the vertical height of the column segment and the vertical reporting interval specifies the locations of the column segment bottoms for which cloud liquid water must be reported. The requirements below apply under both clear and cloudy conditions.

Units: kg/m2


Para.                                    Thresholds       Objectives      
No.                                                                       

40.3.6-1  a.  Horizontal Cell Size       20 km            10 km           

40.3.6-2  b.  Horizontal Reporting       (TBD)            (TBD)           
          Interval                                                        

40.3.6-3  c.  Vertical Cell Size         3 km (TBR)       1 km            

40.3.6-4  d.  Vertical Reporting         Vertical cell    Vertical cell   
          Interval                       size             size            

40.3.6-5  e.  Horizontal Coverage        Global           Global,         

40.3.6-6  f.  Vertical Coverage          0 - 20 km        0 - (TBD) km    

40.3.6-7  g.  Measurement Range          0-200 kg         (TBD)           

          h.  Measurement Uncertainty                                     

40.3.6-8    1.Point Measurement          2 kg/m2          (TBD)           

40.3.6-9   2. Global Average             1kg/m2           (TBD)           

40.3.6-10 i. Mapping Uncertainty         7 km             7 km            

40.3.6-11 j.  Maximum Local Average      8 hrs            3 hrs           
          Revisit Time                                                    

40.3.6-12 k.  Maximum Local Refresh      (TBD)            (TBD)           



40.4 Cloud EDRs

In this section "cloud" always means "detectable cloud" as defined in the glossary.

40.4.1 Cloud Base Height

Cloud base height is defined as the height above ground level where cloud bases occur. More precisely, for a cloud covered earth location, cloud base height is the set of altitudes of the bases of the clouds that intersect the local vertical at this location. The reported heights are horizontal spatial averages over a cell, i.e., a square region of the earth's surface. If a cloud layer does not extend over an entire cell, the spatial average is limited to the portion of the cell that is covered by the layer. As a threshold, only the height of the base of the lowest altitude cloud layer is required and the objective is to report cloud base height for all distinct cloud layers.

Units: km


Para.                                     Thresholds      Objectives      
No.                                                                       

40.4.1-1 a. Horizontal Cell Size          25 km           10 km           

40.4.1-2 b. Horizontal Reporting          (TBD)           (TBD)           
         Interval                                                         

40.4.1-3 c. Horizontal Coverage           Global          Global          

         d. Vertical Cell Size            N/A             N/A             

40.4.1-4 e.  Vertical Reporting Interval  Total Column    0.25km          

40.4.1-5 f. Measurement Range             0 - 15 km       0 - 30 km       

40.4.1-6 g. Measurement Uncertainty       2 km (TBR)      0.25 km         

40.4.1-7 h. Mapping Uncertainty           4 km            1 km            

40.4.1-8 i. Maximum Local Average         6 hrs           4 hrs           
         Revisit Time                                                     

40.4.1-9 j. Maximum Local Refresh         (TBD)           (TBD)           



40.4.2 Cloud Cover/Layers

Cloud cover is defined (TBR) as the fraction of a given area on the earth's surface for which a locally normal line segment extending between two given altitudes intersects a cloud. As a threshold, cloud cover is required for up to four layers of the atmosphere between the surface and an altitude of 30 km. As an objective, cloud cover is required for contiguous, 0.1 km thick layers at 0.1 km increments in altitude, from the surface of the earth to an altitude of 30 km.

Units: dimensionless


Para.                                     Thresholds      Objectives      
No.                                                                       

40.4.2-1  a.  Horizontal Cell Size        25 km           2 km            

40.4.2-2  b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

          c.  Vertical Cell Size          N/A             N/A             

40.4.2-3  d.  Vertical Reporting          Up to 4 layers  0.1 km          
          Interval                                                        

40.4.2-4  e.  Horizontal Coverage         Global          Global          

40.4.2-5  f.  Vertical Coverage           0 - 20 km       0 - 30 km       

40.4.2-6  g.  Measurement Range           0 - 1.0         0 - 1.0         

40.4.2-7  h.  Measurement Accuracy        0.1             0.05            

40.4.2-8  i.  Measurement Precision       0.15            0.025           

40.4.2-9  j.  Mapping Uncertainty         4 km            1 km            

40.4.2-10 k. Maximum Local Average        6 hrs           4 hrs           
          Revisit Time                                                    

40.4.2-11 l.  Maximum Local Refresh       (TBD)           (TBD)           



40.4.3 Cloud Effective Particle Size

Effective cloud particle size is defined as the ratio of the third moment of the drop size distribution to the second moment, averaged over a layer of air within a cloud.

Units: m


Para.                                   Thresholds         Objectives        
No.                                                                          

40.4.3-1 a.  Horizontal Cell Size       50 km              10 km             

40.4.3-2 b.  Horizontal Reporting       (TBD)              (TBD)             
         Interval                                                            

40.4.3-3 c.  Vertical Cell Size         Vertical           Vertical          
                                        Reporting          Reporting         
                                        Interval           Interval          

40.4.3-4 d.  Vertical Reporting         1.0 km(TBR)        0.3 km            
         Interval                                                            

40.4.3-5 e.  Horizontal Coverage        Global             Global            

40.4.3-6 f.  Vertical Coverage          0 - 20 km          0 - 30 km         

40.4.3-7 g.  Measurement Range          0 - 50 m           (TBD)             

40.4.3-8 h.  Measurement Accuracy       greater of 10 %    greater of 5 %    
                                        or 4 m             or 2 m            

40.4.3-9 i.  Measurement Precision      greater of 5 % or  2 %               
                                        2 m                                  

40.4.3-1 j.  Long Term Stability        2 %                1 %               
0                                                                            

40.4.3-1 k.  Mapping Uncertainty        4 km               1 km              
1                                                                            

40.4.3-1 l.  Maximum Local Average      8 hrs              3 hrs             
2        Revisit Time                                                        

40.4.3-1 m.  Maximum Local Refresh      (TBD)              (TBD)             
3                                                                            



40.4.4 Cloud Ice Water Path (DOC)

Cloud ice water path is defined as the equivalent amount of water within cloud ice particles in a specified segment of a vertical column of the atmosphere. For this EDR vertical cell size is the vertical height of the column segment and the vertical reporting interval specifies the locations of the column segment bottoms for which cloud ice water path must be reported.

Units: kg/m2


Para.                                     Thresholds        Objectives     
No.                                                                        

40.4.4-1 a.  Horizontal Cell Size         50 km             10 km          

40.4.4-2 b.  Horizontal Reporting         (TBD)             (TBD)          
         Interval                                                          

40.4.4-3  c.  Vertical Cell Size          15 km (Total      Vertical       
                                          Column)           Reporting      
                                                            Interval       

40.4.4-4 d.  Vertical Reporting Interval  N/A (Total        0.3 km         
                                          Column)                          

40.4.4-5 e.  Horizontal Coverage          Global            Global         

40.4.4-6 f.  Vertical Coverage            0 - 20 km         0 - 20 km      

40.4.4-7 g.  Measurement Range            0 - 2.6           0 - 10  kg/m2  
                                          kg/m2(TBR)                       

40.4.4-8 h.  Measurement Accuracy         10 % or 5 g/m2    5 %            
                                          (TBR)                            

40.4.4-9 i.  Measurement Precision        5 %               2 %            

40.4.4-1 j.  Long Term Stability          2 %               1 %            
0                                                                          

40.4.4-1 k. Mapping Uncertainty           4 km              1 km           
1                                                                          

40.4.4-1 l.  Maximum Local Average        6 hrs             3 hrs          
2        Revisit Time                                                      

40.4.4-1 m.  Maximum Local Refresh        (TBD)             (TBD)          
3                                                                          



40.4.5 Cloud Liquid Water

Cloud liquid water is defined as the equivalent amount of water within cloud particles in a specified segment of a vertical column of the atmosphere. For this EDR vertical cell size is the vertical height of the column segment and the vertical reporting interval specifies the locations of the column segment bottoms for which cloud liquid water must be reported.

Units: mm


Para.                                    Thresholds       Objectives       
No.                                                                        

40.4.5-1 a.  Horizontal Cell Size        20 km            5 km             

40.4.5-2 b.  Horizontal Reporting        (TBD)            (TBD)            
         Interval                                                          

40.4.5-3 c.  Vertical Cell Size          30 km  (Total    Vertical         
                                         Column)          Reporting        
                                                          Interval         

40.4.5-4 d.  Vertical Reporting          N/A (Total       0.3 km           
         Interval                        Column)                           

40.4.5-5 e.  Horizontal Coverage         Global           Global           

40.4.5-6 f.  Vertical Coverage           0 - 20 km        0 - 30 km        

40.4.5-7 g.  Measurement Range           0 - 50 mm        (TBD)            

         h.  Measurement                                                   
         Uncertainty(TBR)                                                  

40.4.5-8  1. Over ocean                  0.25 mm          0.01 mm          

40.4.5-9  2. Over land                   0.5 mm           0.01 mm          

40.4.5-1 i.  Mapping Uncertainty         7 km             1 km             
0                                                                          

40.4.5-1 j.  Maximum Local Average       8 hrs            4 hrs            
1        Revisit Time                                                      

40.4.5-1 k.  Maximum Local Refresh       (TBD)            (TBD)            
2                                                                          



40.4.6 Cloud Optical Thickness (IORD Name: Cloud Optical Depth/Transmissivity)

Cloud optical thickness is defined as the extinction (scattering + absorption) vertical optical thickness of all cloud layers in a vertical column of the atmosphere. Optical thickness (t) is related to transmittance (t) by t= exp (-t). Optical thickness is wavelength dependent and is to be measured in at least two narrow bands centered at 450 nm (TBR) and 850 nm (TBR), with TBD nm bandwidth.

