VISIBLE/INFRARED IMAGER/RADIOMETER SUITE (VIIRS)
Sensor Requirements Document (SRD)
for
NATIONAL POLAR-ORBITING OPERATIONAL ENVIRONMENTAL SATELLITE SYSTEM (NPOESS) SPACECRAFT AND SENSORS
Prepared by
Associate Directorate for Acquisition
NPOESS Integrated Program Office
17 March 1997
Integrated Program Office
Silver Spring MD 20910
1. SCOPE 11.1 IDENTIFICATION 11.2 SENSOR SUITE OVERVIEW 11.3 DOCUMENT OVERVIEW 11.3.1 Conflicts 11.3.2 Requirement Weighting Factors 11.4 SYSTEM CLASSIFICATIONS N/A 22. APPLICABLE DOCUMENTS 32.1 GOVERNMENT DOCUMENTS 32.2 NONGOVERNMENT DOCUMENTS 42.3 REFERENCE DOCUMENTS 43. SENSOR REQUIREMENTS 73.1 DEFINITION 73.1.1 VIIRS Description 73.1.1.1 Specification Tree. 73.1.2 Top-Level VIIRS Functions 83.1.3 Sensor Modes 83.1.3.1 Common Sensor Modes 93.1.3.1.1 OFF Mode 93.1.3.1.2 OPERATIONAL Mode 93.1.3.1.3 DIAGNOSTIC Mode 93.1.3.1.4 SAFE HOLD Mode 93.1.3.2 VIIRS-Unique Mode and Submode Requirements 103.1.3.2.1 OFF Mode 103.1.3.2.2 OUTGASSING Mode 103.1.3.2.3 ACTIVATION Mode 103.1.3.2.4 EARLY ORBIT CHECKOUT Mode 103.1.3.2.5 OPERATIONAL Mode 103.1.3.2.6 CALIBRATION Mode(s) 113.1.3.2.7 SURVIVAL Mode 113.1.3.3 Mode Documentation 113.1.4 Operational Concept 123.1.4.1 Launch Operations Concept 123.1.4.1.1 Pre Launch 123.1.4.1.2 Launch and Injection 123.1.4.2 On-orbit Operational Concept 123.1.4.2.1 On-orbit Tests 123.1.4.2.2 On-orbit Operations 123.1.5 Missions. 133.2 SENSOR SUITE CHARACTERISTICS 133.2.1 Performance Characteristics 133.2.1.1 EDR Requirements 133.2.1.1.1 Primary EDRs 133.2.1.1.1.1 Imagery. 153.2.1.1.1.2 Sea Surface Temperature (SST). 193.2.1.1.1.2 Soil Moisture. 203.2.1.1.1.2 Aerosols. 213.2.1.1.1.3 Cloud Base Height. 233.2.1.1.1.4 Cloud Cover/Layers. 243.2.1.1.1.5 Cloud Effective Particle Size. 243.2.1.1.1.6 Cloud Optical Thickness (IORD Name: Cloud Optical Depth/Transmissivity) 253.2.1.1.1.7 Cloud Top Height. 253.2.1.1.1.8 Cloud Top Pressure 273.2.1.1.1.9 Cloud Top Temperature. 283.2.1.1.1.10 Albedo (Surface). 283.2.1.1.1.11 Land Surface Temperature. 293.2.1.1.1.12 Normalized Difference Vegetation Index (NDVI) (TBR). 293.2.1.1.1.13 Snow Cover/Depth. 293.2.1.1.1.14 Vegetation Index/Surface Type. 303.2.1.1.1.15 Currents 313.2.1.1.1.16 Fresh Water Ice. 323.2.1.1.1.17 Ice Surface Temperature. 333.2.1.1.1.18 Littoral Sediment Transport. 343.2.1.1.1.19 Net Heat Flux. 343.2.1.1.1.20 Ocean Color/Chlorophyll 343.2.1.1.1.21 Sea Ice Age and Sea Ice Edge Motion. 353.2.1.1.1.22 Mass Loading (TBR) (IORD Title - Turbidity). 363.2.1.1.2 Modifications and Clarifications of EDR Requirements 373.2.1.1.2.1 EDR Requirements Applying Under Clear Conditions Only 373.2.1.1.2.2 EDR Requirements Applying Under Daytime Conditions Only 373.2.1.2 Operational SDR Requirements [TBR] 383.2.1.2.1 Operational SDR Content [TBR] 383.2.1.2.2 Operational SDR Format 393.2.1.3 Operational RDR Requirements [TBR] 393.2.1.3.1 Operational RDR Content [TBR] 393.2.1.3.2 Operational RDR Format [TBR] 403.2.1.4 Earth Location Requirements 403.2.1.5 Algorithms [TBR] 403.2.1.5.1 Scope 403.2.1.5.2 Performance Requirements 413.2.1.5.3 Operational Algorithm Teams (OATs) 413.2.1.5.4 Convertibility to Operational Code 413.2.1.5.5 Multiple Sensor Requirements 413.2.1.6 Standard Earth Scenes 423.2.1.7 Real-time Data Downlink Data 423.2.1.8 Stored Data Downlink Data 433.2.1.9 Data Formatting and Compression (TBR) 433.2.1.10 Scan Requirements [TBD] 433.2.1.10.1 Type of Scan [TBD] 433.2.1.10.2 Swath Width [TBD] 433.2.1.10.3 Scan-to-scan Separation (overlap/underlap at nadir) [TBD] 443.2.1.10.4 Number and Types of Scan Modes (e.g., normal, calibration, autonomous, or commandable) [TBD] 443.2.1.10.5 Scan Rate [TBD] 443.2.1.11 Center frequency or wavelength [TBD] 443.2.1.12 Bandpass limits (N % response frequencies, where N = 50, 10, 1, etc.) [TBD] 443.2.1.13 Dynamic Range [TBD] 443.2.1.14 Linearity [TBD] 443.2.1.15 Quantization [TBD] 443.2.1.16 Sensitivity [TBD] 443.2.1.17 Absolute Radiometric Accuracy and Stability [TBD] 443.2.1.17.1 Absolute Accuracy [TBD] 443.2.1.17.2 Short-Term Stability [TBD] 443.2.1.17.3 Long-Term Stability [TBD] 443.2.1.17.4 Inter-band Accuracy [TBD] 443.2.1.18 Sensor Calibration [TBD] 443.2.1.18.1 Type of Calibration [TBD] 453.2.1.18.2 Frequency of Calibration [TBD] 453.2.1.18.3 Calibration Source Requirements (emissivities, temperatures, etc.) [TBD] 453.2.1.18.4 Calibration Source Monitoring Requirements [TBD] 453.2.1.18.5 Sensor Electronic Response Monitoring Requirements [TBD] 453.2.1.19 Spatial Resolution (bounds on MTF at specified spatial frequencies or bounding curves) [TBD] 453.2.1.20 Horizontal Sampling Interval [TBD] 453.2.1.21 Instantaneous Field of View (IFOV) [TBD] 453.2.1.21.1 IFOV Width at 50% Response Points [TBD] 453.2.1.21.2 IFOV Width Uniformity (detector to detector) [TBD] 453.2.1.21.3 Response Uniformity (intra-IFOV) [TBD] 453.2.1.21.4 Out-of-Field Response (bound on integrated response outside the IFOV) [TBD] 453.2.1.22 Optical Line-of-Sight (LOS) Alignment [TBD] 453.2.1.22.1 Maximum misalignment between sensor alignment reference and LOS axes [TBD] 453.2.1.22.2 LOS pointing knowledge [TBD] 453.2.1.22.3 Co-registration of spectral bands [TBD] 453.2.1.22.4 Maximum allowed alignment change (during ground test, launch, or on orbit) [TBD] 453.2.1.23 Optical Line-of-Sight (LOS) Jitter and Drift Requirements IRD/[TBD] 453.2.1.24 Polarization [TBD] (bound on sensitivity to polarization) 463.2.1.25 Crosstalk (bound on response in one channel due to signal in another channel) [TBD] 463.2.1.26 Out-of-band rejection (bound on response in a channel due to integrated out-of-band signal) [TBD] 463.2.1.27 Intra-band Response Uniformity [TBD] 463.2.1.27.1 Temporal [TBD] 463.2.1.27.2 Spatial [TBD] 463.2.1.28 Stray Light Rejection [TBD] 463.2.2 Sensor Capability Relationships 463.2.2.1 Reference Timelines [TBS] 463.2.2.2 Relationships between Sensors in Different Sensor Suites [TBR] 463.2.2.2.1 Relative Pointing Knowledge [TBR] 463.2.2.2.2 Relative Pointing Accuracy [TBR] 463.2.2.2.3 Co-Boresighting [TBR] 463.2.2.2.4 Synchronization [TBR] 463.2.2.3 Relationships between Sensors within a Suite [TBD] 463.2.3 Interface Requirements 463.2.4 Physical and Interface Characteristics 483.2.4.1 Mass Properties 49493.2.4.1.1 Sensor Mass Documentation 493.2.4.1.2 Sensor Mass Variability Documentation 493.2.4.1.3 Center of Mass 493.2.4.1.3.1 Center of Mass Allocation 493.2.4.1.3.2 Center of Mass Measurement and Documentation 493.2.4.1.4 Moments of Inertia 493.2.4.1.4.1 Moments of Inertia Measurement 493.2.4.1.4.2 Moments of Inertia Accuracy 503.2.4.1.4.3 Moments of Inertia Documentation 503.2.4.1.4.4 Moments of Inertia Variation Documentation 503.2.4.2 Dimensions 503.2.4.2.1 Physical Interface 503.2.4.2.1.1 Stowed and Critical Clearances 503.2.4.2.1.2 Mounting Provisions 513.2.4.2.1.3 Alignment 523.2.4.2.1.4 Structural Support 533.2.4.2.1.5 Sensor Structural Dynamics 533.2.4.3 Power 543.2.4.3.1 Sensor Internal Power 543.2.4.3.1.1 Peak Power TBD 543.2.4.3.1.2 Power Cycle TBD 543.2.4.3.1.3 On-orbit Power TBD 543.2.4.3.1.4 Launch Power TBD 543.2.4.3.1.5 End-of-life Power TBD 543.2.4.3.2 Sensor External Power 543.2.4.3.3 Electrical Power Interface Requirements 543.2.4.3.3.1 Electrical Interfaces 543.2.4.3.3.2 Electrical Current 563.2.4.3.3.3 Grounds, Returns, and References 563.2.4.3.3.4 Power Harnesses 573.2.4.3.3.5 Signal Cabling 573.2.4.4 Survivability 583.2.4.5 Endurance (TBR) 583.2.4.6 Protective Coatings and Finishes 583.2.4.7 Thermal 593.2.4.7.1 General 593.2.4.7.2 Thermal Isolation to Spacecraft 593.2.4.7.3 Heat Transfer 593.2.4.7.3.1 Heat Transfer 593.2.4.7.3.2 Radiation 593.2.4.7.4 Temperature Ranges 603.2.4.7.4.1 Spacecraft Temperature Range 603.2.4.7.4.2 Thermal Uncertainty Margins 603.2.4.7.4.3 Sensor Temperature Range 603.2.4.7.5 Temperature Monitoring 603.2.4.7.5.1 Mechanical Mounting Interface Temperature Monitoring 603.2.4.7.5.2 Sensor Temperature Monitoring 603.2.4.7.5.3 Temperature Sensor Locations 613.2.4.7.6 Thermal Control Design 613.2.4.7.6.1 Thermal Control Hardware 613.2.4.7.6.2 Survival Heater Design 613.2.4.7.6.3 Multilayer Insulation 623.2.4.7.6.4 Other Considerations 623.2.4.8 Data and Command Interface 623.2.4.8.1 General Command Electrical 623.2.4.8.1.1 Interface Conductors 623.2.4.8.1.2 Interface Circuitry Isolation 623.2.4.8.1.3 Interface Fault Tolerance 623.2.4.8.1.4 Power Bus 623.2.4.8.2 Command and Telemetry Data Bus Requirements 633.2.4.8.2.1 Bus Functions 633.2.4.8.2.2 Bus Type 633.2.4.8.2.3 Bus Configuration 643.2.4.8.3 General Bus Requirements 643.2.4.8.3.1 Electrical Interface 643.2.4.8.3.2 Data Bus Monitoring 653.2.4.8.4 Sensor Commands and Memory Load 653.2.4.8.4.1 Command Types 653.2.4.8.4.2 Packetization for Commands and Memory Loads 653.2.4.8.4.3 Documentation 653.2.4.8.4.4 Critical Commands 663.2.4.8.4.5 Frame Sync and Time Code Data 663.2.4.8.5 Health and