The radar sensors programs directly support JWS&T areas Dominant Battlespace Knowledge, Precision Force, Combat Identification and Joint Theater Missile Defense Capabilities by offering potential for "near-perfect", real-time knowledge of the enemy; to engage regional forces promptly in decisive combat, on a global basis; and to counter the threat of future ballistic and cruise missiles. Important objectives include near-leak-proof theater and ballistic missile defense; heightened ability (30 dB improvement) to detect low-RCS targets using Surface Based and Airborne WAS sensors; breakthrough capabilities to detect and classify foliage-concealed, time-critical targets as well as underground targets; development of affordable hardware (<$200K/copy) to provide decisive target acquisition/fire control capabilities for armored vehicles and an increase in radar instantaneous bandwidth (to 1 Ghz and beyond) to achieve improved Combat ID (target classification/identification) and tracking. Combat Identification (CID) provides for efficient accomplishment of the military objectives while minimizing fratricide. An effective CID capability must provide the required friend/hostile/neutral identification information at ranges compatible with the range of each platform's weapon. Service requirements for radar are moving beyond detection to target classification. This requirement for the Combat ID and automatic target recognition is now driving radar performance to high resolution, precisely registered n-dimensional measurement capability. Since cost reduction is an important aspect of all new DoD systems, significant use of Commercial Off-The-Shelf (COTS) equipment and novel Electronically Scanned (ESCAN) Antenna designs are being pursued. The Mountaintop Radar and the UHF/L Band Array Technology are targeted for transition to upgrades to the Navy E-2C and to the Air Force E-3 radars. The associated Space Time Adaptive Processing Algorithms, will have application to all airborne radars where nulling of clutter and jamming is required. The GBR Solid State Demo will be a major contributor to the National Missile Defense System. The low-frequency UWB radar and the Concealed Target Detection (CTD) algorithm programs lead to required capabilities in battlefield surveillance from platforms such as UAVs. Battlefield radar efforts provide upgrades to the Longbow Apache Fire Control Radar (FCR) as well as optimizing the specifications for the Comanche FCR system. The High Frequency (HF) Surface Wave and Ultra Wide Band (UWB) Technology are planned for transition to improve/upgrade the Navy's Surface Fleet Surveillance and Over-The-Horizon (OTH) Targeting Capabilities. Programs must demonstrate the benefits of combining radar and EO Sensors for significantly improving long-range, near all-weather, surveillance and target acquisition capability.

3.1.2 Radar Overview

3.1.2.1 Goals and Timeframes. The radar sensor can provide an all-weather, long-range detection, location and recognition of significant military targets capability. However, continued technology development is required to meet the needs of the warfighter. The goals of the Radar program are described below.

Meeting these goals depends on advances in ATR (3.3), RF Components (3.6) Microelectronics (3.8), Electronic Materials (3.9) and Electronics Integration (3.10), as well as, understanding the Battlespace Environments (3.11, 3.13, 3.14).

3.1.2.2 Major Technical Challenges. The major technical challenge is to improve the capability of Radar Sensors while maintaining or reducing their size and weight, and significantly improve affordability, especially in an environment of declining quantities of weapons systems platform integration opportunities, hence sensor production base. For both imaging and non-imaging radars, advanced signal processing algorithms will be developed to address major challenges presented by clutter jamming and reduced cross-section targets and COTS hardware will be fully leveraged improve affordability. For multimode radars, the technical challenge is improved performances in all types of interference while at the same time maintaining affordability and minimizing radar cross-section of the sensor integrated onto its platform.

3.1.2.3 Related Federal and Private Sector Efforts. Advanced radar sensors are primarily developed for Government applications. Data from airborne space-based efforts are relevant to NASA and NOAA research efforts in weather detection, global change, atmospheric remote sensing, astronomy/astrophysics and orbital debris tracking along with numerous private sector spacecraft programs. Surface and airborne radar technology is applicable to the Department of Transportation, local and federal law enforcement agencies, the medical community and with multiple organizations for humanitarian purposes (i.e., search and rescue, buried mine and tunnel detection).

3.1.3 S&T Investment Strategy

The S&T Investment Strategy continues to focus on core technology development thrust areas that lead to Advanced Technology Demonstrations (ATDs) which, in turn, enables Advanced Concept Technology Demonstrations (ACTDs). Appropriate technology investments from other Government departments and agencies are incorporated. Particular emphasis is focused on affordability and integrated multi-sensor approaches.