Units: Dimensionless


Para.                                     Thresholds      Objectives      
No.                                                                       

40.4.6-1  a.  Horizontal Cell Size        50 km           10 km           

40.4.6-2  b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

40.4.6-3  c.  Horizontal Coverage         Global          Global          

40.4.6-4  d.  Measurement Range           0 - 10 optical  (TBD)           
                                          depth (TBR))                    

40.4.6-5  e.  Measurement Accuracy        greater of 10   greater of 5 %  
                                          % or 0.05       and (TBD)       
                                          optical depth                   

40.4.6-6  f.  Measurement Precision       greater of 5 %  greater of 2 %  
                                          or 0.025        and (TBD)       
                                          optical depth                   

40.4.6-7  g.  Long Term Stability         2 %             1 %             

40.4.6-8  h.  Mapping Uncertainty         4 km            1 km            

40.4.6-9  i.  Maximum Local Average       8 hrs           3 hrs           
          Revisit Time                                                    

40.4.6-10 j.  Maximum Local Refresh       (TBD)           (TBD)           



40.4.7 Cloud Top Height

Cloud top height is defined for each cloud-covered earth location as the set of heights of the tops of the cloud layers overlying the location. The reported heights are horizontal spatial averages over a cell, i.e., a square region of the earth's surface. If a cloud layer does not extend over an entire cell, the spatial average is limited to the portion of the cell that is covered by the layer. Cloud top height is not defined or reported for cells that are clear. As a threshold, only the height at the top of the highest altitude cloud layer is required. The objective is to report the cloud top height for all distinct cloud layers.

Units: km


Para.                                            Thresholds   Objectives  
No.                                                                       

40.4.7-1 a.  Horizontal Cell Size                25 km        10 km       

40.4.7-2 b.  Horizontal Reporting Interval       (TBD)        (TBD)       

40.4.7-3 c.  Horizontal Coverage                 Global       Global      

         d.  Vertical Cell Size                  N/A          N/A         

40.4.7-4 e.  Vertical Reporting Interval         Up to 4      0.25 km     
                                                 layers                   

40.4.7-5 f.  Measurement Range                   0-20 km      (TBD)       

         g.  Measurement Accuracy                                         

40.4.7-6  1. Cloud layer optical thickness >     1.0 km       0.3 km      
         0.1 (TBR)                               (TBR)                    

40.4.7-7  2.  Cloud layer optical thickness      2 km         0.3 km      
         0.1 (TBR)                                                        

40.4.7-8 h.  Measurement Precision               0.3 km       0.15 km     

40.4.7-9 i.  Long Term Stability                 0.2 km       0.1 km      

40.4.7-1 j.  Mapping Uncertainty                 4 km         1 km        
0                                                                         

40.4.7-1 k.  Maximum Local Average Revisit Time  8 hrs        6 hrs       
1                                                                         

40.4.7-1 l.  Maximum Local Refresh               (TBD)        (TBD)       
2                                                                         



40.4.8 Cloud Top Pressure (DOC)

Cloud top pressure is defined for each cloud-covered earth location as the set of atmospheric pressures at the tops of the cloud layers overlying the location. The reported pressures are horizontal spatial averages over a cell, i.e., a square region of the earth's surface. If a cloud layer does not extend over an entire cell, the spatial average is limited to the portion of the cell that is covered by the layer. Cloud top pressure is not defined or reported for cells that are clear. As a threshold, only the pressure at the top of the highestaltitude cloud layer is required. The objective is to report the cloud top pressure for all distinct cloud layers.

Units: mb


Para.                                     Thresholds      Objectives      
No.                                                                       

40.4.8-1  a.  Horizontal Cell Size        15 km           10 km           

40.4.8-2  b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

40.4.8-3  c.  Horizontal Coverage         Global          Global          

40.4.8-4  d.  Measurement Range           50-1050 mb      (TBD)           

          e.  Measurement Accuracy                                        

40.4.8-5   1. surface - 3 km              100 mb          30 mb           

40.4.8-6   2. 3 - 7 km                    75 mb           22 mb           

40.4.8-7   3. > 7 km                      50 mb           15 mb           

          f.  Measurement Precision                                       

40.4.8-8   1. surface - 3 km              50 mb           10 mb           

40.4.8-9   2. 3 - 7 km                    38 mb           7 mb            

40.4.8-10  3. > 7 km                      25 mb           5 mb            

          g.  Long Term Stability (TBR)                                   

40.4.8-11  1. surface - 3 km              10 mb           3 mb            

40.4.8-12  2. 3 - 7 km                    7 mb            2 mb            

40.4.8-13  3. > 7 km                      5 mb            1 mb            

40.4.8-14 h.  Mapping Uncertainty         4 km            1 km            

40.4.8-15 i.  Maximum Local Average       8 hrs           3 hrs           
          Revisit Time                                                    

40.4.8-16 j.  Maximum Local Refresh       (TBD)           (TBD)           



40.4.9 Cloud Top Temperature

Cloud top temperature is defined for each cloud-covered earth location as the set of atmospheric temperatures at the tops of the cloud layers overlying the location. The reported temperatures are horizontal spatial averages over a cell, i.e., a square region of the earth's surface. If a cloud layer does not extend over an entire cell, the spatial average is limited to the portion of the cell that is covered by the layer. Cloud top temperature is not defined or reported for cells that are clear. As a threshold, only the temperature at the top of the highest altitude cloud layer is required. The objective is to report the cloud top temperature for all distinct cloud layers.

Units: K


Para.                                            Thresholds   Objective 
No.                                                           s         

40.4.9-1  a.  Horizontal Cell Size               25 km        10 km     

40.4.9-2  b.  Horizontal Reporting Interval      (TBD)        (TBD)     

40.4.9-3  c.  Horizontal Coverage                Global       Global    

40.4.9-4  d.  Measurement Range                  180-310 K    (TBD)     

          e.  Measurement Accuracy                                      

40.4.9-5   1. Cloud layer optical thickness >    3 K          1.5 K     
          0.1(TBR)                                                      

40.4.9-6   2.  Cloud layer optical thickness     6 K          (TBD)     
          0.1 (TBR)                                                     

40.4.9-7  f.  Measurement Precision              1.5 K        0.5 K     

40.4.9-8  g.  Long Term Stability                1 K          0.1 K     

40.4.9-9  h.  Mapping Uncertainty                4 km         1 km      

40.4.9-10 i.  Maximum Local Average Revisit      6 hrs        6 hrs     
          Time                                                          

40.4.9-11 j.  Maximum Local Refresh              (TBD)        (TBD)     



40.5 Earth Radiation Budget EDRs

All requirements for Earth Radiation Budget EDRs below apply only under both clear and cloudy conditions except for the Surface Albedo.

40.5.1 Absorbed Solar Radiation (IORD Name: Net Shortwave Radiation) (DOC)

Absorbed solar radiation is the difference between the incoming solar radiation flux (all wavelengths) at the top of the atmosphere and the outgoing reflected flux (all wavelengths) at the top of the atmosphere. This parameter is sometimes called "net shortwave radiation (TOA)" since solar radiation is mainly contained in the 0.3 - 4 µm band. This is an instantaneous, not a time-averaged, measurement.(TBR)

Units: W/m2


Para.                                    Thresholds      Objectives      
No.                                                                      

40.5.1-1 a.  Horizontal Cell Size        100 km          20 km           

40.5.1-2 b.  Horizontal Reporting        (TBD)           (TBD)           
         Interval                                                        

40.5.1-3 c.  Horizontal Coverage         Global          Global          

40.5.1-4 d.  Measurement Range           0 - 900 W/m2    0 - 900 W/m2    

40.5.1-5 e.  Measurement Accuracy        5 W/m2          2.5 W/m2        

40.5.1-6 f.  Measurement Precision       3 W/m2          1.5 W/m2        

40.5.1-7 g. Mapping Uncertainty          10 km           5 km            

40.5.1-8 h.  Maximum Local Average       12 hrs          8 hrs           
         Revisit Time                                                    

40.5.1-9 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.5.2 Albedo (Surface)

Surface albedo is defined as the amount of visible solar radiation (0.4 - 0.7 µm) reflected by the earth's surface into a hemisphere divided by the amount incident.(TBR) This EDR is required during daytime only and under clear conditions only This is an instantaneous, not a time-averaged, measurement. (TBR)

Units: Dimensionless


Para.                                    Thresholds      Objectives      
No.                                                                      

40.5.2-1  a.  Horizontal Cell Size       4 km            0.5 km          

40.5.2-2  b.  Horizontal Reporting       (TBD)           (TBD)           
          Interval                                                       

40.5.2-3  c . Horizontal Coverage        Global          Global          

40.5.2-4  d.  Measurement Range          0 - 1.0         0 - 1.0         

40.5.2-5  e.  Measurement Accuracy       0.05            0.0125          

40.5.2-6  f.  Measurement Precision      0.02            0.01            

40.5.2-7  g.  Long Term Stability        0.02            0.01            

40.5.2-8  h.  Mapping Uncertainty        4 km            1.0 km          

40.5.2-9  i.  Maximum Local Average      24 hrs          4 hrs           
          Revisit Time                                                   

40.5.2-10 j.  Maximum Local Refresh      (TBD)           (TBD)           



40.5.3 Downward Longwave Radiation (Surface) (DOC)

Downward longwave radiation (surface) is defined as the irradiance in the 4 - 50 µm wavelength band incident downward at the surface of the earth. Physical measurements are not required in the entire 4 - 50 µm band as long as the reported value meets the accuracy requirement specified below. This is an instantaneous, not a time-averaged, measurement. (TBR)

Units: W/m2


Para.                                    Thresholds      Objectives      
No.                                                                      

40.5.3-1 a.  Horizontal Cell Size        40 km @ nadir   10 km           

40.5.3-2 b.  Horizontal Reporting        (TBD)           (TBD)           
         Interval                                                        