Status Telemetry Data 663.2.4.8.5.1 Telemetry Diagnostic Data 663.2.4.8.6 Low Rate Science Data 663.2.4.8.6.1 Telemetry and Low Rate Data Packetization 663.2.4.8.7 Data Bus Sampling Rate 663.2.4.9 High Rate Bus 673.2.4.9.1 Bus Functions 673.2.4.9.2 High Rate Data Bus Transmission Rate 673.2.4.9.3 Bus Type 673.2.4.9.4 High Rate Data Packetization 673.2.5 Sensor Quality Factors 673.2.5.1 Reliability 673.2.5.1.1 Operational Service Life 673.2.5.1.2 Maintainability 673.2.6 Environmental Conditions 683.2.6.1 Natural Environment Characteristics 683.2.6.1.1 Total Ionizing Dose Environment 683.2.6.1.2 Cosmic Ray and High Energy Proton Environment 693.2.6.1.2.1 Single Events Radiation Environment 693.2.6.1.2.2 Displacement Damage 703.2.6.2 Launch Environment 703.2.6.2.1 Thermal (TBS) 703.2.6.2.1.1 Temperatures 703.2.6.2.1.2 Heat Flux (TBS) 713.2.6.2.1.3 Free Molecular Heating 713.2.6.2.2 Shock (TBS) 723.2.6.2.3 Acceleration Load Factors 723.2.6.2.4 Vibration 723.2.6.2.5 Acoustics 723.2.7 Transportability 743.2.8 Flexibility and Expansion 753.2.8.1 Operational Computer Resource Reserves 753.2.8.1.1 Computer Resource Reserves for Operational Space Elements 753.2.8.1.1.1 Data Processing Processor Reserves 753.2.8.1.1.2 Data Processing Primary Memory Reserves 753.2.8.1.1.3 Data Processing Peripheral Data Storage (Secondary Memory) Reserves 753.2.8.1.1.4 Data Processing Data Transmission Media 763.2.8.1.1.5 Data Processing Software/Firmware 763.3 DESIGN AND CONSTRUCTION 763.3.1 Materials 763.3.1.1 Toxic Products and Formulations 763.3.1.2 Parts Selection 763.3.1.3 Material Selection 773.3.2 Electromagnetic Radiation 773.3.2.1 Electromagnetic Interference (EMI) Filtering of Spacecraft Power 773.3.2.2 Electromagnetic Compatibility 773.3.2.2.1 General 773.3.2.2.2 Baseline Requirements 783.3.2.2.2.1 Sensor Electromagnetic Compatibility 783.3.2.2.2.2 Interface Margins 783.3.2.2.3 External Environment 783.3.2.2.2.3 Spacecraft Charging from All Sources 793.3.2.3.3 Wiring 793.3.2.3.4 Conducted and Radiated Interface Requirements 793.3.2.3.4.1 Radiated Emission RE101 793.3.2.3.4.2 Radiated Emissions RE102 793.3.2.3.4.3 Radiated Susceptibility RS101 793.3.2.3.4.4 Radiated Susceptibility RS103 793.3.3 Nameplates and Product Marking (See 5.2) 803.3.4 Workmanship 803.3.5 Interchangeability 803.3.6 Safety Requirements 803.3.6.1 Design Safety Criteria 803.3.7 Human Engineering 813.3.8 Nuclear Control 813.3.9 Security 813.3.9.1 Communications Security (COMSEC) 813.3.9.2 Computer Security (COMPUSEC) 823.3.10 Government Furnished Property Usage 823.3.11 Computer Resources 823.3.11.1 Operational Computer Resources 823.3.11.1.1 Operational Computational Equipment 823.3.11.1.2 Operational Application Software (TBD) 823.3.11.1.3 Operating Systems Used in Operational Computers 823.3.11.1.3.1 Sensors Flight Software Requirements 823.3.11.1.3.2 Programming Language 823.3.11.1.4 Software Coding Conventions 833.3.11.1.5 Year 2000 Software Requirements 833.3.12 Sensor Design Requirements 833.3.12.1 General Structural Design 833.3.12.2 Strength Requirements 833.3.12.2.1 Yield Load 833.3.12.2.2 Ultimate Load 833.3.12.3 Stiffness Requirements 843.3.12.3.1 Dynamic Properties 843.3.12.3.2 Structural Stiffness 843.3.12.3.3 Component Stiffness 843.3.12.4 Structural Factors of Safety 843.3.12.4.1 Flight Limit Loads 843.3.12.4.2 Pressure Loads (TBR) 853.3.12.5 Design Load Conditions 863.3.12.6 Sensor Fluid Subsystems 863.3.12.6.1 Tubing 863.3.12.6.2 Separable Fittings 863.3.12.7 Moving Mechanical Assemblies 873.3.12.7.1 Actuating Devices (See 3.3.6.1) 873.3.12.7.2 Sensor Disturbance Allocation 873.3.12.7.3 Sensor Mechanisms 873.3.12.7.4 Uncompensated Momentum 873.3.12.7.5 Sensor Disturbance Allocations 873.3.12.7.5.1 Constant and Periodic Disturbance Torque Limits 873.3.12.7.5.2 Torque Profile Documentation 883.3.12.7.5.3 Thrust Direction Definition 883.3.12.8 Magnetics 883.3.12.9 Access 893.3.12.9.1 Access Identification 893.3.12.9.2 General Access 893.3.12.10 Mounting/Handling 893.3.12.10.1 Handling Fixtures 893.3.12.10.2 Mounting Orientation 893.3.12.10.3 Sensor to Spacecraft Integration and Test Mounting 893.3.12.10.4 Non-Flight Equipment 893.3.12.11 Venting 903.3.13 Operational Ground Equipment: General Design Requirements (TBD) 903.3.14 Non-operational Ground Equipment: (TBD) 903.3.15 General Construction Requirements 903.3.15.1 Processes and Controls for Space Equipment 903.3.15.1.1 Assembly Lots 913.3.15.1.2 Contamination (TBR) 913.3.15.1.2.1 Contamination Control Requirements 913.3.15.1.2.2 Facility Environmental Requirements 923.3.15.1.2.3 Sensor Inspection and Cleaning During I&T 923.3.15.1.2.4 Sensor Purge Requirements 923.3.15.1.2.5 Fabrication and Handling 923.3.15.1.2.6 Device Cleanliness 933.3.15.1.2.7 Outgassing Sensor Sources of Contamination 933.3.15.1.2.8 Atomic Oxygen Contamination 933.3.15.1.3 Electrostatic Discharge 943.4 DOCUMENTATION 943.4.1 Specifications 943.4.2 Interface Control Documents 943.4.3 Drawings and Associated List 943.4.4 Software (Including Databases). 943.4.5 Technical Manuals 943.5 LOGISTICS (TBD) 943.5.1 Maintenance Planning (TBD) 943.5.1.1 Sensor Maintenance Concepts (TBD) 953.5.2 Support Equipment (TBD) 953.5.3 Packaging, Handling, Storage, and Transportation (PHS&T) (TBD) 953.5.4 Facilities (TBR) 953.6 PERSONNEL AND TRAINING (TBD) 953.7 SENSOR SUITE COMPONENT CHARACTERISTICS (if required) (TBD) 954. QUALITY ASSURANCE AND TESTING PROVISIONS 964.1 Quality Assurance 964.1.1 SPECIAL TESTS AND EXAMINATIONS 964.1.1.1 Inspections and Tests of the Sensor 964.1.1.1.1 Sensor Parts, Materials, and Process Controls. 964.1.1.1.2 Sensor Records. 964.1.1.1.3 Sensor Manufacturing Screens 974.1.1.1.4 Non-conforming Material 974.1.1.1.5 Sensor Design Verification Tests 974.2 TESTING 974.2.1 Philosophy of Testing 974.2.2 Location of Testing 974.2.3 Physical Models 974.2.3.1 Engineering Development Unit (EDU) 974.2.3.2 Mass Model 984.2.3.3 Spacecraft/Sensor Mechanical Interface Simulator (TBS) 984.2.3.4 Spacecraft/Sensor Electrical Interface Simulator (TBS) 984.2.4 Math Model Requirements 984.2.4.1 Finite Element Model 984.2.4.2 Thermal Math Model 984.2.5 Structural Analyses 994.2.6 Developmental Testing 994.2.7 Acceptance and Protoqualification Testing 994.2.7.1 Random Vibration Testing 1004.2.7.1.1 Acceptance Level Random Vibration Testing 1004.2.7.1.2 Protoqualification Level Random Vibration Testing 1014.2.7.2 Sine Vibration Testing 1024.2.7.2.1 Acceptance Level Sine Vibration Testing 1034.2.7.2.2 Protoqualification Level Sine Vibration Testing 1034.2.7.2.3 Design Strength 1034.2.7.3 Acceleration Testing 1034.2.7.4 Shock Testing 1044.2.7.4.2 Protoqualification Level Sensor Shock Testing 1044.2.7.5 Acoustic Testing 1054.2.7.5.1 Acceptance Level Acoustic Testing 1054.2.7.5.2 Protoqualification Level Acoustic Testing 1064.2.7.6 Thermal Testing 1064.2.8 EMC/EMI Testing 1064.2.9 Current Margin Testing 1074.2.10 Deployment Testing 1074.2.11 Outgassing 1074.2.12 Requalification of Existing Designs. 1074.2.13 Lifetime Testing 1074.2.14 Pre-launch Validation Tests. 1074.2.14.1 Sensor Pre-launch Validation Tests. 1084.3 VERIFICATION 1084.3.1 Standard Scenes 1084.3.2 Verification Methods 1084.3.3 Requirements Validation 1094.3.4 Data Bases 1094.3.5 External/Built-in Testing 1104.3.6 Burn-in 1105. PREPARATION FOR DELIVERY 1105.1 PRESERVATION AND PACKAGING 1105.2 MARKINGS 110
LIST OF FIGURES
Figure 3.1.1.1 SPECIFICATION TREE 8Figure 3.2.3 Partial System Internal Interfaces 47Figure 3.2.4.3.3.1. Spacecraft-Sensor Electrical Interfaces 55Figure 3.2.4.8.2. Data Transfer Interface 63Figure 3.2.4.8.2.3. Command and Data Handling Interface Topology 64Figure 3.2.6.2.1.1 Maximum PLF Inner Temperatures 71Figure 3.2.6.2.3 MLV Quasi-Static Load Factors 72Figure 3.2.6.2.5 MLV Acoustic Levels 73Figure 3.3.12.7.5.1 Allowable Transmitted Torque 88Figure 4.2.7.1.1 Random Vibration - Acceptance Levels 101Figure 4.2.7.1.2 Random Vibration - Protoqualification Levels 102Figure 4.2.7.2.2 Sinusoidal Protoqualification Test Levels 103Figure 4.2.7.4 Shock Spectrum (Q=10) 104
LIST OF TABLES
Table 3.2.4.7.3.2 Worse-Case Hot and Cold Environments 60Table 3.2.4.7.6.1. Thermal Control Hardware Responsibility 61Table 3.2.6.1.1 Total Ionizing Dose Environment 68Table 3.2.6.2.5 Maximum Acoustic Levels 74Table 3.3.12.4.1 Structural Design Factors of Safety 84Table 3.3.12.4.2 Factors of Safety for Pressurized Components 85Table 4.2.7.1.1 Random Vibration - Acceptance Test Levels 100Table 4.2.7.1.2 Random Vibration - Protoqualification Levels 102Table 4.2.7.2.2 Sinusoidal Test Levels 103Table 4.2.7.5.1 Acceptance Acoustics Levels 105
This Sensor Requirements Document (SRD) sets forth the requirements for the Visible/Infrared Imager/Radiometer Suite of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) and is hereinafter referred to as the VIIRS.