3.1.3.1 Technology Demonstrations

3.1.3.1.1 Multi-Mission UAV Sensor ATD. DTO SE.01.01.ANF. An affordable, lightweight, multi-function radar will be built leveraging MIMIC technology for size and weight reduction and incorporate COTS signal processor for cost reduction. The ATD demonstrates an affordable, lightweight (60 pound), multi-function radar that will provide the battlefield commander with a continuous, real-time, all-weather capability to detect, locate and identify high-priority fixed and mobile targets in all theaters of operation.

3.1.3.1.2 Smart Skins Array ATD. DTO SE.02.02.N This ATD demonstrates the technical feasibility, operational utility and support benefits of structurally embedded antenna arrays for the F/A-18. A leading edge embedded array will be demonstrated on an F/A-18 in FY 97.

3.1.3.1.3 High Frequency Surface Wave Radar (HFSWR) ATD. This ATD addresses DTO SE.03.02.N. The HFSWR will provide OTH, critical early warning (30 sec for M2.0 target) of low flying missiles and cue weapon engagement radars. Performance improvement goals include detection of supersonic sea skimming missiles at 2.5X the range currently achievable with a microwave radar with a better than 1.0 degree azimuth tracking accuracy.

3.1.3.1.4 Cruise Missile Defense (CMD) Phase II Technology Demonstration. The CMD phase II technology demonstration, DTO D07, is a follow-on to the joint Army-Navy CMD phase I ACTD, DTO DO6 (Mountaintop,) completed in February 1996. The CMD phase II will move the surveillance and fire control functions off the mountain and into an airborne platform. The focus will be on OTH detection and track of land and sea launched cruise missiles from airborne sensors and will enable surface-based air defense systems to engage there targets at ranges well beyond their radar horizon.

3.1.3.1.5 Combat ID. DTO C05. The joint Combat ID ACTD has been designed to demonstrate integrated air-to-ground and ground-to-ground combat identification capability. The approach employs an integrated CID architecture which combines data links with cooperative and non-cooperative identification capabilities. The resultant platform CID capabilities will be achieved by combining onboard data from multiple sensors and systems with indirectly-supplied off-board information. The ACTD will quantify the contributions of identification technologies in reducing fratricide and increasing combat effectiveness. The ACTD will refine inter/intra service tactics, techniques and procedures. Specific technologies included in the ACTD are: enhanced BCIS with a digital data link, a BCIS pod for fixed wing and rotary wing aircraft for point of engagement friend ID; enhanced forward air controller capability with integrated BCIS and Situation Awareness Data Link (SADL); modified SINCGARS SIP radios that will provide automatic target location query for friend ID; and situation awareness data from the digitized battlefield delivered to the gunner's sight.

3.1.3.2 Technology Development

3.1.3.2.1 Penetrating/Identification Radar. DTO SE.04.01.ANFE. The Penetrating/Identification radar technology improves the warfighting capability through the development of ultra-wideband and narrow band radars and demonstration of radiometric technology that detects and identifies tactical targets hidden in foliage, buildings, or beneath the ground in real-time. Technology demonstrations will provide advances in clutter and interference rejection, target resonance and other identification phenomenology, and very low sidelobe imaging technologies. This technology also provides enhanced situation awareness capability by detecting targets in different mediums.

3.1.3.2.2 Affordable and Enhanced Radar Signal Processing. DTO SE.05.01.ANFE. The Affordable and Enhanced Radar Signal Processing effort develops low-cost (75% cost reduction) advanced signal processing techniques and radar architectures by highly leveraging commercial technology in hardware, software and operating systems. This advanced computing capability will improve SAR image formation and motion compensation, moving and stationary target discrimination, clutter rejection, target identification and all-digital radar front ends.

3.1.3.3 Basic Research. The basic research in new wide bandgap semiconductors, such as SiC and Group V nitrides, promise the potential for extremely high power, high efficiency amplifiers which could significantly drive down size, weight, volume and power requirements of radars thereby enabling more powerful, air-based radar systems. Progress in high temperature superconductors offers the potential for ultra-stable oscillators, channelized filters with extremely sharp cutoffs, and 20 bit, high speed A/D converters to enable radars with required dynamic range to handle the high environmental clutter of the littorals. Finally, a recent breakthrough in research offers, for the first time, the capability to perform real-time, true nonlinear filtering for target tracking.