40.5.3-3 c.  Horizontal Coverage         Global          Global          

40.5.3-4 d.  Measurement Range           0 - 500 W/m2    0 - 500 W/m2    

40.5.3-5 e.  Measurement Accuracy        15 W/m2 (TBR)   1 W/m2          

40.5.3-6 f.  Measurement Precision       0.1 W/m2        0.1 W/m2        

40.5.3-7 g.  Mapping Uncertainty         10 km           (TBD)           

40.5.3-8 h.  Maximum Local Average       14 hrs          6 hrs           
         Revisit Time                                                    

40.5.3-9 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.5.4 Downward Shortwave Radiation (Surface) (IORD Name: Insolation) (DOC)

Downward shortwave radiation (surface) is defined as the irradiance at wavelengths less than 4 µm incident downward at the surface of the earth. This is an instantaneous, not a time-averaged, measurement. (TBR)

Units: W/m2


Para.                                    Thresholds      Objectives      
No.                                                                      

40.5.4-1 a.  Horizontal Cell Size        50 km           100 km (TBR)    

40.5.4-2 b.  Horizontal Reporting        (TBD)           (TBD)           
         Interval                                                        

40.5.4-3 c.  Horizontal Coverage         Global          Global          

40.5.4-4 d.  Measurement Range           0 - 1400 W/m2   0 - 1400 W/m2   

40.5.4-5 e.  Measurement Accuracy        20 W/m2         1 W/m2          

40.5.4-6 f.  Measurement Precision       5 W/m2          0.1 W/m2        

40.5.4-7 g.  Mapping Uncertainty         5 km            1 km            

40.5.4-8 h.  Maximum Local Average       24 hrs          24 hrs          
         Revisit Time                                                    

40.5.4-9 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.5.5 Outgoing Longwave Radiation (Top of Atmosphere) (IORD Name: Total Longwave Radiation) (DOC)

Outgoing longwave radiation (top of atmosphere - TOA) is defined as the outgoing (upward) flux of longwave radiation (4 - 50 µm) at the top of the atmosphere. This is an instantaneous, not a time-averaged, measurement. (TBR)

Units: W/m2


Para.                                    Thresholds      Objectives      
No.                                                                      

40.5.5-1 a.  Horizontal Cell Size        100 km          20 km           

40.5.5-2 b.  Horizontal Reporting        (TBD)           (TBD)           
         Interval                                                        

40.5.5-3 c.  Horizontal Coverage         Global          Global          

40.5.5-4 d.  Measurement Range           0 - 500 W/m2    0 - 500 W/m2    

40.5.5-5 e.  Measurement Accuracy        5 W/m2          2.5 W/m2        

40.5.5-6 f.  Measurement Precision       3 W/m2          1.5 W/m2        

40.5.5-7 g. Mapping Uncertainty          10 km           5 km            

40.5.5-8 h.  Maximum Local Average       24 hours        4 hr            
         Revisit Time                    (once/daytime                   
                                         &                               
                                         once/nighttime)                 

40.5.5-9 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.5.6 Solar Irradiance (DOC)

Solar irradiance is the radiated power incident on a surface orthogonal to the line of sight to the sun from the location of the spacecraft. The total irradiance (all wavelengths) and the irradiance in two narrow bands, one in the visible spectrum (0.2 - 0.3 µm) and one in the near infrared (centered at 1.5 µm), are to be reported.

Units: W/m2


Para.                                 Thresholds         Objectives       
No.                                                                       

          a.  Measurement Range                                           

40.5.6-1   1. Total                   1320 - 1420 W/m2   1320 - 1420      
                                                         W/m2             

40.5.6-2   2. 0.2 - 0.3 µm            0 - 10 W/m2        0 - 10 W/m2      

40.5.6-3   3. 1.5 µm narrow band      0 - 10 W/m2        0 - 10 W/m2      

          b.  Measurement                                                 
          Uncertainty (TBR)                                               

40.5.6-4   1. Total                   1.5 W/m2           0.5 W/m2         

40.5.6-5   2. 0.2 - 0.3 µm            2 %                0.5 %            

40.5.6-6   3. 1.5 µm narrow band      2 %                0.5 %            

          c.  Long Term Stability                                         
          (TBR)                                                           

40.5.6-7   1. Total                   0.002 %/yr         0.0005 %/yr      

40.5.6-8   2. 0.2 - 0.3 µm            0.02 %/yr          0.01 %/yr        

40.5.6-9   3. 1.5 µm narrow band      0.01 %/yr          0.005 %/yr       

40.5.6-10 d.  Reporting Frequency     20 min of viewing  20 min of        
                                      sun per orbit,     viewing sun per  
                                      one satellite      orbit, for each  
                                                         of three         
                                                         satellites       



40.6 Land EDRs

40.6.1 Land Surface Temperature

Land surface temperature (LST) is defined as the skin temperature of the uppermost layer of the land surface. This EDR is required under clear conditions only.

Units: K


Para.                                    Thresholds      Objectives      
No.                                                                      

40.6.1-1 a.  Horizontal Cell Size        4 km            1 km            

40.6.1-2 b.  Horizontal Reporting        (TBD)           (TBD)           
         Interval                                                        

40.6.1-3 c.  Horizontal Coverage         Land            Land            

40.6.1-4 d.  Measurement Range           213 K - 343 K   213 K - 343 K   

40.6.1-5 e.  Measurement Accuracy        2.5 K           1 K             

40.6.1-6 f.  Measurement Precision       0.5 K           0.025 K         

40.6.1-7 g.  Mapping Uncertainty         4 km            1 km            

40.6.1-8 h.  Maximum Local Average       6 hrs           3 hrs           
         Revisit Time                                                    

40.6.1-9 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.6.2 Normalized Difference Vegetation Index (NDVI) (TBR)

Normalized difference vegetation index is most directly related to absorption of photosynthetically active radiation, but is often correlated with biomass or primary productivity. Red spectral measurements are sensitive to the chlorophyll content of vegetation and the near IR to the mesophyll structure of leaves. The normalized ratio (IR-Red)/(IR+ Red) has a close relationship with the photosynthetic capacity of specific vegetation types. The NASA/NOAA NDVI (for AVHRR-3) is defined as follows:

NDVI = RATIO of [(Reflectance band 2 - reflectance band 1)/ sum],

where: Band 2 = NIR band(0.72-1.0 microns);

Band 1 = VIS band(0.572-0.703 microns).

These specific spectral ranges are not required. The requirements below apply only under clear conditions.

Units: dimensionless


Para.                                   Thresholds       Objectives      
No.                                                                      

40.6.2-1  a.  Horizontal Cell Size      4 km             1 km            

40.6.2-2  b.  Horizontal Reporting      (TBD)            (TBD)           
          Interval                                                       

40.6.2-3  c.  Horizontal Coverage       Land             (TBD)           

40.6.2-4  d.  Measurement Range         -1 to +1 NDVI    -1 to +1        
                                        units                            

40.6.2-5  e.  Measurement Accuracy      0.05 NDVI units  0.03 NDVI       
                                                         units           

40.6.2-6  f.  Measurement Precision     0.04 NDVI units  0.02 NDVI       
                                                         units           

40.6.2-7  g.  Long Term Stability       0.04 NDVI units  0.04 NDVI       
                                                         units           

40.6.2-8  h. Mapping Uncertainty        4 km             1 km            

40.6.2-9  i.  Maximum Local Average     24 hrs           24 hrs          
          Revisit Time                                                   

40.6.2-10 j.  Maximum Local Refresh     (TBD)            (TBD)           



40.6.3 Snow Cover/Depth

Horizontal and vertical extent of snow cover. As a threshold, only fraction of snow cover in the specified horizontal cell (clear or cloudy) is required, regardless of depth. As an objective, fraction of snow cover for snow having a specified minimum depth is required in the specified horizontal cell (clear or cloudy) for a set of specified minimum depths.


Para.                                    Thresholds      Objectives        
No.                                                                        

         a.  Horizontal Cell Size (TBR)                                    
                                                                           

40.6.3-1  1. Clear - daytime             1.3 km          1 km              

40.6.3-2  2. Cloudy and/or nighttime     12.5 km         1 km              

40.6.3-3 b.  Horizontal Reporting        (TBD)           (TBD)             
         Interval                                                          

40.6.3-4 c.  Snow Depth Ranges           > 0 cm (Any     > 8 cm, > 15 cm,  
                                         Snow            > 30 cm, >51 cm,  
                                         Thickness)      >76 cm            

40.6.3-5 d.  Horizontal Coverage         Land            Land & Ice        

40.6.3-6 e.  Vertical Coverage           0 - 40 cm       0 - 1 m           

40.6.3-7 f.  Measurement Range           0 - 1           0 - 1 per snow    
                                                         depth category    

         g.  Measurement                                                   
         Uncertainty(TBR)                                                  

40.6.3-8  1. Clear - daytime             10% (snow/no    10% for snow      
                                         snow)           depth             

40.6.3-9  2. Cloudy and/or nightime      20% (snow/no                      
                                         snow)           TBD               

         h. Mapping Uncertainty                                            

40.6.3-1  1. Clear                       2 km            1 km              
0                                                                          

40.6.3-1  2. Cloudy                      7 km            1 km              
1                                                                          

40.6.3-1 i.  Maximum Local Average       12 hrs          3 hrs             
2        Revisit Time                                                      

40.6.3-1 j.  Maximum Local Refresh       (TBD)           (TBD)             
3                                                                          



40.6.4 Vegetation Index/Surface Type

Vegetation index/surface type is defined as the predominant vegetation and/or soil type in a given area.

Each given area shall be classified as one of the following 21 types: crop land, brush/scrub, coniferous forest, deciduous forest, tropical forest, grass land, swamp, marsh/bog, flooded land, loam, sandy soil, clay, peat, gravel, desert, water, snow/ice, urban/developed, rocky fields, tundra, and Savannah. Estimation of the percentage of vegetation cover per type in each cell is an objective. The requirements below apply under both clear and cloudy conditions.