The purpose of the VIIRS is to collect visible and infrared radiometric data. These data are processed and delivered to the users in the form of Raw Data Records (RDRs), Sensor Data Records (SDRs), and Environmental Data Records (EDRs).
This document contains all performance requirements for sensor suite. This document also defines all sensor-spacecraft interfaces for the sensor suite. The contractor should use the document as the basis of a proposed sensor suite specification. The documentation listed in section 2.0 follows an approach of minimum specs and standards. The contractor may add to or revise the documents listed in section 2.0 in coordination with the government. The term "[TBD]" applied to a missing requirement means that the contractor should determine the missing requirement in coordination with the government. The term "[TBS]" means that the government will supply the missing information in the course of the contract. The term "[TBR]" means that the requirement is subject to review for appropriateness by the contractor or the government. The government may change "[TBR]" requirements in the course of the contract.
Appendix A contains a definition of the terms used throughout the document. Appendix B, NPOESS survivability requirements, is classified and will be made available after contract award. Appendix C is a Sensor Data Record Characteristics section presently TBR. Appendix D contains the NPOESS EDR requirements. Appendix E contains the RDRs and EDRs required for each Central and Field Terminal (TBR). Appendix F defines the acronyms and abbreviations used throughout the document. Appendix G describes Potential Pre-Planned Product Improvements. Appendix H is the Verification Cross Reference Matrix (TBD).
SRDX1.3.1-1
In the event of conflict between the referenced documents and the contents of this specification, the contents of this specification shall be the superseding requirements.
SRDX1.3.1-2
In the event of a conflict involving the external interface requirements, or in the event of any other unresolved conflict, the contracting officer shall determine the order of precedence.
The requirements stated in this specification are not of equal importance or weight. The following three paragraphs define the weighting factors incorporated in this specification.
a. Shall designates the most important weighting level; that is, mandatory. Any deviations from these contractually imposed mandatory requirements require the approval of the contracting officer.
b. Should designates requirements requested by the government and are not mandatory. Unless required by other contract provisions, noncompliance with the should requirements does not require approval of the contracting officer.
d. Will designates the lowest weighting level. These will requirements designate the intent of the government and are often stated as examples of acceptable designs, items and practices. Unless required by other contract provisions, noncompliance with the will requirements does not require approval of the contracting officer and does not require documented technical substantiation.
The following documents of the exact issue shown form a part of this SRD to the extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, see Section 1.3.1. Tailoring of documents in this section is (TBR).
SPECIFICATIONS:
Military
DOD-E-83578A General Specification for Explosive Ordnance
May 96 for Space Vehicles,
Mil-A-83577B Moving Mechanical Assemblies for Space Launch
Feb 88 Vehicles
STANDARDS:
Federal
FED-STD-209E Airborne Particulate Cleanliness Classes in Sep 92 Cleanrooms and Clean Zones
Military
MIL-STD-461D Electromagnetic Emission and Susceptibility
Jan 93 Requirements for the Control of Electromagnetic
Interference
MIL-STD-462D Measurement of Electromagnetic Interference
Jan 93 Characteristics
MIL-STD-1540C Test Requirements for Launch, Upper Stage, and
Sep 94 Space Vehicles
MIL-STD-1541A Electromagnetic Compatibility Requirements for
Dec 87 Space Systems
MIL-STD-1553B Digital Time Division Command/Response
Jan 96 Multiplex Data Bus
MIL-STD-1773B Fiber Optics Mechanization of an Aircraft
May 88 Internal Time Division Command/Response
Multiplex Data Bus
Department of Commerce/NOAA: None (TBR)
OTHER PUBLICATIONS:
Regulations
AFM 91-201 Explosive Safety Standards
7 Oct 94
EWR 127-1 Eastern and Western Range Safety Requirements
31 Mar 95
Handbooks: None (TBR)
Bulletins: None (TBR)
Other
GPS ICD 200 REV "NAVSTAR GPS Space Segment/Navigation User
C, 19 January Interface"(U)
1995
GPS ICD 203, REV "NAVSTAR GPS SA/AS Requirements (S)
B 22 Dec 1993
(Contractors requiring copies of specifications, standards, handbooks, drawings, and publications in connection with specified acquisition functions should obtain them from the contracting activity or as directed by the contracting officer.)
The following documents of the exact issue shown form a part of this SRD to the Extent specified herein. In the event of conflict between the documents referenced herein and the contents of this specification, see Section 1.3.1.
SPECIFICATIONS: None (TBR)
STANDARDS:
CCSDS 203.0-B-1 CCSDS Recommendations for Space Data System
Jan 87 Standards. Telecommand, Part 3: Data
Management Service, Architectural Definition,
Issue 1
CCSDS 701.0-B-2 CCSDS Recommendations for Advanced Orbiting
Dec 87 Systems, Networks and Data Links, Architectural
Specification
National Hazardous Materials Management Program
Aerospace
Standard (NAS)
411
Rev 2, 29 Apr 94
DRAWINGS: None (TBR)
OTHER PUBLICATIONS: None (TBR)
The following documents are for reference only and do not form a part of this specification. They are listed here because various parts of the SRD refer to them.
SPECIFICATIONS:
Military: None (TBR)
STANDARDS:
DOD 5200.28-STD Department of Defense Trusted Computer System
Mar 88 Evaluation Criteria
MIL-STD-129M Marking for Shipment and Storage Notice 1, 15
1 Jun 93 Sep 89
MIL-STD 961D DoD Standard Practice for Defense
Aug 95 Specifications, w/ Notice 1
MIL-STD-498 Software Development and Documentation
5 Dec 94
MIL-STD-882c System Safety Program Requirements
Jan 93
MIL-STD-1246C Military Standard Product Cleanliness Levels
Apr 94 and Contamination Control Program
MIL-STD-1522A Standard General requirements for Safe Design
May 84 and Operation of Pressurized Missile and Space
Systems
MIL-STD-1542B Electromagnetic Compatibility (EMC) and
Nov 91 Grounding Requirements for Space Systems
Facilities
MIL-STD-1543B Reliability Program Requirements for Space and
Oct 88 Launch Vehicles
MIL-STD-1547A Parts and Materials Program for Space and
Dec 92 Launch Vehicles
MIL-STD-1809 (USAF) Space Environments for USAF Space
Feb 91 Vehicles
TM-86-01 Technical Manual Contract Requirements
Department of Commerce
DOC Sep 95 National Telecommunications and Information Edition Administration, Manual of Regulations for Sep 95 Federal Radio Frequency Management
NOAA
S24.801 Preparation of Operations and Maintenance
2 Dec 88 Manuals
S24.806 Software Development, Maintenance, and User
30 Apr 87 Documentation
S24.809 Grounding Standards
Dec 89
NASA
PPL-21 Preferred Parts List, Goddard Space Flight
March 1995 Center (Updated May 1996)
SP-R-0 022A General Specification, Vacuum Stability
(JSC) Requirements of Polymeric Material for
9 Sep 74 Spacecraft Application
NASA Tech Memo Orbital Debris Environments for Spacecraft
100471 Designed to Operate in Low Earth Orbit
SP 8031 NASA Space Vehicle Design Criteria/Structures
1969
OTHER PUBLICATIONS:
Regulations: None (TBR)
Handbooks
DOD-HDBK-263B Electrostatic Discharge Control Handbook for
(date) Protection of Electrical and Electronic Parts,
Assemblies, Equipment
MIL-HDBK-340 Application Guidelines for MIL-STD-1540B
1 Jul 85
DOD-W-83575 Gen Spec for Wiring Harness, Space Vehicle,
Jun 96 Design and Testing
MIL-I-46058 Insulating Compound. Electrical (for Coating
Printed Circuit Assemblies)
1985 Handbook of Geophysics and Space Environments
AFM 15-111 Surface Weather Observations
1 Sep 96
Bulletins
Other
TRD for NPOESS Technical Requirements Document (TRD) for
(current National Polar- Orbiting Operational
version) Environmental Satellite System (NPOESS)
Spacecraft Payloads
IRD for NPOESS Interface Requirements Document (IRD) for
(current National Polar-Orbiting Operational
version) Environmental Satellite System (NPOESS)
Spacecraft
IORD for NPOESS Integrated Operational Requirements Document
28 Mar 96 (IORD) for National Polar Orbiting Operational
Environmental Satellite System (NPOESS)
Spacecraft Payloads
ASTME-595-93 Standard Test method for Total Mass Loss and
(current Collected Volatile Condensable Materials for
version) Outgassing in a Vacuum Environment
Attachment C AMSU-A Instrument Performance and Operation
S-480-80 Specification (for the EOS/METSAT Integrated
Revised Programs); NASA GSFC
December 1994
SYS/AMS/J0105/BA AMSU-B Instrument System Specification (British
E Aerospace)
03 Feb 1993
(Technical society and technical association specifications and standards are generally available from reference libraries. They are also available in technical groups and using federal agencies. Contact the contracting officer regarding any referenced document not readily available from other sources.)
SRDV3.1.1-1
The VIIRS shall consist of one or more instruments designed to measure scene radiance in spectral bands within the visible to thermal infrared range (from 0.3 to 14 microns, approximately).
SRDV3.1.1-2
The contractor shall determine the sensor architecture, that is, the number of instruments and discrete modules comprising the sensor suite.
The contractor is responsible for determining the sensor characteristics and performance requirements needed to satisfy a specified subset of the Environmental Data Record (EDR) requirements. (See Sec. 3.2.1)
The possibility that the government may choose to fly a VIIRS instrument on a "mission of opportunity" satellite to provide early NPOESS data to users should not be construed to imply any additional or more stringent constraints on the VIIRS design.
Figure 3.1.1.1 shows a partial specification tree for the NPOESS System.
Figure 3.1.1.1 SPECIFICATION TREE
SRDV3.1.2-1
Each VIIRS instrument shall perform the following functions throughout its operational lifetime:
Each VIIRS instrument should perform the following functions, if needed to meet requirements, based on the contractor's design:
SRDV3.1.3-1
The VIIRS shall implement the following operational modes as a minimum:
In addition, the VIIRS will implement one or more CALIBRATION Modes, if needed.
SRDV3.1.3-2
Each VIIRS instrument shall be separately commandable into any of the above modes, regardless of the operational mode of any other instrument in the suite or on the spacecraft. The contractor may recommend additional modes or submodes, as appropriate to his specific design and operational concept.
The OFF, OPERATIONAL, DIAGNOSTIC, and SAFE HOLD modes are common to all NPOESS mission critical sensors.