Units:

Type: N/A

Vegetation Cover: per cent


Para.                                     Thresholds      Objectives      
No.                                                                       

          a.  Horizontal Cell Size                                        

40.6.4-1   1. Global                      20 km           1 km            

40.6.4-2   2. Regional                    20 km           0.25 km         

40.6.4-3  b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

          c.  Horizontal Coverage                                         

40.6.4-4   1.  Global                     Land            Land            

40.6.4-5   2.  Regional                   Land, up to     Land, up to     
                                          1/2 orbit,      1/2 orbit,      
                                          non-contiguous, non-contiguous, 
                                           commandable     commandable    
                                          by SOC          by SOC          

          d.  Measurement Range                                           

40.6.4-6   1. Vegetation/surface type     21 types        21 types        
                                          specified       specified       
                                          above           above           

40.6.4-7   2.  Vegetation cover           N/A             0 - 100 %       

40.6.4-8  e.  Measurement Accuracy (veg.  N/A             2 %             
          cover)                                                          

40.6.4-9  f.  Measurement Precision       N/A             0.1 %           
          (veg. cover)                                                    

40.6.4-10 g.  Correct Typing Probability  70 %            (TBD)           
          (vegetation /surface type)                                      

40.6.4-11 h.  Mapping Uncertainty         5 km            1 km            

40.6.4-12 i.  Maximum Local Average       24 hrs          3 hrs           
          Revisit Time                                                    

40.6.4-13 j.  Maximum Local Refresh       (TBD)           (TBD)           



40.7 Ocean/Water EDRs

40.7.1 Currents (DoD-coastal; DOC-surface)

Ocean currents are defined as large-scale movements of the surface and near-surface waters of the ocean driven by wind and the distribution of water density. Currents are described by a local vector field specifying water speed and direction at each point. "Coastal" is defined to be within 370km of the coastline. The requirements below apply only under clear conditions.

Units:

Speed: m/s

Direction: deg from north


Para.                                   Thresholds      Objectives      
No.                                                                     

          a.  Horizontal Cell Size                                      

40.7.1-1   1. Global                    4 km            1 km            

40.7.1-2   2. Regional (Coastal)        1.3 km          0.25 km         

40.7.1-3  b.  Horizontal Reporting      (TBD)           (TBD)           
          Interval                                                      

40.7.1-4  c.  Vertical Cell Size(TBR)   5 m             1 m             

40.7.1-5  d.  Vertical Reporting        Vertical Cell   Vertical Cell   
          Interval                      Size            Size            

          e.  Horizontal Coverage       Oceans          Oceans          

40.7.1-6   1. Global                    Oceans, > 370   Oceans, > 370   
                                        km from         km from         
                                        coastline       coastline       

40.7.1-7   2. Regional (Coastal)        Oceans, < 370   Oceans, < 370   
                                        km from         km from         
                                        coastline       coastline       

40.7.1-8  f.  Vertical Coverage         0 to -10 m      0 to -30 m      

          g.  Measurement Range                                         

40.7.1-9   1. Speed                     0 - 5 m/s       0 - 5 m/s       

40.7.1-10  2. Direction                 0 - 360 deg     0 - 360 deg     

          h.  Measurement                                               
          Accuracy(TBR)                                                 

40.7.1-11   1. Speed                    0.25 m/s        0.1 m/s         

40.7.1-12  2. Direction                 15 deg          5 deg           

          i.  Measurement                                               
          Precision(TBR)                                                

40.7.1-13  1. Speed                     0.25 m/s        0.1 m/s         

40.7.1-14  2. Direction                 15 deg          5 deg           

40.7.1-15 j. Mapping Uncertainty        3 km            1 km            

40.7.1-16 k.  Maximum Local Average      (TBD)          12 hrs          
          Revisit Time                                                  

40.7.1-17 l.  Maximum Local Refresh     (TBD)           (TBD)           



40.7.2 Fresh Water Ice

Fresh water ice concentration is defined as the fraction of a given area of fresh water that is covered by ice, quantized to the nearest one tenth. Ice edge boundary is the contour separating fresh water from fresh water ice. The error in ice edge boundary location is defined as the distance between a measured boundary point and the nearest point on the true ice edge boundary. The measurement uncertainty requirement on ice edge boundary limits this error. Ice edge concentration and boundaries are derived from the Imagery EDR. The requirements below apply only under clear conditions.

Units:

Concentration: Dimensionless

Ice Edge Boundary: lat/long


Para.                                  Thresholds       Objectives      
No.                                                                     

          a.  Horizontal Cell Size                                      

40.7.2-1       1.  Regional, nadir      4 times 0.4 km       (TBD)      
                                            (TBR)                       

40.7.2-2       2.  Regional, worst      4 times 0.8 km   4 times 0.65   
          case                              (TBR)          km (TBR)     

40.7.2-3  b.  Horizontal Reporting     (TBD)            (TBD)           
          Interval                                                      

40.7.2-4  c.  Horizontal Coverage      Fresh Water      Fresh Water     
                                       Up to 1/2        Up to 1/2       
                                       orbit,           orbit,          
                                       non-contiguous,  non-contiguous, 
                                       commandable by    commandable    
                                       SOC              by SOC          

40.7.2-5  d.  Measurement Range        1/10 to 10/10    0/10 to 10/10   
                                       concentration    concentration   

          e.  Measurement Uncertainty                                   

40.7.2-6       1. Ice Edge             10 km            5 km            
          Boundary(TBS)                                                 

40.7.2-7       2. Ice Concentration    20 % or 1/10     10 %            

40.7.2-8  f.  Mapping Uncertainty      3 km             1 km            

40.7.2-9  g.  Maximum Local Average    12hrs            6hrs            
          Revisit Time                                                  

40.7.2-10 h.  Maximum Local Refresh    (TBD)            (TBD)           



40.7.3 Ice Surface Temperature

As a threshold, the temperature of the surface of ice over land or water is required. The objective is to measure the atmospheric temperature 2 m above the surface of the ice. This EDR is required under clear conditions only.

Units: K


Para.                                  Thresholds      Objectives      
No.                                                                    

40.7.3-1 a.  Horizontal Cell Size      30km            10km            

40.7.3-2 b.  Horizontal Reporting      (TBD)           (TBD)           
         Interval                                                      

40.7.3-3 c.  Horizontal Coverage       Ice-covered     Ice-covered     
                                       land/water      land/water      

40.7.3-4 d.  Measurement Range         213 K - 293 K    (TBD)          

40.7.3-5 e.  Measurement Uncertainty   1 K              (TBD)          

40.7.3-6 f.  Mapping Uncertainty       3 km            1 km            

40.7.3-7 g.  Maximum Local Average     24 hrs          12 hrs          
         Revisit Time                                                  

40.7.3-8 h.  Maximum Local Refresh     (TBD)           (TBD)           



40.7.4 Littoral Sediment Transport

Littoral sediment transport is defined as the transport of sediment by river systems and along shore ocean currents. More specifically, for each cell on the earth's surface overlying water-covered sediment, littoral sediment transport is defined as the change in the volume of sediment in the cell since the last measurement divided by the time interval between measurements. This EDR is required under clear and daytime conditions only.

Units: m3/day


Para.                                  Thresholds      Objectives      
No.                                                                    

40.7.4-1 a.  Horizontal Cell Size      1.3 km (TBR)    0.1 km (TBR)    

40.7.4-2 b.  Horizontal Reporting      (TBD)           (TBD)           
         Interval                                                      

40.7.4-3 c.  Horizontal Coverage       Rivers, ocean   Rivers, ocean   
                                       coastal         coastal         
                                       regions         regions         

40.7.4-4 d.  Measurement Range         (TBD)           (TBD)           

40.7.4-5 e.  Measurement Accuracy      greater of 30   greater of 15   
                                       % and (TBD)     % and (TBD)     

40.7.4-6 f.  Measurement Precision     greater of 40   greater of 15   
                                       % and (TBD)     % and (TBD)     

40.7.4-7 g.  Mapping Uncertainty       3 km            0.1 km          

40.7.4-8 h.  Maximum Local Average     48 hrs          12 hrs          
         Revisit Time                                                  

40.7.4-9 i.  Maximum Local Refresh     (TBD)           (TBD)           



40.7.5 Net Heat Flux

Net heat flux refers to net surface flux over oceans.

Components are longwave and shortwave radiation, latent heat flux and sensible heat flux. The requirements below apply under both clear and cloudy conditions.

Units: W/m2


Para.                                  Thresholds      Objectives      
No.                                                                    

40.7.5-1 a.  Horizontal Cell Size      20 km           5 km            

40.7.5-2 b.  Horizontal Reporting      (TBD)           (TBD)           
         Interval                                                      

40.7.5-3 c.  Horizontal Coverage       Oceans          Oceans          

40.7.5-4 d.  Measurement Range         0 - 1000 W/m2   0 - 2000 W/m2   

40.7.5-5 e.  Measurement Accuracy      10 W/m2         1 W/m2          

40.7.5-6 f.  Measurement Precision     5 W/m2          1 W/m2          

40.7.5-7 g.  Mapping Uncertainty       7 km            (TBD)           

40.7.5-8 h.  Maximum Local Average     6 hrs           3 hrs           
         Revisit Time                                                  

40.7.5-9 i.  Maximum Local Refresh     (TBD)           (TBD)           



40.7.6 Ocean Color/Chlorophyll

The required data product is the concentration of chlorophyll in a vertical column of the ocean, and the requirements below apply to this product. Ocean color, as measured by the radiance reflected by the ocean in a number of narrow visible bands, is typically used to infer chlorophyll concentration. This EDR is required under clear, daytime conditions only.