SRDV3.1.3.1.1-1
In the sensor OFF mode, no power shall be supplied to the sensor, with the possible exception of power to survival heaters and critical health and safety monitoring components.
SRDV3.1.3.1.2-1
In the OPERATIONAL mode the VIIRS shall be in its full functional configuration.
SRDV3.1.3.1.2-2
In this mode earth scene radiance, calibration, and housekeeping data shall be acquired.
SRDV3.1.3.1.3-1
The sensor DIAGNOSTIC mode shall support housekeeping and software updates.
SRDV3.1.3.1.3-2
The DIAGNOSTIC mode shall support trouble shooting.
In the SAFE HOLD mode, health and status data are collected and transmitted. Mission and calibration data are not collected.
SRDV3.1.3.1.4-1
The SAFE HOLD mode is a power conservation mode. The sensor shall accept a command in the event the spacecraft enters an anomalous configuration or orientation as determined by the spacecraft computer. A power subsystem anomaly is such an event.
SRDV3.1.3.1.4-2
The spacecraft C&DH will issue power conservation re-configuration commands to the sensors via the data bus that will place the sensor in a safe configuration. The return to the OPERATIONAL mode shall require ground intervention.
SRDV3.1.3.1.4-3
In this mode most components shall be turned off, with survival heaters activated (See 3.1.4.2.7).
The VIIRS will be in the OFF mode during launch phase and orbit acquisition.
To the maximum extent feasible, the VIIRS should be designed to allow the spacecraft to monitor its health and safety while in the OFF mode. For example, critical instrument temperatures may be monitored by the spacecraft.
SRDV3.1.3.2.1-1
Thermostatically controlled survival heaters connected to a separate power bus shall be provided, as necessary, to protect the instrument in this mode.
SRDV3.1.3.2.2-1
The VIIRS will be in the OUTGASSING mode during the early days of the mission during which time the instruments shall be non-operating or in partial operation. This mode may also be exercised at any time during the mission when decontamination is required. Instrument subassemblies or components are powered on in this mode only as necessary to facilitate outgassing, not to provide valid earth scene or calibration data.
SRDV3.1.3.2.2-2
In this mode the optics, cooler, and other critical components shall be protected from contamination.
SRDV3.1.3.2.2-3
This mode shall also include the capability to warm up any cold critical elements to allow any contamination build-up to outgass.
In the ACTIVATION mode the VIIRS turns on and instrument components are warming up, or cooling down, to their operating temperatures. This mode terminates when all instrument temperatures, biases, and currents have stabilized within specified operational limits.
This mode also includes any deployments and opening of covers or shutters.
The EARLY ORBIT CHECKOUT mode is a test mode in which the VIIRS collects data to verify that performance complies with design and meets requirements. This mode may be regarded as a submode of the common sensor DIAGNOSTIC Mode.
SRDV3.1.3.2.4-1
To support this mode and for anomaly resolution the contractor shall provide the capability to selectively disable any on-orbit processing operation that combines or compresses raw data in any manner. Examples of such processing operations are: spatial aggregation of pixel samples; temporal aggregation of pixel samples; averaging of pixel data acquired while viewing calibration sources; averaging of calibration instrumentation data such as source temperature measurements; and data compression.
SRDV3.1.3.2.5-1
The OPERATIONAL mode shall have the following two submodes, at a minimum:
DAYTIME Mode: Normal daytime operating mode, observing in all bands except the low-light visible band.
NIGHTTIME Mode: Normal nighttime operating mode, observing in the low-light visible band and in the emission-dominated infrared bands. In this mode the reflection-dominated bands, such as the ocean color bands, could be turned off.
In addition, the OPERATIONAL mode should have the following submode:
TERMINATOR Mode: A combined operating mode where the scene contains both day and night information.
SRDV3.1.3.2.5-2
In the OPERATIONAL mode the VIIRS shall generate the following four data streams (TBR):
(1) Regional (high resolution) stored data
Regional imagery (Sec. 3.2.1.1.1.13.2.1.1.1.1) is incorporated into the regional real-time and stored data streams.
Global imagery (Sec. 3.2.1.1.1.13.2.1.1.1.1) is incorporated into the global real-time and stored data streams.
The allocation of other data generated by the VIIRS into these data streams is TBD.
In the CALIBRATION mode(s) the VIIRS views a calibration source and acquires calibration data only. Collection of earth scene radiance data is suspended in this mode. In this mode the functional configuration and/or operation of a VIIRS instrument is modified relative to the OPERATIONAL mode configuration and/or operation. For example, the scan may be modified so that a VIIRS instrument views an external calibration source such as the sun or moon.
The SURVIVAL mode is an emergency off mode. The VIIRS will be commanded into this mode in the event of a spacecraft emergency. The intent is that all instruments on the spacecraft will be reactivated upon spacecraft recovery. Reactivation requires ground intervention.
SRDV3.1.3.2.7-1
Initiation of this mode shall require a minimum of commands. Ideally no instrument reconfiguration is necessary before operating power cut off.
SRDV3.1.3.2.7-2
Thermostatically controlled survival heaters connected to a separate power bus shall be provided, as necessary, to protect the instrument in this mode.
SRDV3.1.3.3-1
The complete set of VIIRS modes deemed necessary by the contractor shall be defined in the VIIRS A-specification and in the VIIRS ICD.
SRDV3.1.3.3-2
All commands relating to mode configuration and re-configuration shall be defined in the VIIRS A-specification and in the VIIRS ICD.
The satellite will be transported directly to the launch base where final vehicle preparations and checkout will be accomplished. Final inter-segment and launch system verification tests will be accomplished prior to launch.
During launch and injection to the operational orbit, the various spacecraft subsystems may be powered on or turned off in order to provide protection from the launch and injection environments or to comply with other specified requirements. Spacecraft telemetry to monitor vehicle status will be provided during launch and injection. Transmission of launch vehicle telemetry may satisfy this requirement during the launch phase. Spacecraft telemetry transmission to ground monitoring stations would be used to the extent practicable during the injection phase. After insertion into its operational orbit and separation from the launch vehicle, appropriate deployments would be initiated by memory command. Early orbit check-out will be conducted at the NPOESS primary SOC in Suitland, MD.
The NPOESS satellite will operate in a near circular, sun-synchronous orbit. The nominal orbit for the spacecraft is 833 km altitude, 98.7 (TBR) degrees inclination. The orbit will be a "precise" orbit (i.e., altitude maintained to TBD km, nodal crossing times maintained to 10 minutes throughout the mission lifetime ) to minimize orbital drift (precession). NPOESS must be capable of flying at any equatorial node crossing time. However, the nominal configuration is with the satellite orbits equally spaced, with 0530 and 1330 nodal crossing times for the U.S. Government spacecrafts and 2130 for the METOP spacecraft.
The sun Beta angle, , is the angle between the solar vector (i.e. the spacecraft-sun line) and the orbit plane. For instrument thermal design purposes, the range of for the NPOESS missions is ± 90 degrees. The satellite will maintain the sun on the appropriate side of the spacecraft to meet the ‘all beta’ requirement.
SRDV3.1.4.3-1
Sensor suite design shall allow for approximately a 5 degree infringement of sun on the cold space side of the spacecraft in the case of a noon or midnight orbit.
The initial on-orbit period is devoted to a complete spacecraft checkout and the calibration and performance verifications of the payload(s). The spacecraft and payload performance verification tests may be repeated at appropriate times during the operational phase of the mission.
SRDV3.1.4.2.2-1
When the VIIRS is in the OPERATIONAL mode and when the satellite is in the AUTONOMOUS mode (See IRD, Sec. 3.4.2.), the VIIRS shall automatically switch between daytime, nighttime, terminator (if implemented), and routine CALIBRATION modes (if implemented).
.
SRDV3.1.4.2.2-3
The VIIRS shall be commandable into any operational mode at any time, overriding any pre-programmed modes or earlier commands to switch modes.
SRDV3.1.4.2.2-4
The VIIRS shall be capable of operating for up to 21 days, with a goal of up to 60 days, without commands when the satellite is in the AUTONOMOUS mode.
When the satellite is in the AUTONOMOUS mode, the VIIRS should be capable of performing housekeeping tasks without ground contact.
When the satellite is in the AUTONOMOUS mode sensor anomaly resolution should be provided to the extent possible based on available resources.
The mission of the VIIRS is to provide high quality imagery and radiometric data within the visible and infrared spectral regions to support worldwide DoD and civilian operations and high-priority programs.
The data product level requirements of the EDRs supported by the VIIRS drive the performance characteristics of the VIIRS.
SRDV3.2.1-1
Instrument level requirements shall be derived by the contractor based on a flowdown of EDR requirements to instrument performance requirements using the contractor's EDR algorithms.
Performance requirements in the OPERATIONAL mode are provided below.
SRDV3.2.1-2
Performance requirements in other modes shall be recommended by the contractor. Requirements for other modes must be consistent with the functions and purposes of the mode as described above in Section 3.1.33.1.3.
SRDV3.2.1.1-1
The VIIRS design and algorithms shall be adequate to allow the environmental data records listed in Section 3.2.1.1.1 to be met.
SRDV3.2.1.1-2
At a minimum, the VIIRS design and algorithms shall allow the EDR requirements to be satisfied at the threshold level. The generation and delivery of operational EDRs will be the responsibility of the IDPS (TSPR) contractor, not the VIIRS contractor.
SRDV3.2.1.1.1-1
Requirements for the following "primary" EDRs shall be satisfied using sensing data acquired by the VIIRS, supplemented in some cases by data derived from other (non-VIIRS) sensors, data bases, and ancillary sources:
SRDV3.2.1.1.1-2
If data from another non-VIIRS sensor are required to meet a threshold for any of these EDRs, the VIIRS contractor shall identify the data content, quality, and timeliness required from the other sensor. The government may impose modified requirements on the VIIRS if:
Any requirement modifications will be at the government's discretion, following technical interchange and coordination with the affected contractors. These modified requirements may be imposed on the VIIRS, the other sensor, or both. The other sensor need not be one addressed in this procurement.
SRDV3.2.1.1.1-3
Regardless of whether or not data are required from a non-VIIRS sensor, the VIIRS contractor shall be responsible for ensuring that the thresholds for the EDRs listed in this section are satisfied.
The VIIRS is referred to as the "primary" sensor suite or data source for the EDRs listed in this section, and these EDRs are referred to as the "primary" EDRs for the VIIRS.
Requirements for each of the primary EDRs are listed below and also in Appendix D. These requirements include maximum local average revisit time and maximum local refresh. These are system requirements and are to be met with a three ball system at 833 km altitude. The sensor contractor is not responsible for these system requirements. The sensor contractor is responsible for providing a sensor suite that has a swath width which will allow the system refresh and revisit requirements to be met when the sensor suite is flown on each of the three satellites in the system. The refresh and revisit times do, however, provide upper bounds on the time available for performing measurements between the generation of successive EDRs. These upper bounds are to be taken into account by the sensor contractor in formulating algorithms for the primary EDRs.
In the tables below only attributes that are numbered in the "Paragraph Number" column are VIIRS requirements. Attributes that are not numbered are provided for information only.
SRDV3.2.1.1.1-4
In addition to the explicit requirements given in Section 3.2.1.1.1 for each primary EDR, there may be derived EDR requirements associated with the satisfaction of thresholds for one or more other EDRs. If a derived requirement conflicts with an explicit requirement and/or another derived requirement, the most stringent requirement shall be satisfied.
Unless otherwise specified, attribute values are to be interpreted as upper bounds anywhere in the geographical 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.
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.
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).
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.
SRDV3.2.1.1.1-5
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 conditions are clear or cloudy.
SRDV3.2.1.1.1-6
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.
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.)
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.
SRDV3.2.1.1.1.1.1-1
Daytime and nighttime visible imagery shall be merged so as to minimize the apparent transition across the terminator. This requirement is in addition to the requirements to perform absolute radiometry in the visible bands entailed by the EDR requirements.
Unless otherwise specified, the explicit EDR requirements below apply to each spectral band that is required for the Application-Related requirements of Section 3.2.1.1.1.1.2 and at a minimum, to at least one daytime visible, one nighttime visible, and one IR channel (TBR).
Para. No. Thresholds Objectives
a. Horizontal Spatial
Resolution (HSR)
V40.2.3.1-2 1. Global, at nadir 1.0 km (TBD)
V40.2.3.1-3 2. Global, worst case 2.4 km 0.65 km
V40.2.3.1-4 3. Regional, at nadir 0.4 km (TBD)
V40.2.3.1-5 4. Regional, worst case 0.8 km 0.1 km
V40.2.3.1-6 5. Nighttime Visible, worst 2.6 km 0.65 km
case
V40.2.3.1-7 b. Horizontal Reporting Less than or Less than or
Interval equal to equal to
actual HSR actual HSR
(gapless or (gapless or
near gapless near gapless
coverage) coverage)
c. Horizontal Coverage
V40.2.3.1-8 1. Global (stored and Global Global
real-time)
V40.2.3.1-9 2. Regional, stored Up to 1/2 Up to 1/2
orbit, orbit,
non-contiguous, non-contiguous,
commandable commandable
by SOC; by SOC;
V40.2.3.1-1 3. Regional, real-time Global Global
0
d. Measurement Range
V40.2.3.1-1 1. Nighttime visible 4E-9 - 7E-4 Includes
1 W/cm2-sr in threshold
0.4-1.0 mm range; aurora
band, or & city lights
equivalent in don't saturate
another band imagery
V40.2.3.1-1 2. Other bands Derived Derived
2
V40.2.3.1-1 e. Measurement Uncertainty Derived Derived
3
f. Mapping Uncertainty
V40.2.3.1-1 1. At nadir 3 km (TBD)
4
V40.2.3.1-1 2. Worst case 4 km 0.5 km
5
g. Maximum Local Average 4 hrs (TBD)
Revisit Time
h. Maximum Local Refresh 6 hrs (TBD)
At any (TBD)
I. Fraction of Revisit Times location at
Less Than a Specified Value least 75% of
the revisit
times will be
4 hours or
less.
V40.2.3.1-1 Minimum Swath Width 3000 km (TBR) (TBR)
6
Application-Related Requirements (TBR)
The content and quality of the imagery shall be adequate to allow the following application-related requirements to be met. 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.
Manually generated cloud data are estimates of cloud cover and cloud type generated by a trained human analyst viewing the unprocessed and/or processed imagery derived from the unprocessed imagery, e.g., by data fusion, spatial rescaling, image enhancement, etc.
Cloud cover is defined as the fraction of a given area, i.e., of a horizontal cell, 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 minimum and maximum altitudes of this layer 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. For the purpose of validating this requirement, cloud cover estimates are to be generated by a trained 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
V40.2.3.2-1 1. Global 3 (TBR) times 2 times global
global HSR HSR
V40.2.3.2-2 2. Regional 3 (TBR) times 2 times
regional HSR regional HSR
V40.2.3.2-3 b. Horizontal Reporting Horizontal Horizontal
Interval cell size cell size
V40.2.3.2-4 c. Measurement Range 0 - 1, 0.1 0 - 1, 0.1
increments increments
V40.2.3.2-5 d. Measurement Uncertainty 0.1 0.1
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) in the 0.4-0.7 mm band (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) ) in the 0.4-0.7 mm band (TBR). Note that other EDRs require the type of non-cloud obscuration to be discerned and identified, e.g., smoke, dust, sand, ash, etc.
For the purpose of validating this requirement, typing is to be performed by a trained 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
V40.2.3.2.1.2- 1. Global (TBD) times 2 times
1 global HSR global HSR
V40.2.3.2.1.2- 2. Regional (TBD) times 2 times
2 regional HSR regional HSR
V40.2.3.2.1.2- b. Horizontal Reporting Horizontal cell Horizontal
3 Interval size cell size
V40.2.3.2.1.2- c. Measurement Range clear, clear,
4 obscured/not obscured/not
cloudy, ST, CU, cloudy, all
CI 18 cloud
types
d. Probability of
Correct Typing
V40.2.3.2.1.2- 1. Global 85 % 90 %
5
V40.2.3.2.1.2- 2. Regional 85 % 90 %
6
Sea ice data may be generated interactively by a trained 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
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
V40.2.3.2.2.1 a. Horizontal North of 36 deg North of 36 deg
-1 Coverage north latitude, north latitude,
south of 50 deg south of 50 deg
south latitude for south latitude for
sea ice. sea ice.
V40.2.3.2.2.1 b. Measurement Range Any latitude, Any latitude,
-2 longitude within longitude within
coverage domain coverage domain
c. Measurement
Uncertainty
V40.2.3.2.2.1 1. Global/Clear (TBD) (TBD)
-3
V40.2.3.2.2.1 2. Global/Cloudy (TBD) (TBD)
-4
V40.2.3.2.2.1 3. Regional/Clear (TBD) (TBD)
-5
V40.2.3.2.2.1 4. Regional/Cloudy (TBD) (TBD)
-6
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. For the purpose of verifying the measurement uncertainty requirement, the true value of the ice concentration in an area within the contours generated by the analyst is to be compared with the estimated value of ice concentration in this area. Errors in generating boundaries between regions having different ice concentrations (to the nearest 1/10) are ignored for the purpose of validating this requirement.
Units: Dimensionless
Para. No. Thresholds Objectives
V40.2.3.2.2. 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.
V40.2.3.2.2. b. Measurement 0 - 1, 0.1 increments 0 - 1, 0.1
2-2 Range increments
V40.2.3.2.2. c. Measurement 0.1 0.1
2-3 Uncertainty
Sea surface temperature (SST) is defined as the skin temperature of the of 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. No. Thresholds Objectives
a. Horizontal Cell Size
V40.2.4-1 1. Global, at nadir 3 km 1 km
V40.2.4-2 2. Global, worst case 4 km (TBD)
V40.2.4-3 3. Regional, at nadir 1 km 0.25 km
V40.2.4-4 4. Regional, worst case 1.3 km (TBD)
V40.2.4-5 b. Horizontal Reporting Local Local Horizontal
Interval Horizontal Cell Cell Size
Size
c. Horizontal Coverage
V40.2.4-6 1. Global Oceans Oceans
V40.2.4-7 2. Regional Oceans, up to Oceans, up to 1/2
1/2 orbit, orbit,
non-contiguous, non-contiguous,
commandable by commandable by
SOC; SOC;
V40.2.4-8 d. Measurement Range 271 K - 313 K 271 K - 313 K
V40.2.4-9 e. Measurement 0.5 K (TBR) 0.1 K
Uncertainty (TBR)
V40.2.4-10 f. Measurement Accuracy 0.2 K 0.1 K
V40.2.4-11 g. Measurement Precision (TBD) 0.1K
h. Mapping Uncertainty
V40.2.4-12 1. Global, at nadir 1 km 0.5 km
V40.2.4-13 2. Global, worst case 3 km (TBD)
V40.2.4-14 3. Regional, at nadir 1 km 0.1 km
V40.2.4-15 4. Regional, worst case 3 km (TBD)
i. Maximum Local Average 6 hrs 3 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.2.4-16 k. Minimum Swath Width 1700 km (TBR) (TBR)
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. No. Thresholds Objectives
a. Horizontal Cell Size
V40.2.6-1 1. Clear, at nadir (TBR) 1 km (TBD)
V40.2.6-2 2. Clear, worst case (TBR) 4 km 2 km
3. Cloudy, at nadir 40 km 2 km
4. Cloudy, worst case 50 km (TBD)
V40.2.6-3 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.2.6-4 c. Vertical Cell Size 0.1 cm 5 cm
V40.2.6-5 d. Vertical Reporting N/A (single 5 cm
Interval value
reported)
V40.2.6-6 e. Horizontal Coverage Land Land
V40.2.6-7 f. Vertical Coverage (TBR) surface to Surface to -80
-0.1 cm (skin cm
layer)
V40.2.6-8 g. Measurement Range 0 - 100 cm/m 0 - 100 cm/m
(TBR)
h. Measurement Uncertainty
V40.2.6-9 1. Clear, Bare soil in 1 0 cm/m (TBR) Surface: 1
regions with known soil cm/m
types (smaller horizontal Total 80 cm
cell size) column: greater
of 5% or 0.013
cm/m (130
gm/m3)
2. Cloudy , Bare soil in 20 cm/m (TBR) Surface: 1
regions with known soil cm/m
types (greater horizontal Total 80 cm
cell size) column: greater
of 5% or 0.013
cm/m (130
gm/m3)
V40.2.6-10 i. Mapping Uncertainty 3 km 1 km
j. Maximum Local Average 8 hrs 3 hrs
Revisit Time
k. Maximum Local Refresh (TBD) (TBD)
V40.2.6-11 l. Minimum Swath Width 3000 km (TBR) (TBR)
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).
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 mm 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
V40.3.1.1-1 a. Horizontal Cell Size 10 km 1 km
V40.3.1.1-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.3.1.1-3 c. Vertical Cell Size 30 km (Total 50 km
Column)
V40.3.1.1-4 1. 0 - 2 km N/A 0.25 km
V40.3.1.1-5 2. 2 - 5 km N/A 0.5 km
V40.3.1.1-6 3. > 5 km N/A 1 km
V40.3.1.1-7 d. Vertical Reporting N/A (Total Vertical cell
Interval Column) size
V40.3.1.1-8 e. Horizontal Coverage Global Global
V40.3.1.1-9 f. Vertical Coverage 0 - 30 km 0 - 50 km
V40.3.1.1-10 g. Measurement Range 0 - 2 0 - 10
h. Measurement Accuracy
V40.3.1.1-11 1. Over 0.03 (TBR) over 0.01
Ocean ocean, 0.1
V40.3.1.1-12 2. Over 0.2 (TBR) over
Land land
V40.3.1.1-13 i. Measurement Precision 0.03 0.01
V40.3.1.1-14 j. Long Term Stability 0.01 0.003
V40.3.1.1-15 k. Mapping Uncertainty 4 km 1 km
l. Maximum Local Average 6 hrs (TBR) 4hrs(TBR)
Revisit Time
m. Maximum Local Refresh (TBD) (TBD)
V40.3.1.1-16 n. Minimum Swath Width 3000 km (TBR) (TBR)
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 a, 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. No. Thresholds Objectives
V40.3.1.2-1 a. Horizontal Cell 10 km 1 km
Size
V40.3.1.2-2 b. Horizontal (TBD) (TBD)
Reporting Interval
V40.3.1.2-3 c. Vertical Cell Size 30 km (Total 50 km
Column)
V40.3.1.2-4 1. 0 - 2 km N/A 0.25 km
V40.3.1.2-5 2. 2 - 5 km N/A 0.5 km
V40.3.1.2-6 3. > 5 km N/A 1 km
V40.3.1.2-7 d. Vertical Reporting N/A (Total Column) Vertical cell
Interval size
V40.3.1.2-8 e. Horizontal Coverage Over ocean only Global
V40.3.1.2-9 f. Vertical Coverage 0 - 30 km 0 - 50 km
V40.3.1.2-10 g. Measurement Range -1 to +3 -2 to +4
V40.3.1.2-11 h. Measurement 0.3 over ocean 0.1
Accuracy
V40.3.1.2-12 i. Measurement 0.3 0.1
Precision
V40.3.1.2-13 j. Long Term Stability 0.1 0.03
V40.3.1.2-14 k. Mapping Uncertainty 4 km 1 km
l. Maximum Local 6 hrs 4 hrs(TBR)
Average Revisit Time
m. Maximum Local (TBD) (TBD)
Refresh
V40.3.1.2-17 n. Minimum Swath Width 3000 km (TBR) (TBR)
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
V40.3.1.3-1 a. Horizontal Cell Size 3 km 1 km
V40.3.1.3-2 b. Horizontal Reporting Local Local Horizontal
Interval Horizontal Cell Size
Cell Size
V40.3.1.3-3 c. Vertical Cell Size 30 km (Total 0.2 km
Column)
V40.3.1.3-4 d. Vertical Reporting N/A Vertical Cell
Interval Size
V40.3.1.3-5 e. Horizontal Coverage Global Global
V40.3.1.3-6 f. Vertical Coverage 0 - 30 km (TBD)
g. Measurement Range
V40.3.1.3-7 1. Type dust, sand, dust, sand, ash,
ash, other sea salt, smoke,
radioactive
smoke, other
V40.3.1.3-8 2. Concentration N/A 0 - 100 mg/m3
(smoke)
V40.3.1.3-9 h. Probability of (TBD) (TBD)
Correct Typing
V40.3.1.3-10 i. Measurement N/A (TBD)
Uncertainty
(concentration)
V40.3.1.3-11 j. Mapping Uncertainty 3 km 0.1 km
k. Maximum Local 12 hrs 3 hrs
Average Revisit Time
l. Maximum Local (TBD) (TBD)
Refresh
V40.3.1.3-12 m. Minimum Swath Width 3000 km (TBR) (TBR)
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.