Units: mg/m3


Para.                                    Thresholds      Objectives      
No.                                                                      

          a. Horizontal Cell Size                                        

40.7.6-1   1. Global, worst case         2.6 km          1 km            

40.7.6-2   2. Regional (Coastal), worst  1.3 km          0.1 km          
          case                                                           

40.7.6-3  b.  Horizontal Reporting       (TBD)           (TBD)           
          Interval                                                       

          c.  Horizontal Coverage        Oceans          Oceans          

40.7.6-4   1. Global                     > 370 km from   > 370 km from   
                                         coastline       coastline       

40.7.6-5   2. Regional (Coastal)         < 370 km from   < 370 km from   
                                         coastline       coastline       

40.7.6-6  d.  Measurement Range          0.05 - 50       0 - 100 mg/m3   
                                         mg/m3                           

40.7.6-7  e.  Measurement Accuracy       The > of 30 %   The > of 30 %   
                                         or TBD mg/m3    or TBD mg/m3    

40.7.6-8  f.  Measurement Precision      The > of 20 %   The > of 10 %   
                                         or TBD mg/m3    or TBD mg/m3    

          g.  Mapping Uncertainty                                        

40.7.6-9   1. Global                     3 km            0.5 km          

40.7.6-10  2. Regional                   3 km            0.1 km          

40.7.6-11 h.  Maximum Local Average      48 hrs          12 hrs          
          Revisit Time                                                   

40.7.6-12 i.  Maximum Local Refresh      (TBD)           (TBD)           



40.7.7 Ocean Wave Characteristics (TBR)

Ocean wave characteristics are defined as the significant wave height and direction of ocean waves. The requirements below apply under both clear and cloudy conditions.

Units:

Height: m

Direction: Degrees from north


Para.                                     Thresholds      Objectives      
No.                                                                       

          a. Horizontal Cell Size                                         

40.7.7-1   1. Global, at nadir, along     20 km           5 km            
          track                                                           

40.7.7-2   2. Global, at nadir, cross     20 km           (TBD)           
          track                                                           

40.7.7-3   3. Regional, at nadir, along    10 km          0.25 km         
          track                                                           

40.7.7-4   4. Regional, at nadir, cross   (TBD)           (TBD)           
          track                                                           

40.7.7-5  b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

40.7.7-6  c.  Horizontal Coverage         Oceans          Oceans          

          d.  Measurement Range                                           

40.7.7-7   1. Height                      0.5 - 30 m      0.5 - 30 m      

40.7.7-8   2. Direction                   0 - 360 deg     0 - 360 deg     

          e.  Measurement Accuracy                                        

40.7.7-9   1. Height                      0.2 m           0.2 m           

40.7.7-10  2. Direction                   10 deg          5 deg           

          f.  Measurement Precision                                       

40.7.7-11  1. Height                      0.2 m           0.1 m           

40.7.7-12  2. Direction                   10 deg          5 deg           

          g.  Mapping Uncertainty                                         

40.7.7-13  1. Global, worst case          10  km          2 km            

40.7.7-14  2. Regional, worst case        4  km           0.25 km         

40.7.7-15 h.  Maximum Local Average       14 days         6 hrs           
          Revisit Time                                                    

40.7.7-16 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.7.8 Sea Ice Age and Sea Ice Edge Motion

Sea ice age is defined as the time that has passed since the formation of the surface layer of an ice covered region of the ocean. The content of the sea ice age EDR is the typing of areas of sea ice by age. Sea ice motion is defined as the displacement of a sea ice edge. The requirements below apply under both clear and cloudy conditions.

Units:

Ice age: Class

Ice edge motion: km/day


Para.                                     Thresholds      Objectives      
No.                                                                       

40.7.8-1  a.  Horizontal Cell Size (Ice   3 km            0.1 km          
          Age)                                                            

40.7.8-2  b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

40.7.8-3  c.  Horizontal Coverage         Oceans          Oceans          

          d.  Measurement Range                                           

40.7.8-4   1. Ice Age Classes                                             
                                          First Year,     New, Young,     
                                          Multi-year      First Year,     
                                          (TBR)           and Old (TBR)   

40.7.8-5   2. Ice Motion                  0-50 km/day     0 - 50 km/day   

40.7.8-6  e.  Probability of Correct      70 %            90 %            
          Typing (Ice Age)                                                

40.7.8-7  f.  Measurement Uncertainty     1 km/day        0.1 km/day      
          (Ice motion)                                                    

40.7.8-8  g.  Mapping Uncertainty         3 km            1 km            

40.7.8-9  h.  Maximum Local Average       24 hrs          12 hrs          
          Revisit Time                                                    

40.7.8-10 i.  Maximum Local Refresh       (TBD)           (TBD)           



40.7.9 Sea Surface Height

Sea surface height is defined as the longwave (> (TBD) km) horizontal variations in the height of the sea surface with respect to the geoid. The requirements below apply under both clear and cloudy conditions.

Units: m


Para.                                      Thresholds     Objectives      
No.                                                                       

40.7.9-1 a.  Horizontal Cell Size ( at     10 km          0.5 km          
         nadir along track)                                               

40.7.9-2 b.  Horizontal Reporting          (TBD)          (TBD)           
         Interval                                                         

40.7.9-3 c.  Horizontal Coverage           Oceans         Oceans          

40.7.9-4 d.  Measurement Range             -50 to +50 m   -50 to +50 m    

40.7.9-5 e.  Measurement Accuracy          5 cm           3 cm            

40.7.9-6 f.  Measurement Precision         3 cm           2 cm            

40.7.9-7 g.  Mapping Uncertainty           2 km           1 km            

40.7.9-8 h.  Maximum Local Average         14 days        3 hr            
         Revisit Time                                                     

40.7.9-9 i.  Maximum Local Refresh         (TBD)          (TBD)           



40.7.10 Surface Wind Stress (DOC) (TBR)

Surface wind stress is defined as magnitude of the frictional stress of the wind acting on the sea surface, causing it to move as a wind-drift current, and causing the formation of waves. The requirements below apply under both clear and cloudy conditions.

Units: N/m2


Para.                                      Thresholds     Objectives      
No.                                                                       

40.7.10-1 a.  Horizontal Cell Size         50 km          20 km           

40.7.10-2 b.  Horizontal Reporting         (TBD)          (TBD)           
          Interval                                                        

40.7.10-3 c.  Horizontal Coverage          Oceans         Oceans          

40.7.10-4 d.  Measurement Range            0 - 50 N/m2    0 - 50 N/m2     
                                           (TBR)                          

40.7.10-5 e.  Measurement Accuracy         2 N/m2         1 N/m2          

40.7.10-6 f.  Measurement Precision        2 N/m2         1 N/m2          

40.7.10-7 g. Mapping Uncertainty           7 km           1 km            

40.7.10-8 h.  Maximum Local Average        12 hrs         12 hr           
          Revisit Time                                                    

40.7.10-9 i.  Maximum Local Refresh        (TBD)          (TBD)           



40.7.11 Mass Loading (TBR) (IORD Title - Turbidity)

Mass Loadingis defined as the concentration of suspended matter in a vertical column in the ocean. This quantity is refered to as "turbidity" in the IORD because it is used to derive both rates of sediment deposition and optical clarity. The depth of the vertical column is specified by the vertical cell size. Turbidity may be derived from ocean color data. The requirements below apply only under clear conditions.

Units: mg/l


Para.                                     Thresholds      Objectives      
No.                                                                       

40.7.11-1 a.  Horizontal Cell Size        1.3 km          0.25 km         

40.7.11-2 b.  Horizontal Reporting        (TBD)           (TBD)           
          Interval                                                        

40.7.11-3 c.  Horizontal Coverage         Oceans          Oceans          

40.7.11-4 d.  Vertical Cell Size          Surface layer   (TBD)           
                                          ((TBD) m)                       

40.7.11-5 e.  Measurement Range           (TBD)           0 - 100 mg/l    

40.7.11-6 f.  Measurement Accuracy        greater of 30   0.1 mg/l        
                                          % and (TBD)                     

40.7.11-7 g.  Measurement Precision       (TBD)           0.1 mg/l        

40.7.11-8 h. Mapping Uncertainty          (TBD)           0.5 km          

40.7.11-9 i.  Maximum Local Average       48 hrs          24 hrs          
          Revisit Time                                                    

40.7.11-1 j.  Maximum Local Refresh       (TBD)           (TBD)           
0                                                                         



40.8 Space Environmental EDRs (TBR)

40.8.1 Auroral Boundary

The auroral boundaries are the edges (both equatorward and poleward) of the auroral zones. A more precise definition of these boundaries can only be formulated within the context of the measurement technique involved. The locations of the auroral boundaries, which change as a function of geomagnetic activity, are required as input to magnetospheric and ionospheric models at 50WS. Of greatest (but not sole) importance is the latitude of the equatorward boundary at midnight. Knowledge of auroral boundaries contributes in a minor sense to satisfaction of the Ionospheric Scintillation EDR (EDR 40.8.11), since the location of the auroral oval constrains the occurrence of scintillation phenomena at high latitudes.

Units: degrees latitude and longitude


Para.                                     Thresholds      Objectives      
No.                                                                       

40.8.1-1  a. Horizontal Reporting         N/A             10 km along     
          Interval                                        boundary (TBR)  

40.8.1-2  b. Horizontal Coverage          (TBS)           (TBS)           

          c. Measurement Range                                            

40.8.1-3   1. Latitude                    Abs. value >    Abs. value >    
                                          40 deg          40 deg          

40.8.1-4   2. Longitude                   0 - 360 deg     0 - 360 deg     

40.8.1-5  d. Measurement Uncertainty      50 km           10 km           

40.8.1-6  e. Reporting Frequency (for     (TBS)           (TBS)           
          in-track derived boundary)                                      

40.8.1-7  f. Maximum Local Average        (TBS)           (TBS)           
          Revisit Time (for imagery                                       
          derived boundary)                                               



40.8.2 Total Auroral Energy Deposition

An estimate of the total (global average) upper atmospheric auroral heat input due to particle precipitation. Contributions due to precipitating electrons and ions must be separately determined. Total Auroral Energy Deposition is an input to upper atmospheric density models. A change in energy deposition of 10-4 W/m2 is consistent with a change in upper atmospheric temperature of 15 degrees.