V40.4.1-1 a. Horizontal Cell Size 25 km 10 km
V40.4.1-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.4.1-3 c. Horizontal Coverage Global Global
d. Vertical Cell Size N/A N/A
V40.4.1-4 e. Vertical Reporting Interval Total Column 0.25km
V40.4.1-5 f. Measurement Range 0 - 15 km 0 - 30 km
V40.4.1-6 g. Measurement Uncertainty 2 km (TBR) 0.25 km
V40.4.1-7 h. Mapping Uncertainty 4 km 1 km
i. Maximum Local Average 6 hrs 4 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.4.1-8 I. Minimum Swath Width 3000 km (TBR) (TBR)
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. No. Thresholds Objectives
V40.4.2-1 a. Horizontal Cell Size 25 km 2 km
V40.4.2-2 b. Horizontal Reporting (TBD) (TBD)
Interval
c. Vertical Cell Size N/A N/A
V40.4.2-3 d. Vertical Reporting Up to 4 layers 0.1 km
Interval
V40.4.2-4 e. Horizontal Coverage Global Global
V40.4.2-5 f. Vertical Coverage 0 - 20 km 0 - 30 km
V40.4.2-6 g. Measurement Range 0 - 1.0 0 - 1.0
V40.4.2-7 h. Measurement Accuracy 0.1 0.05
V40.4.2-8 i. Measurement Precision 0.15 0.025
V40.4.2-9 j. Mapping Uncertainty 4 km 1 km
k. Maximum Local Average 6 hrs 4 hrs
Revisit Time
l. Maximum Local Refresh (TBD) (TBD)
V40-4.2-10 m. Minimum Swath Width 3000 km (TBR) (TBR)
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.
V40.4.3-1 a. Horizontal Cell Size 50 km 10 km
V40.4.3-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.4.3-3 c. Vertical Cell Size Vertical Vertical
Reporting Reporting
Interval Interval
V40.4.3-4 d. Vertical Reporting 1.0 km(TBR) 0.3 km
Interval
V40.4.3-5 e. Horizontal Coverage Global Global
V40.4.3-6 f. Vertical Coverage 0 - 20 km 0 - 30 km
V40.4.3-7 g. Measurement Range 0 - 50 m (TBD)
V40.4.3-8 h. Measurement Accuracy greater of 10 % greater of 5 % or
or 4 m 2 m
V40.4.3-9 i. Measurement Precision greater of 5 % or 2 %
2 m
V40.4.3-1 j. Long Term Stability 2 % 1 %
0
V40.4.3-1 k. Mapping Uncertainty 4 km 1 km
1
l. Maximum Local Average 8 hrs 3 hrs
Revisit Time
m. Maximum Local Refresh (TBD) (TBD)
V40.4.3-1 n. Minimum Swath Width 3000 km (TBR) (TBR)
4
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. No. Thresholds Objectives
V40.4.6-1 a. Horizontal Cell Size 50 km 10 km
V40.4.6-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.4.6-3 c. Horizontal Coverage Global Global
V40.4.6-4 d. Measurement Range 0 - 10 optical (TBD)
depth
V40.4.6-5 e. Measurement Accuracy greater of 10 greater of 5 %
% and 0.05 and (TBD)
optical depth
V40.4.6-6 f. Measurement Precision greater of 5 % greater of 2 %
and 0.025 and (TBD)
optical depth
V40.4.6-7 g. Long Term Stability 2 % 1 %
V40.4.6-8 h. Mapping Uncertainty 4 km 1 km
i. Maximum Local Average 8 hrs 3 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.4.6-9 k. Minimum Swath Width 3000 km (TBR) (TBR)
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.
V40.4.7-1 a. Horizontal Cell Size 25 km 10 km
V40.4.7-2 b. Horizontal Reporting Interval (TBD) (TBD)
V40.4.7-3 c. Horizontal Coverage Global Global
d. Vertical Cell Size N/A N/A
V40.4.7-4 e. Vertical Reporting Interval Up to 4 0.25 km
layers
V40.4.7-5 f. Measurement Range 0 - 20 km (TBD)
g. Measurement Accuracy
V40.4.7-6 1. Cloud layer optical thickness > 1.0 km (TBR) 0.3 km
0.1(TBR)
V40.4.7-7 2. Cloud layer optical thickness 2 km 0.3 km
0.1(TBR)
V40.4.7-8 h. Measurement Precision 0.3 km 0.15 km
V40.4.7-9 i. Long Term Stability 0.2 km 0.1 km
V40.4.7-1 j. Mapping Uncertainty 4 km 1 km
0
k. Maximum Local Average Revisit 8 hrs 6 hrs
Time
l. Maximum Local Refresh (TBD) (TBD)
V40.4.7-1 m. Minimum Swath Width 3000 km (TBR)
1 (TBR)
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 highest altitude cloud layer is required. The objective is to report the cloud top pressure for all distinct cloud layers.
Units: mb
Para. No. Thresholds Objectives
V40.4.8-1 a. Horizontal Cell Size 15 km 10 km
V40.4.8-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.4.8-3 c. Horizontal Coverage Global Global
V40.4.8-4 d. Measurement Range 50 - 1050 mb (TBD)
e. Measurement Accuracy
V40.4.8-5 1. surface - 3 km 100 mb 30 mb
V40.4.8-6 2. 3 - 7 km 75 mb 22 mb
V40.4.8-7 3. > 7 km 50 mb 15 mb
f. Measurement Precision
V40.4.8-8 1. surface - 3 km 50 mb 10 mb
V40.4.8-9 2. 3 - 7 km 38 mb 7 mb
V40.4.8-10 3. > 7 km 25 mb 5 mb
g. Long Term Stability
(TBR)
V40.4.8-11 1. surface - 3 km 10 mb 3 mb
V40.4.8-12 2. 3 - 7 km 7 mb 2 mb
V40.4.8-13 3. > 7 km 5 mb 1 mb
V40.4.8-14 h. Mapping Uncertainty 4 km 1 km
i. Maximum Local Average 8 hrs 3 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.4.8-15 i. Minimum Swath Width 3000 km (TBR) (TBR)
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 Objectives
No.
V40.4.9-1 a. Horizontal Cell Size 25 km 10 km
V40.4.9-2 b. Horizontal Reporting Interval (TBD) (TBD)
V40.4.9-3 c. Horizontal Coverage Global Global
V40.4.9-4 d. Measurement Range 180 - 310 K (TBD)
e. Measurement Accuracy
V40.4.9-5 1. Cloud layer optical 3 K 1.5 K
thickness > 0.1 (TBR)
V40.4.9-6 2. Cloud layer optical 6 K (TBD)
thickness 0.1 (TBR)
V40.4.9-7 f. Measurement Precision 1.5 K 0.5 K
V40.4.9-8 g. Long Term Stability 1 K 0.1 K
V40.4.9-9 h. Mapping Uncertainty 4 km 1 km
i. Maximum Local Average Revisit 6 hrs 6 hrs
Time
j. Maximum Local Refresh (TBD) (TBD)
V40.4.9-1 k. Minimum Swath Width 3000 km (TBR)
2 (TBR)
Surface albedo is defined as the amount of visible solar radiation (0.4 - 0.7 µm) reflected by the earth's surface into an upward hemisphere (sky dome) divided by the amount incident from this hemisphere.(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.
V40.5.2-1 a. Horizontal Cell Size 4 km 0.5 km
V40.5.2-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.5.2-3 c . Horizontal Coverage Global Global
V40.5.2-4 d. Measurement Range 0 - 1.0 0 - 1.0
V40.5.2-5 e. Measurement Accuracy 0.05 0.0125
V40.5.2-6 f. Measurement Precision 0.02 0.01
V40.5.2-7 g. Long Term Stability 0.02 0.01
V40.5.2-8 h. Mapping Uncertainty 4 km 1.0 km
i. Maximum Local Average 24 hrs 4 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.5.2-9 k. Minimum Swath Width 3000 km (TBR) (TBR)
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. No. Thresholds Objectives
V40.6.1-1 a. Horizontal Cell Size 4 km 1 km
V40.6.1-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.6.1-3 c. Horizontal Coverage Land Land
V40.6.1-4 d. Measurement Range 213 K - 343 K 213 K - 343 K
V40.6.1-5 e. Measurement Accuracy 2.5 K 1 K
V40.6.1-6 f. Measurement Precision 0.5 K 0.025 K
V40.6.1-7 g. Mapping Uncertainty 4 km 1 km
h. Maximum Local Average 6 hrs 3 hrs
Revisit Time
i. Maximum Local Refresh (TBD) (TBD)
V40.6.1-8 j. Minimum Swath Width 1700 km (TBR) (TBR)
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. No. Thresholds Objectives
V40.6.2-1 a. Horizontal Cell Size 4 km 1 km
V40.6.2-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.6.2-3 c. Horizontal Coverage Land (TBD)
V40.6.2-4 d. Measurement Range -1 to +1 NDVI -1 to +1
units
V40.6.2-5 e. Measurement Accuracy 0.05 NDVI units 0.03 NDVI
units
V40.6.2-6 f. Measurement Precision 0.04 NDVI units 0.02 NDVI
units
V40.6.2-7 g. Long Term Stability 0.04 NDVI units 0.04 NDVI
units
V40.6.2-8 h. Mapping Uncertainty 4 km 1 km
i. Maximum Local Average 24 hrs 24 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.6.2-9 k. Minimum Swath Width 3000 km (TBR) (TBR)
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. No. Thresholds Objectives
a. Horizontal Cell Size
(TBR)
V40.6.3-1 1. Clear - daytime 1.3 km 1 km
2. Cloudy and/or nighttime 12.5 km 1 km
V40.6.3-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.6.3-3 c. Snow Depth Ranges > 0 cm (Any Snow > 8 cm, > 15
Thickness) cm, > 30 cm,
>51 cm, >76 cm
V40.6.3-4 d. Horizontal Coverage Land Land & Ice
V40.6.3-5 e. Vertical Coverage 0 - 40 cm 0 - 1 m
V40.6.3-6 f. Measurement Range 0 - 1 0 - 1 per snow
depth category
g. Measurement
Uncertainty(TBR)
V40.6.3-7 1. Clear - daytime 10% (snow/no 10% for snow
snow) depth
V40.6.3-8 2. Cloudy and/or nighttime 20% (snow/no TBD
snow)
h. Mapping Uncertainty
V40.6.3-9 1. Clear 2 km 1 km
2. Cloudy 7 km 1 km
i. Maximum Local Average 12 hrs 3 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.6.3-10 m. Minimum Swath Width 3000 km (TBR) (TBR)
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. No. Thresholds Objectives
a. Horizontal Cell Size
V40.6.4-1 1. Global 20 km 1 km
V40.6.4-2 2. Regional 20 km 0.25 km
V40.6.4-3 b. Horizontal Reporting (TBD) (TBD)
Interval
c. Horizontal Coverage
V40.6.4-4 1. Global Land Land
V40.6.4-5 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
V40.6.4-6 1. Vegetation/surface type 21 types 21 types
specified specified
above above
V40.6.4-7 2. Vegetation cover N/A 0 - 100 %
V40.6.4-8 e. Measurement Accuracy N/A 2 %
(veg. cover)
V40.6.4-9 f. Measurement Precision N/A 0.1 %
(veg. cover)
V40.6.4-10 g. Correct Typing 70 % (TBD)
Probability (vegetation
/surface type)
V40.6.4-11 h. Mapping Uncertainty 5 km 1 km
i. Maximum Local Average 24 hrs 3 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.6.4-12 k. Minimum Swath Width 3000 km (TBR) (TBR)
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. No. Thresholds Objectives
a. Horizontal Cell Size
V40.7.1-1 1. Global 4 km 1 km
V40.7.1-2 2. Regional (Coastal) 1.3 km 0.25 km
V40.7.1-3 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.1-4 c. Vertical Cell Size(TBR) 5 m 1 m
V40.7.1-5 d. Vertical Reporting Vertical Cell Vertical Cell
Interval Size Size
e. Horizontal Coverage Oceans Oceans
V40.7.1-6 1. Global Oceans, > 370 Oceans, > 370
km from km from
coastline coastline
V40.7.1-7 2. Regional (Coastal) Oceans, 370 Oceans, 370
km from km from
coastline coastline
V40.7.1-8 f. Vertical Coverage 0 to -10 m 0 to -30 m
g. Measurement Range
V40.7.1-9 1. Speed 0 - 5 m/s 0 - 5 m/s
V40.7.1-10 2. Direction 0 - 360 deg 0 - 360 deg
h. Measurement
Accuracy(TBR)
V40.7.1-11 1. Speed 0.25 m/s 0.1 m/s
V40.7.1-12 2. Direction 15 deg 5 deg
i. Measurement
Precision(TBR)
V40.7.1-13 1. Speed 0.25 m/s 0.1 m/s
V40.7.1-14 2. Direction 15 deg 5 deg
V40.7.1-15 j. Mapping Uncertainty 3 km 1 km
k. Maximum Local Average (TBD) 12 hrs
Revisit Time
l. Maximum Local Refresh (TBD) (TBD)
V40.7.1-16 m. Minimum Swath Width 1700 km(TBR) (TBD)
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. No. Thresholds Objectives
a. Horizontal Cell Size
V40.7.2-1 1. Regional, nadir 4 times 0.4 km (TBD)
(TBR)
V40.7.2-2 2. Regional, worst 4 times 0.8 km 0.65 km
case (TBR)
V40.7.2-3 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.2-4 c. Horizontal Coverage Fresh Water Fresh Water
Up to 1/2 Up to 1/2
orbit, orbit,
non-contiguous, non-contiguous,
commandable commandable
by SOC by SOC
V40.7.2-5 d. Measurement Range 1/10 to 10/10 0/10 to 10/10
concentration concentration
e. Measurement Uncertainty
V40.7.2-6 1. Ice Edge 10 km 5 km
Boundary(TBS)
V40.7.2-7 2. Ice Concentration 20 % or 1/10 10 %
V40.7.2-8 f. Mapping Uncertainty 3 km 1 km
g. Maximum Local Average 12hrs 6hrs
Revisit Time
h. Maximum Local Refresh (TBD) (TBD)
V40.7.2-9 i. Minimum Swath Width 3000 km(TBR) (TBD)
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.
V40.7.3-1 a. Horizontal Cell Size 30km 10km
V40.7.3-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.3-3 c. Horizontal Coverage Ice-covered Ice-covered
land/water land/water
V40.7.3-4 d. Measurement Range 213 K - 293 K (TBD)
V40.7.3-5 e. Measurement Uncertainty 1 K (TBD)
V40.7.3-6 f. Mapping Uncertainty 3 km 1 km
g. Maximum Local Average 24 hrs 12 hrs
Revisit Time
h. Maximum Local Refresh (TBD) (TBD)
V40.7.3-9 i. Minimum Swath Width 1700 km (TBR) (TBD)
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. No. Thresholds Objectives
V40.7.4-1 a. Horizontal Cell Size 1.3 km (TBR) 0.1 km (TBR)
V40.7.4-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.4-3 c. Horizontal Coverage Rivers, ocean Rivers, ocean
coastal coastal
regions regions
V40.7.4-4 d. Measurement Range (TBD) (TBD)
V40.7.4-5 e. Measurement Accuracy greater of 30 greater of 15
% and (TBD) % and (TBD)
V40.7.4-6 f. Measurement Precision greater of 40 greater of 15
% and (TBD) % and (TBD)
V40.7.4-7 g. Mapping Uncertainty 3 km 0.1 km
h. Maximum Local Average 48 hrs 12 hrs
Revisit Time
i. Maximum Local Refresh (TBD) (TBD)
V40.7.4-8 j. Minimum Swath Width 1700 km(TBR) (TBD)
Net heat flux refers to net surface flux of heat 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. No. Thresholds Objectives
V40.7.5-1 a. Horizontal Cell Size 20 km 5 km
V40.7.5-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.5-3 c. Horizontal Coverage Oceans Oceans
V40.7.5-4 d. Measurement Range(TBR) 0 - 1000 W/m2 0 - 2000 W/m2
V40.7.5-5 e. Measurement Accuracy 10 W/m2 1 W/m2
V40.7.5-6 f. Measurement Precision 5 W/m2 1 W/m2
V40.7.5-7 g. Mapping Uncertainty 7 km (TBD)
h. Maximum Local Average 6 hrs 3 hrs
Revisit Time
i. Maximum Local Refresh (TBD) (TBD)
V40.7.5-8 j. Minimum Swath Width 3000km(TBR) (TBD)
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
V40.7.6-1 1. Global, worst case 2.6 km 1 km
V40.7.6-2 2. Regional (Coastal), worst 1.3 km 0.1 km
case
V40.7.6-3 b. Horizontal Reporting (TBD) (TBD)
Interval
c. Horizontal Coverage Oceans Oceans
V40.7.6-4 1. Global > 370 km from > 370 km from
coastline coastline
V40.7.6-5 2. Regional (Coastal) 370 km from 370 km from
coastline coastline
V40.7.6-6 d. Measurement Range 0.05 - 50 0 - 100 mg/m3
mg/m3
V40.7.6-7 e. Measurement Accuracy The > of 30 % The > of 30 %
or TBD mg/m3 or TBD mg/m3
V40.7.6-8 f. Measurement Precision The > of 20 % The > of 10 %
or TBD mg/m3 or TBD mg/m3
g. Mapping Uncertainty
V40.7.6-9 1. Global 3 km 0.5 km
V40.7.6-1 2. Regional 3 km 0.1 km
0
h. Maximum Local Average 48 hrs 12 hrs
Revisit Time
i. Maximum Local Refresh (TBD) (TBD)
V40.7.6-1 j. Minimum Swath Width 1700 km (TBR) (TBD)
1
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. No. Thresholds Objectives
V40.7.8-1 a. Horizontal Cell Size 3 km 0.1 km
(Ice Age)
V40.7.8-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.8-3 c. Horizontal Coverage Oceans Oceans
d. Measurement Range
V40.7.8-4 1. Ice Age Classes
First Year, New, Young,
Multi-year First Year,
(TBR) and Old (TBR)
V40.7.8-5 2. Ice Motion 0 - 50 km/day 0 - 50 km/day
V40.7.8-6 e. Probability of Correct 70 % 90 %
Typing (Ice Age)
V40.7.8-7 f. Measurement Uncertainty 1 km/day 0.1 km/day
(Ice motion)
V40.7.8-8 g. Mapping Uncertainty 3 km 1 km
h. Maximum Local Average 24 hrs 12 hrs
Revisit Time
i. Maximum Local Refresh (TBD) (TBD)
V40.7.8-9 j. Minimum Swath Width 3000 km (TBR) (TBD)
Mass Loading (TBR) (IORD Title - Turbidity)
Mass Loading is defined as the concentration of suspended matter in a vertical column in the ocean, This quantity is referred 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. No. Thresholds Objectives
V40.7.11-1 a. Horizontal Cell Size 1.3 km 0.25 km
V40.7.11-2 b. Horizontal Reporting (TBD) (TBD)
Interval
V40.7.11-3 c. Horizontal Coverage Oceans Oceans
V40.7.11-4 d. Vertical Cell Size Surface layer (TBD)
((TBD) m)
V40.7.11-5 e. Measurement Range (TBD) 0 - 100 mg/l
V40.7.11-6 f. Measurement Accuracy greater of 30 0.1 mg/l
% and (TBD)
V40.7.11-7 g. Measurement Precision (TBD) 0.1 mg/l
V40.7.11-8 h. Mapping Uncertainty (TBD) 0.5 km
i. Maximum Local Average 48 hrs 24 hrs
Revisit Time
j. Maximum Local Refresh (TBD) (TBD)
V40.7.11-9 k. Minimum Swath Width 1700 km (TBR) (TBD)
Modifications and Clarifications of EDR Requirements
The modifications and clarifications of EDR requirements in section 3.2.1.1.23.2.1.1.2 take precedence over any conflicting requirements or statements in section 3.2.1.1.13.2.1.1.1, Appendix D of this SRD, the TRD, or the IORD.
SRDV3.2.1.1.2.1-1
Requirements for the following EDRs shall be fully met under clear conditions, but need not be fully met under cloudy conditions using sensing data from the VIIRS alone:
Definitions of "clear" and "cloudy" appear in Section 40.1.8.1 of Appendix D, for guidance purposes. The definition of "detectable cloud," to which the term "cloud" always refers in this document, is in the Glossary in Appendix A.
SRDV3.2.1.1.2.1-2
The contractor shall recommend definitions of "clear" and "cloudy". Different definitions may be proposed for different EDRs.
Under cloudy conditions these EDRs should be provided on an as capable basis, possibly with degraded data quality and completeness. In particular, the Aerosol Optical Thickness, Aerosol Particle Size Parameter, and Suspended Matter EDRs should be provided above the clouds under cloudy conditions using VIIRS sensing data.
SRDV3.2.1.1.2.2-1
Requirements for the following EDRs shall be fully met under daytime conditions, and should be fully or partially met under non-daytime conditions, if feasible, using sensing data from the VIIRS alone:
SRDV3.2.1.1.2.2-2
The contractor shall determine the radiance levels in appropriate bands that will define "daytime conditions" for each of these EDRs. Daytime conditions need not be defined in the same way for different EDRs.