Units: watts/m2


Para.                                  Thresholds      Objectives        
No.                                                                      

40.8.2-1  a. Horizontal Coverage       Auroral Zones   Auroral Zones     

          b. Measurement Range                                           

40.8.2-2   1. Electrons                10-4 - 1 W/m2   5 x 10-5 - 1      
                                                       W/m2              

40.8.2-3   2. Ions                     10-4 - 0.1      5 x 10-5 - 0.1    
                                       W/m2            W/m2              

40.8.2-4  c. Measurement Uncertainty   greater of      greater of        
                                       10-4  W/m2 or   5x10-5  W/m2 or   
                                       20 %            10 %              

40.8.2-5  d. Reporting Frequency       (TBS)           (TBS)             



40.8.3 Auroral Imagery

Two-dimensional (along/cross track) images of the Earth's auroral regions, taken in one or more of several wavelength intervals in the infrared, visible, far ultraviolet (FUV), and x-ray portions of the spectrum. The table below gives some information on requirements for the far-ultraviolet; requirements for other spectral ranges are TBR. This imagery can provide information on the location of the Auroral Boundary (EDR 40.8.1) and regions of enhanced auroral activity, and can be used to infer characteristics of precipitating particles.

Units:

Wavelength: nm

For visible/IR imagery: watts/m2

For FUV imagery: rayleighs

For x-ray imagery: (TBD)


Para.                                    Thresholds      Objectives       
No.                                                                       

40.8.3-1 a. Horizontal Cell Size         20 km           10 km            

40.8.3-2 b. Horizontal Reporting         Local           Local            
         Interval                        Horizontal      Horizontal Cell  
                                         Cell Size       Size             

40.8.3-3 c. Horizontal Coverage          (TBS)           Auroral Zones    

40.8.3-4  d. Measurement Range           120-180 nm      80-250 nm (TBR)  
                                         (TBR)                            

40.8.3-5 e. Measurement Uncertainty      10%             5%.              

40.8.3-6 f. Mapping Uncertainty          20 km           10 km            

40.8.3-7 g. Maximum Local Average        (TBS)           (TBS)            
         Revisit Time                                                     



40.8.4 Electric Fields

Electric fields in the ionosphere cause transport of plasma and at high latitudes provide a "footprint" of the magnetospheric fields. Thus, electric fields are required inputs for both ionospheric and magnetospheric specification models. Electric fields are also needed to determine the amount of joule heating in the auroral region, which is an input to neutral atmospheric models. Electric fields are three-component vector quantities.

Units: mv/meter


Para.                                  Thresholds      Objectives      
No.                                                                    

40.8.4-1 a. Horizontal Reporting       (TBR)           (TBS)           
         Interval                                                      

40.8.4-2 b. Horizontal Coverage        In-track        In-track        

40.8.4-3 c. Measurement Range          0-150 mv/meter  0-250 mv/meter  

40.8.4-4 d. Measurement Uncertainty    3.0 mv/meter    0.1 mv/meter    

40.8.4-5 e. Measurement Precision      2.0 mv/meter    0.1 mv/meter    

40.8.4-6 f. Local Time Range           (TBS)           (TBS)           



40.8.5 Electron Density Profiles/Ionospheric Specification

The ionosphere is that portion of the Earth's upper atmosphere which is composed of electrically charged particles (electrons and various ions). A complete vertical electron density profile would extend from the D and E regions at altitudes between 60 and 150 km, through the F region within which the electron density reaches a maximum value nominally between altitudes of 250-350 km, through the topside up to 3,000 km, and into the plasmasphere. The Air Force requires global ionospheric specification to meet a number of operational needs. Electron density profile measurements, to include measurements of various important parameters associated with a complete profile, are required as inputs to and to augment the outputs of operational ionospheric models. Profile measurements above the NPOESS altitude are not required. The term TEC in the following table refers to the Total Electron Content associated with a complete vertical profile, ground to 36,000 km altitude, unless otherwise indicated.

Units:

NmF2 /electron density: cm-3

HmF2: km

TEC: 1016/m2 = 1 TEC unit


Para.                                   Thresholds      Objectives      
No.                                                                     

40.8.5-1  a. Horizontal Reporting       Horizontal      Horizontal      
          Interval                      Cell Size       Cell Size       

40.8.5-2  b. Vertical Reporting         Vertical Cell   Vertical Cell   
          Interval                      Size            Size            
          (profiles only, below NPOESS                                  
          altitude)                                                     

          c. Horizontal Cell Size                                       

40.8.5-3   1. 0-30° latitude            200 km          100 km          

40.8.5-4   2. 30-50° latitude           500 km          250 km          

40.8.5-5   3. 50-90° latitude           100 km          50 km           

40.8.5-6  d. Vertical Cell Size (for    10 km within    5 km            
          profiles)                     100 km of E/F                   
                                        peaks, 20 km                    
                                        elsewhere                       

40.8.5-7  e. Horizontal Coverage        (TBS)           (TBS)           

40.8.5-8  f. Vertical Coverage          90-800 km       50-2000 km      

          g. Measurement Range                                          

40.8.5-9   1. Density at an arbitrary   3x105-107 cm-3  104-107 cm-3    
          altitude below NPOESS (local                                  
          density)                                                      

40.8.5-10  2. TEC                       3-200 TEC       1-200 TEC       
                                        units           units           

40.8.5-11  3. foF2                      5 to 30 MHz     1 to 30 MHz     

          h. Measurement Uncertainty                                    

40.8.5-12  1. Density at an arbitrary   20% or 3 x105   greater of 5%   
          altitude below NPOESS         cm-3  (TBR)     or 104 cm-3     

40.8.5-13  2. NmF2                      20%             5%              

40.8.5-14  3. TEC                       20% or 3 TEC    1 TEC unit      
                                        units                           

40.8.5-15  4. HmF2                      20 km           5 km            

40.8.5-16  5. NmE                       20% or 3x103    (TBS)           
                                        cm-3                            

40.8.5-17  6. HmE                       10 km (TBR)     (TBS)           

40.8.5-18  7. Topside scale height      20% (TBR)       (TBS)           

40.8.5-19  8. TEC above NPOESS          3 TEC units     (TBS)           

40.8.5-20 i. Maximum Local Average      (TBD)           (TBD)           
          Revisit Time                                                  



40.8.6 Geomagnetic Field

Vector measurements of the earth's magnetic field at NPOESS altitude. There are two uses for this data. First, to determine magnetic field aligned current boundaries as inputs to magnetospheric specification models. Second, as inputs to the World Magnetic Field Model. The latter use requires high accuracy. Because of the difference in accuracy requirements for these two uses, this parameter has two sets of thresholds and objectives (TBS), thresholds specified below are for the higher accuracy requirement).

Units: nanotesla (nT)


Para.                                      Thresholds      Objectives      
No.                                                                        

40.8.6-1 a. Horizontal Reporting Interval  10 km           500 m           

40.8.6-2 b. Horizontal Coverage            In-track        In-track        

40.8.6-3 c. Measurement Range              20,000-60,000   10,000-60,000   
                                           nT              nT (TBR)        

40.8.6-4 d. Measurement Uncertainty        6 nT RMS        2 nT            
         (magnitude)                                                       

40.8.6-5 e. Mapping Uncertainty            100 m SEP       (TBS)           

40.8.6-6 f. Measurement Accuracy of        1.0 arc min     0.6 arc min     
         Vector Direction                                                  

40.8.6-7 g. Measurement Precision          2 nT            0.5 nT          

40.8.6-8 h. Local Time Range               (TBS)           (TBS)           



40.8.7 In-situ Ion Drift Velocity

Measurement of the three dimensional ion drift velocity at NPOESS altitude.

Units: km/sec


Para.                                  Thresholds      Objectives      
No.                                                                    

40.8.7-1 a. Horizontal Reporting       (TBS)           (TBS)           
         Interval                                                      

40.8.7-2 b. Horizontal Coverage        In-track        In-track        

40.8.7-3 c. Measurement Range          0-3 km/sec      0-5 km/sec      

40.8.7-4 d. Measurement Uncertainty    75 m/sec        50 m/sec        

40.8.7-5 e. Measurement Precision      50 m/s          25 m/s          

40.8.7-6 f. Local Time Range           (TBD)           (TBD)           



40.8.8 In-situ Plasma Density

Measurements of the total thermal electron density at NPOESS altitude. Used to improve the accuracy of remotely sensed electron density profiles at altitudes near the NPOESS altitude and as a minor input to ionospheric specification models. Also used to quantitatively assess ionospheric model performance (see EDR 40.8.11). Measurements of ion densities may also be required (TBS).

Units: cm-3


Para.                                  Thresholds       Objectives      
No.                                                                     

40.8.8-1 a. Horizontal Reporting       50 km            10 km           
         Interval                                                       

40.8.8-2 b. Horizontal Coverage        In-track         In-track        

40.8.8-3 c. Measurement Range          5x103-5x106      102-107 cm-3    
                                       cm-3                             

40.8.8-4 d. Measurement Uncertainty    20%              5%              

40.8.8-5 e. Local Time Range           (TBD)            (TBD)           



40.8.9 In-situ Plasma Fluctuations

Measurement of electron density fluctuations at NPOESS altitude. The desired products are the RMS value of dn/n, where n is the local electron density (see EDR 40.8.8), and the spectral index for the fluctuation spectrum, determined for the indicated range of scale sizes. These parameters can be used to derive an estimate of CkL, a height-integrated irregularity strength parameter which is an input to ionospheric scintillation models (see EDR 40.8.11)

Units:

Spectral Index: (TBS)

dn/n: dimensionless


Para.                                   Thresholds      Objectives      
No.                                                                     

40.8.9-1  a. Horizontal Reporting       100 km          5km (TBR)       
          Interval                                                      

40.8.9-2  b. Horizontal Coverage        In-track        In-track        

          c. Measurement Range                                          

40.8.9-3   1. Fluctuation Scale Length  (TBS)           (TBS)           

40.8.9-4    2. Spectral Index           2-5             1-10            

40.8.9-5   3. dn/n                      10-2-1          10-4-1          

          d. Measurement Uncertainty                                    

40.8.9-6   1. Spectral Index            (TBS)           (TBS)           

40.8.9-7   2. dn/n                      (TBS)           (TBS)           

40.8.9-8  e. Local Time Range           (TBS)           (TBS)           



40.8.10 In-situ Plasma Temperatures

Measurement of both the electron and ion temperatures at NPOESS altitude. Temperatures in the mid-latitudes are used to determine electron density scale heights for input to operational ionospheric models (see EDR 40.8.11).

Units: degrees Kelvin (K)


Para.                                   Thresholds      Objectives      
No.                                                                     

40.8.10-1 a. Horizontal Reporting       100 km          10 km           
          Interval                                                      

40.8.10-2 b. Horizontal Coverage        In-track        In-track        

40.8.10-3 c. Measurement Range          500-10,000 K    500-10,000 K    

40.8.10-4 d. Measurement Uncertainty    10%             5%              



40.8.11 Ionospheric Scintillation

Temporal and spatial fluctuations in ionospheric electron density lead to fading or disruption of transionospheric communication and radar signals, a phenomenon known as scintillation. The extent of the effect depends on the relative motion of the ionosphere and the signal source, the frequency of transmission, and the amplitude and spectral characteristics of the ionospheric fluctuations. Direct measurements of scintillation in terms of amplitude and phase fluctuation indices S4 and sigma-ø are required. In addition, knowledge of the location of the auroral boundary (EDR 40.8.1) is required input to operational models of scintillation

Units:

S4: dimensionless

sigma-ø: radians


Para.                                    Thresholds      Objectives      
No.                                                                      

40.8.11-1 a. Horizontal Cell Size        100 km          50 km           

40.8.11-2 b. Horizontal Coverage         (TBS)           (TBS)           

          c. Measurement Range                                           

40.8.11-3  1. S4                         0.1-1.5         (TBS)           

40.8.11-4  2. sigma-ø                    0.1-20 radians  (TBS)           

          d. Measurement Uncertainty                                     

40.8.11-5  1. S4                         0.1             (TBS)           

40.8.11-6  2. sigma-ø                    0.1 radian      (TBS)           

40.8.11-7 e. Local Time Range            (TBS)           (TBS)           



40.8.12 Neutral Density Profiles/Neutral Atmospheric Specification

Measurement of neutral density profiles. Profiles are to be used, along with other geophysical quantities, as inputs to upper atmospheric density models.

Units:

Individual Species (N2, O2, O) Density: cm-3

Total Density: g/cm3


Para. No.                                 Thresholds         Objectives      

40.8.12-1  a. Horizontal Reporting        500 km, in track   50 km           
           Interval                                                          

40.8.12-2  b. Vertical Reporting          Vertical Cell      Vertical Cell   
           Interval                       Size               Size            

40.8.12-3  c. Horizontal Coverage         (TBS)              (TBS)           

40.8.12-4   d. Vertical Cell Size                                            

40.8.12-5       1.  Up to 120 km          10 km              0.5 km          

40.8.12-6       2.  Above 120 km          10 km              3 km            

40.8.12-7   e. Vertical Coverage          100-750 km         90 - 1600km     

           f. Measurement Range                                              

40.8.12-8       1.  Density               3x10-9 to 2x10-19  (TBS)           
                                          g/ cm-3                            

40.8.12-9       2.  Number density        9x104 to 6x1013    (TBS)           
                                          cm-3                               

           g. Measurement Uncertainty                                        

40.8.12-10  1. 100 to 500 km              15%                                

40.8.12-11               2.  > 500 km     20 %                               

40.8.12-12               3.  90 to 500                       5 %             
           km                                                                

40.8.12-13  4. 500-700 km                                    10%             

40.8.12-14  5. 700-1600 km                                   15%             

40.8.12-15 h. Maximum Local Average       (TBS)              (TBS)           
           Revisit Time                                                      



40.8.13 Radiation Belt/Low Energy Solar Particles

Measurements of particles through this energy range are required to serve as inputs to models of the auroral ionosphere, especially Dregion effects (see EDR 40.8.5) and to determine the boundary and extent of the polar cap (EDR 40.8.1) and provide inputs to magnetospheric models. This information is required to assist in the analysis of satellite anomalies involving surface charging and, at the higher energies, deep dielectric charging and radiation damage. Measurements of ions and electrons are required, including energy spectrum information. Particle measurements are required for pitch angles both within the atmospheric loss cone and near local mirroring to determine that portion of the particle population entering the atmosphere.

Units:

Energy: keV or MeV

Flux: m-2sec-1ster-1


Para.                                     Thresholds       Objectives     
No.                                                                       

40.8.13-1 a. Horizontal Reporting         (TBS)            (TBS)          
          Interval                                                        

40.8.13-2 b. Horizontal Coverage          In-track         In-track       

          c. Measurement Range                                            
          (electrons and ions)                                            

40.8.13-3  1. Energy                      30 keV - 10 MeV  (TBS)          
                                          in 8 bands                      

40.8.13-4  2. Flux                        105-1011         (TBS)          

40.8.13-5 d. Pitch Angle Resolution       (TBS)            (TBS)          

40.8.13-6 e. Measurement Precision        5% (TBR)         1% (TBS)       
          (flux)                                                          

40.8.13-7 f. Measurement Accuracy (flux)  20%              10%            

40.8.13-8 g. Number of Platforms          (TBS)            (TBS)          



40.8.14 Solar/Galactic Cosmic Rays

Definition:

Measurements of particles through this energy range are required to serve as inputs to models of the auroral ionosphere, especially Dregion effects (see EDR 40.8.5) and to determine the boundary and extent of the polar cap (EDR 40.8.1). In addition, this information is required to assist in the analysis of satellite anomalies, semiconductor and solar cell radiation damage, and radiation hazard to astronauts and aircraft personnel. Measurements of ion energy spectrum and composition are required. Particle measurements are required for pitch angles both within the atmospheric loss cone and near local mirroring to discriminate that portion of the particle population entering the atmosphere from that which is trapped.

Units:

Energy: MeV/nucleon

Flux: m-2sec-1ster-1


Para.                                       Thresholds      Objectives      
No.                                                                         

40.8.14-1 a. Horizontal Reporting Interval  (TBS)           (TBS)           

40.8.14-2 b. Horizontal Coverage            In-track        In-track        

          c. Measurement Range                                              

40.8.14-3  1. Proton and Alpha Energies     [>10] - [1000]  [>10] -         
                                            in 6 bands      [>1000] in 8    
                                                            bands           

40.8.14-4  2. Heavy Ion (CNO & Fe)          [>10] - [100]   (TBS)           
          Energies                          in 4 bands                      

40.8.14-5  3. Proton Flux                   103-1010        102-1010        

40.8.14-6  4. Alpha Particle Flux           102-108         102-108         

40.8.14-7  5. Heavy Ion (CNO) Flux          100-107         10-2-107        

40.8.14-8  6. Heavy Ion (Fe) Flux           10-1-106        10-3-106        

40.8.14-9 d. Pitch Angle Resolution         (TBS)           (TBS)           

40.8.14-1 e. Measurement Precision (flux)   5% (TBS)        1% (TBS)        
0                                                                           

40.8.14-1 f. Measurement Uncertainty        20%             10%             
1         (flux)                                                            

40.8.14-1 g. Number of Platforms            (TBS)           (TBS)           
2                                                                           



40.8.15 Solar Extreme Ultraviolet Flux

Measurements of the full disk solar flux within several wavelength bands between 5 and 175 nm. Used as inputs to neutral atmospheric and ionospheric models.

Units:

Wavelength: nm

Flux: W/m2


Para.                              Thresholds         Objectives          
No.                                                                       

40.8.15- a. Measurement Range      5-130 nm in 4      1-175 nm in 10      
1                                  channels           channels            

40.8.15- b. Measurement            greater of 10-4    greater of 5x10-5   
2        Uncertainty               W/m2 or 20 %       W/m2 or 10 %        

40.8.15- c. Reporting Frequency    (5 hours)          (TBS)               
3                                                                         



40.8.16 Supra-Thermal through Auroral Particles

In-situ measurements of moderately energetic (< 30 keV) electrons and ions, primarily in the auroral regions. These measurements are input to space environment models and are used for low earth orbit anomaly assessments (surface charging). The mean energy and flux of the precipitating particles are particularly desired, although complete energy spectra are also needed. Measurements of particle energy spectra as a function of pitch angle are also desired. In particular, measurements inside and outside the loss cone angle are needed.

Units:

Energy: eV or keV

Flux: m-2sec-1ster-1keV-1


Para.                                      Thresholds      Objectives     
No.                                                                       

40.8.16-1 a. Horizontal Reporting          (TBS)           (TBS)          
          Interval                                                        

40.8.16-2 b. Horizontal Coverage           In-track        In-track       

          c. Measurement Range (electrons                                 
          and ions)                                                       

40.8.16-3  1. Energy                       30 eV - 30 keV  (TBS)          

40.8.16-4  2. Flux                         108-1015        (TBS)          

40.8.16-5 d. Pitch Angle Resolution        (TBS)           (TBS)          

          e. Measurement Precision                                        

40.8.16-6  1. Energy                       dE/E = 0.2      dE/E = 0.1     

40.8.16-7  2. Flux                         5%              1%             

40.8.16-8 f.  Measurement Accuracy         20 %            10 %           

40.8.16-9 g. Local Time Range              (TBS)           (TBS)          



40.8.17 Upper Atmospheric Airglow (TBR)

The Earth's upper atmosphere consists of neutral and ionized particles, most of which radiate at various wavelengths due to a variety of physical processes dependent on solar illumination (day/night), particle species, and atmospheric conditions. Measurements of this "airglow" can be used to infer information about the ionosphere (see EDR 40.8.5), neutral atmosphere (EDR 40.8.12), and the solar extreme ultraviolet flux (EDR 40.8.15). In addition, airglow imagery in the equatorial region and on the nightside after sunset can provide signatures of ionospheric disturbances associated with scintillation (EDR 40.8.11). Two types of airglow measurement geometry are possible: limb and disk. Disk measurements in the auroral zone are closely related to the Auroral Imagery requirement (EDR 40.8.3).