Under non-daytime conditions these EDRs should be provided on an as capable basis, possibly with degraded data quality and completeness.
Operational SDR Requirements [TBR]
In processing RDRs into EDRs the IDPS will generate intermediate-level satellite instrument data files, including Sensor Data Records (SDRs). SDRs are needed for retrospective processing, leading to improved methods, and for archival, for long-term sensor evaluation or troubleshooting. SDRs will be delivered to the same user destinations as the associated EDRs, as specified in the EDR/RDR matrix (Appendix E), which lists delivery destinations of RDRs/EDRs. The generation and delivery of operational SDRs will be the responsibility of the IDPS (TSPR) contractor, not the VIIRS contractor.
At a minimum, operational SDRs will include the following information:
The IDPS (TSPR) contractor, not the VIIRS contractor, will be responsible for defining the content of operational SDRs.
The VIIRS contractor may recommend the content of operational SDRs. The government, at its discretion, may provide this recommendation to the IDPS (TSPR) contractor.
SRDV3.2.1.2.1-1
The VIIRS contractor shall participate in technical interchange meetings with the IDPS (TSPR) contractor to support the definition of the operational SDRs with respect to both content and format, if so requested by the government.
The VIIRS contractor will determine the content of non-operational SDRs generated by the contractor for requirements validation purposes.
The IDPS (TSPR) contractor, not the VIIRS contractor, will be responsible for defining the format of operational SDRs.
The VIIRS contractor may recommend the format of operational SDRs. The government, at its discretion, may provide this recommendation to the IDPS (TSPR) contractor.
The VIIRS contractor will determine the format of non-operational SDRs generated by the contractor for requirements validation purposes.
Operational RDR Requirements [TBR]
Since RDRs are processed into EDRs, RDRs are considered to have met their requirements when they are of an appropriate format, completeness, and quality to be adequately processed into their associated EDRs.
SRDV3.2.1.3-1
The VIIRS contractor shall be responsible for generating operational RDRs.
SRDV3.2.1.3.1-1
At a minimum, operational RDRs shall include the following data:
SRDV3.2.1.3.1-2
The following data, at a minimum, shall be appended to or incorporated in an operational RDR at least every five minutes:
SRDV3.2.1.3.2-1
The contractor shall determine the RDR format for each mode within the packet envelopes.
SRDV3.2.1.4-1
The VIIRS shall be designed so that with scientific geolocation algorithms (adopted, adapted, or developed by the contractor) the mapping uncertainty requirements of all primary EDRs will be met. Spacecraft and spacecraft/payload interface characteristics which contribute to geolocation errors are specified in Section 3.2.4.2.1.3.
SRDV3.2.1.4-2
The contractor shall recommend sensor requirements necessary to meet the mapping uncertainty requirements of the primary EDRs.
SRDV3.2.1.5.1-1
The contractor shall adopt or adapt existing algorithms or develop new scientific algorithms for all primary EDRs. (See Section 3.2.1.1.1.) Adopting an algorithm means using an existing algorithm without change. Adapting an algorithm means using an existing algorithm with some modification, such as different values of coefficients, inclusion of higher order corrections, fusion of additional data sources, etc.
SRDV3.2.1.5.1-2
The contractor shall also adopt or adapt existing algorithms or develop new scientific algorithms for all intermediate level data products used to generate the primary EDRs, such as SDRs and flags indicating data quality, daytime versus nighttime, clear versus cloudy, etc. Since the VIIRS contractor is not responsible for the content or format of operational SDRs, the VIIRS contractor may select the appropriate intermediate-level data products needed as inputs to his scientific EDR algorithms in satisfying this requirement. The description of operational SDRs in Section 3.2.1.23.2.1.2 is provided as guidance. Algorithms need not be provided for data products that are generated by other sensor suites and utilized as inputs to the algorithms for VIIRS primary EDRs.
SRDV3.2.1.5.2-1
The performance of the scientific EDR algorithms delivered by the VIIRS contractor shall meet EDR thresholds and shall be no worse than the performance of algorithms utilized for current (TBR) operational data products for these EDRs, if such operational products exist.
Operational Algorithm Teams (OATs)
The government's Operational Algorithm Teams (OATs) may recommend scientific algorithms. These teams have contributed to the definition of the instrument requirements of Section 3. The OATs may also provide advisory information on VIIRS functional and calibration requirements.
The government considers the SDR and EDR algorithms adopted, adapted, or developed by the VIIRS contractor to be scientific, rather than operational, algorithms. The VIIRS contractor is not responsible for identifying or developing operational SDR and EDR algorithms for the VIIRS. (Any operational algorithms necessary for the generation of RDRs will ultimately be the responsibility of the VIIRS contractor, and the operational code implementing these algorithms will be part of the required flight software. This statement applies to the post-downselect phase of the VIIRS program.)
SRDV3.2.1.5.4-1
The scientific SDR and EDR algorithms delivered by the VIIRS contractor shall be convertible into operational code that is compatible with a 20 minute maximum processing time at either the DoD Centrals or DoD field terminals for the conversion of all pertinent RDRs into all required EDRs for the site or terminal, including those based wholly or in part on data from other sensor suites. The intent of this requirement is to preclude algorithms that are so computationally intensive that any foreseeable implementation would stress or exceed the time available for delivery of EDRs in an operational environment.
SRDV3.2.1.5.4-2
The means by which the contractor shall validate the requirement that scientific algorithms be convertible to operational code subject to the constraint specified in SRDV3.2.1.5.4-1 is TBR.
SRDV3.2.1.5.4-3
The availability of any inputs required from data bases or other ancillary sources to generate data products shall also be adequate to allow EDRs to be generated at the DoD Centrals and DoD field terminals within the time constraint specified in SRDV3.2.1.5.4-1.
SRDV3.2.1.5.5-1
The contractor shall identify any constraints on the relationships between sensors within VIIRS (if VIIRS is comprised of more than one sensor) or between sensors in different sensor suites that are entailed by the contractor's algorithms for the VIIRS primary EDRs which require data from multiple sensors. Such constraints might include, for example, relative pointing knowledge, relative pointing accuracy, co-boresighting, synchronization, etc. Based on this information and the corresponding information from other sensor contractors, the government may impose modified or additional requirements on the VIIRS and/or other sensor suites. (See Sec. 3.2.2.)
The NPOESS IPO will provide up to 5 images in each of the 44 (TBR) categories/areas listed below for use in developing sensor designs, and in verifying sensor and algorithm performance. The government will create an additional set of up to 5 images in each area/category which will be used by the government to determine sensor design performance and algorithm performance.
Terrain areas and categories for standard scenes (TBR). There are 24 areas in all. For each area except polar, there will be day and night categories as well, making the total 44 areas / categories of standard datasets. The areas will all be 360 km X 360 km (3.25 X 3.25) anchored at the NW corner identified above.
Location
Climate Area Spring Summer Autumn Winter (NW Corner)
Polar
Land: Siberia X X 70N 103E
Coast: Point Barrow X X 72N 159W
Tropics
Land: Amazon Basin X X 5S 65W
Coast: Cameroon X X 5N 8E
Ocean: E. Pacific X 8N 120W
Midlatitudes
Land: W. Urals X X X X 56N 56E
Coast: Olympic X X X X 48N 126W
Peninsula X X X X 41N 118W
Desert: Great Basin X 45N 30W
Ocean: Azores X 48N 8E
Alpine: Swiss Alps X 25N 88E
Sub-Tropical: Bangladesh
Images will have a ground sample distance (GSD) of 200m (TBR) and will include 1800X1800 (TBR) GSD elements (pixels). These images will represent top of the atmosphere radiance in-band, with bands selected by the contractor to match their sensor bands. The number of image channels modeled will not exceed 15. Contractors with more than 15 channels in their design must select which 15 channels they desire as standard scenes. After delivery of the initial set of images, contractors may request copies of the executable models and the input datasets and commands used to create the images if they wish to generate additional scenes in other channels. Sensor relative spectral responsivity will be assumed to be a top-hat (TBR), since alternate sensor response functions can be characterized and calibrated out.
Terrain data underlying the images will be constructed from Landsat Thematic Mapper data taken from 2X3 contiguous mosaics of cloud free collections (TBR). Clouds will be inserted into the images using a TBS technique. Top of the atmosphere radiance values will be computed using MODTRAN v 3.0. Image files will be supplied as binary data in raster format, with a 32 bit floating point value for each pixel, and with 1 band per file (TBR). Files will be supplied on Tape Archives (TAR) tapes (TBR).
SRDV3.2.1.7-1
The VIIRS shall create real-time data packets for transmission to the ground in the real-time data links (LDR, HDR ) and transmit them to the spacecraft data handler. (TBR)
The VIIRS shall create two types of data packets for transmission to the spacecraft storage system:(1) a global resolution and (2) a regional resolution data packet. (TBR)
Data Formatting and Compression (TBR)
SRDV3.2.1.9-1
The data packets generated by the VIIRS shall conform to the Consultative Committee for Space Data Systems (CCSDS) packetization per the (TBS) real-time interface specification and the (TBS) stored-data interface specification.
SRDV3.2.1.9-2
If data compression techniques are utilized by the VIIRS in generating data packets for storage on orbit, the compression shall be lossless.
SRDV3.2.1.9-3
The VIIRS may utilize lossy data compression in generating data packets for real time transmission of mission data to field terminals via either high or low data rate links, with the exception of sensor calibration data.
SRDV3.2.1.9-4
If the VIIRS utilizes data compression techniques in generating data packets for real time transmission of sensor calibration data to field terminals via either high or low data rate links, the compression shall be lossless.
SRDV3.2.1.9-5
The VIIRS contractor shall identify and quantify any EDR performance degradation at the field terminals resulting from the use of lossy data compression.
Scan Requirements [TBD]
"Scan type" refers to the geometrical mode in which the scene is scanned, e.g., whiskbroom, pushbroom, cross-track, conical, etc. The scan type should be the same for all instruments in the suite.
The swath width should be the same for all instruments in the suite to facilitate synergistic use of data from different instruments.
Scan-to-scan Separation (overlap/underlap at nadir) [TBD]
SRDV3.2.1.18-1
The VIIRS shall perform periodic autonomous or ground controlled mission sensor calibration as required.
Constraints on relationships between different sensor suites or different sensors within the VIIRS suite entailed by the primary VIIRS EDR algorithms are included in this section. (See Section 3.2.1.5.53.2.1.5.5.)
The system interfaces relevant to the sensors are depicted in Figure 3.2.3 below.
Figure 3.2.3 Partial System Internal Interfaces
Physical and Interface Characteristics
Mass, dimensions, power, and data rates specified herein are nominal values (with contingency) which were developed during initial studies at the Integrated Program Office. All values are TBR, indicating that specific allocations are negotiable. It is presently planned that definitive allocations will be defined by the IPO, in consultation with sensor contractors, by the time of the SRR. In the interim, contractors should keep in mind that relaxation from nominal allocations will only be possible if changes are consistent with the requirement to accommodate the full NPOESS payload suite of instruments on a spacecraft which can be placed into a nominal 833 km orbit by an EELV class launch vehicle.
SRDV3.2.4-1
The mass of the VIIRS sensor shall be less than or equal to 132 kilograms (TBR).
SRDV3.2.4-2
The dimensions of the VIIRS sensor shall be less than or equal to the following limits:
Dimensions of components mounted internal to the spacecraft bus are TBD.
SRDV3.2.4-3
The power consumption (orbit average) of the VIIRS sensor shall be less than or equal to 215 Watts (TBR).
SRDV3.2.4-4
The data rate (orbit average) of the VIIRS sensor shall be less than or equal to the following limits:
Continued in File VIIRS-B.DOC