Units: rayleighs


Para. No.                                      Thresholds    Objectives   

           a.  Horizontal Cell Size                                       

40.8.17-1   1. Limb                            750 km        100 km       

40.8.17-2   2. Disk, 0 - 30 deg latitude       200 km        100 km       

40.8.17-3   3. Disk, 30 - 50 deg latitude      500 km        250 km       

40.8.17-4   4. Disk, 50 - 90 deg latitude      100  km       10 km        

           b.  Horizontal Reporting Interval                              

40.8.17-5   1. Limb                            750 km        100 km       

40.8.17-6   2. Disk                            100 km        10 km        

40.8.17-7  c.  Vertical Cell Size (Limb)       20 km         5 km         

40.8.17-8  d.  Vertical Reporting Interval     20 km         5 km         
           (Limb)                                                         

           e.  Horizontal Coverage                                        

40.8.17-9   1. Limb                            (TBS)         (TBS)        

40.8.17-10  2. Disk                            (TBS)         (TBS)        

40.8.17-11 f.  Vertical Coverage (Limb)        (TBS)         (TBS)        

           g.  Measurement Range                                          

40.8.17-12  1. Limb,  83.4 nm                  20 - 1000 R   10 - 1000 R  

40.8.17-13  2. Limb, 91.1 nm                   (TBS)          (TBS)       

40.8.17-14  3. Limb, 135.6 nm                  0.2 - 10 kR   0.1  - 10    
                                                             kR           

40.8.17-15  4. Limb, 140-180  nm               0.2 - 30 kR   0.1-30 kR    

40.8.17-16  5. Limb, 140-150 nm                (TBS)         (TBS)        

40.8.17-17  6. Limb, 165-180 nm                (TBS)         (TBS)        

40.8.17-18  7. Disk, 121.6 nm                  1 - 30 kR     0.5 - 30 kR  

40.8.17-19  8. Disk, 135.6 nm                  4 - 4000 kR   1 - 4000 R   

40.8.17-20  9. Disk, 140-180  nm               4 - 5000 kR   1 - 5000  R  

40.8.17-21  10. Disk, 140-150 nm               (TBS)         (TBS)        

40.8.17-22  11. Disk, 165-180 nm               (TBS)         (TBS)        

40.8.17-23  12. Disk, 630.0 nm                 (TBS)         (TBS)        

40.8.17-24 h.  Measurement Accuracy            10 % (TBR)    5 %          

40.8.17-25 i.  Measurement Precision           (TBS)         (TBS)        

40.8.17-26 j. Local Time Range (Limb)          (TBS)         (TBS)        

40.8.17-27 k:  Maximum Local Average Revisit   (TBS)         (TBS)        
           Time (Disk)                                                    



40.9 Notes on Space Enviromental EDRs

This section provides additional clarifaction of the nature of the Space Environment EDRs and the connections between them. Examples of techniques for making these measurements are given in order to illustrate and clarify the EDR requirements. These examples are not meant to indicate a program office preference for a particular method for meeting requirements. Alternate approaches which satisfy requirements will be considered equally.

40.9.1 Auroral Boundary

A measurement of the auroral boundary has typically been obtained in one of two ways. (1) In-situ energetic particle measurements (see EDR 40.8.16) can provide an indication of the boundary location in the satellite track. A statistical model of the auroral oval can then be used to extrapolate the location of the boundary to other local times. (2) An optical sensor (see EDR 40.8.3) which scans the Earth's disk can provide a two-dimensional image of the boundary. This can be done at various wavelengths, including the far ultraviolet and visible, but the latter is only useful at night, since auroral signals are overwhelmed during the day by scattered sunlight. A far-ultraviolet sensor can make auroral boundary measurements during both day and night.

40.9.2 Total Auroral Energy Deposition

Total Auroral Energy Deposition is calculated from measurements of the mean energy and flux of precipitating particles. These measurements may be made in one or both of two ways. (1) In-situ measurements of precipitating ion and electron fluxes (see EDR 40.8.16) may be combined with a statistical model of auroral activity to provide an estimate of the global average. (2) Far-ultraviolet images, or possibly a combination of far-ultraviolet and x-ray images (see EDR 40.8.3), can be used to derive mean precipitating particle energies and fluxes over a wide area, which can then be used to estimate the global average.

40.9.3 Auroral Imagery

Various products can be obtained from auroral imagery, depending on the wavelength(s) imaged. All wavelengths provide information on the location of the Auroral Boundary (EDR 40.8.1), and also allow identification of regions of enhanced auroral activity. (Such regions can impact communications and radar systems.) Infrared and visible wavelength imagery only provide this type of information at night, since auroral signals are overwhelmed during the day by scattered sunlight. Far ultraviolet images involving specific wavelength intervals, or a combination of far-ultraviolet and x-ray images, can also be used to determine maps of precipitating particle mean energy and flux (see EDR 40.8.16). Such maps could subsequently be used to determine the Total Auroral Energy Deposition (see EDR 40.8.2), as well as E-region electron densities in the auroral zone (see EDR 40.8.5). In combination with in-situ particle measurements (EDR 40.8.7), far-ultraviolet images can be used to calculate changes in upper atmospheric neutral densities due to auroral activity (see EDR 40.8.12).

40.9.4 Electric Fields

Electric fields may be inferred from measurements of ion drift velocities (see EDR 40.8.7).

40.9.5 Electron Density Profiles/Ionospheric Specification

A variety of techniques exist for making measurements of various portions of ionospheric electron density profiles. These include in-situ measurements of plasma parameters (EDRs 40.8.8 and 40.8.10), optical remote sensing techniques (EDRs 40.8.3 and 40.8.17), active and passive high frequency remote sensing, and total electron content measurements along lines-of-sight to GPS satellites. The following is a partial list of ionospheric parameters which may be useful to measure or infer as part of an effort to construct complete vertical profiles.

Parameter Definition

NmF2 Peak electron density in the F-region

HmF2 Altitude at which NmF2 occurs for a particular profile

NmE Peak electron density in the E-region

HmE Altitude at which NmE occurs for a particular profile

Htop Topside electron density scale height

Htrans Transition altitude between dominance of oxygen and lighter ions

NNPOESS In-situ electron density at NPOESS altitude

TECtopside Total Electron Content above NPOESS altitude

40.9.6 Geomagnetic Field

No comments.

40.9.7 In-situ Ion Drift Velocity

In-situ ion drift velocities can be used to determine electric fields (see EDR 40.8.4).

40.9.8 In-situ Plasma Density

No comments.

40.9.9 In-situ Plasma Fluctuations

No comments.

40.9.10 In-situ Plasma Temperatures

No comments.

40.9.11 Ionospheric Scintillation

In addition to direct measurements of amplitude and phase fluctuations, airglow imagery (EDRs 40.8.3 and 40.8.17) of ionospheric signatures in the far ultraviolet can also indicate the possible presence of scintillation for some geophysical regions.

40.9.12 Neutral Density Profiles/Neutral Atmospheric Specification

One technique for obtaining neutral densities involves measurement of airglow in the far ultraviolet (see EDR 40.8.17).

40.9.13 Radiation Belt/Low Energy Solar Particles

No comment.

40.9.14 Solar/Galactic Cosmic Rays

No comment.

40.9.15 Solar Extreme Ultraviolet Flux

A minimal estimate of the integrated solar EUV flux below 45 nm can be obtained from measurements of far ultraviolet airglow (see EDR 40.8.17). This measurement complements, but does not satisfy threshold requirements for this EDR.

40.9.16 Supra-Thermal through Auroral Particles.

These measurements have a variety of applications. These include calculation of in-track electron density profiles (see EDR 40.8.5) in the auroral zone E-region, calculation of total auroral energy deposition (EDR 40.8.2), and calculation of the auroral boundary location (EDR 40.8.1).

40.9.17 Upper Atmospheric Airglow (TBR)

Two types of airglow measurement geometry are possible: limb and disk. The limb-viewing geometry provides the best accuracy of the two for retrieval of ionospheric and neutral atmospheric parameters and comes the closest to retrieving complete vertical profiles. However, the long line-of-sight along the limb makes accurate measurements difficult in the auroral zone, with its high spatial variability. The disk-viewing geometry provides a more detailed information on horizontal structures in the ionosphere on the nightside, but requires additional assumptions to interpret the data, particularly on the dayside and in the auroral zone. Disk measurements in the auroral zone are closely related to the Auroral Imagery requirement (EDR 40.8.3).

The following emission features represent a subset of the possible emission features which could be measured to yield information on electron and neutral density profiles:

Wavelength Upper Atmospheric Source/EDR Product

83.4 nm O+ ion/Dayside electron densities (limb only)

91.1 nm O neutral/Nightside electron densities (limb or disk)

121.6 nm H neutral/Auroral zone proton fluxes (disk only)

135.6 nm O neutral/Night (limb & disk) and dayside (disk only) electron densities & dayside

neutral densities and solar EUV

140-150 nm N2 neutral/Dayside neutral densities (limb & disk) and auroral electron fluxes

(disk only)

165-180 nm N2 neutral/Dayside neutral (limb & disk) and electron (disk only) densities and solar

EUV & auroral electron fluxes (disk only)

630.0 nm O neutral/Nightside electron densities