Radar sensors programs directly support JWSTP's areas of Information Superiority, Precision Force, Combat Identification, Joint Theater Missile Defense, Counter Weapons of Mass Destruction, Military Operations in Urban Terrain, and Joint Countermine by offering "near-perfect," real-time knowledge of the enemy on a global basis. Important objectives include heightened ability (20-dB improvement) to detect low-RCS targets using surface-based and airborne wide area surveillance (WAS) sensors; breakthrough capabilities to detect and classify foliage-concealed, time-critical targets as well as underground targets; development of affordable hardware (<$200,000/copy) to provide decisive target acquisition and fire control capabilities for armored vehicles, and an increase in radar instantaneous bandwidth (to 1 GHz and beyond) to achieve improved target classification, identification, and tracking.
Service requirements for radar are moving beyond detection to target classification, which is now driving radar performance to high-resolution, precisely registered n-dimensional measurement capability. Because cost reduction is an important aspect of all new DoD systems, significant use of COTS equipment and novel electronically scanned antenna designs are being pursued. The UHF/L-band array technology is 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 low-frequency ultra wideband (UWB) radar and the concealed target detection (CTD) algorithm programs lead to required capabilities in battlefield surveillance from platforms such as UAVs. The high-frequency (HF) surface wave and UWB technology is planned for transition to improve/upgrade the Navy's surface fleet surveillance and over-the-horizon (OTH) targeting capabilities.
3.1.2.1 Goals and Timeframes. The radar sensor can provide capability for all-weather, long-range detection, location, and recognition capability of significant military targets. However, continued technology development is required to meet the evolving needs of the warfighter. The goals of the radar program are listed in Table VII-2. Meeting these goals depends on advances in ATR (3.4), 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, 3.12, 3.13, 3.14).
3.1.2.2 Major Technical Challenges. The alignment of radar DTOs with the JWSTP is accomplished by defining key challenges. The DTOs are then defined by the specific near-term and long-term goals and milestones associated with each challenge. Three key radar sensor challenges are affordability, enhanced detection and discrimination of low-RCS targets in difficult environments (clutter, noise, and CC&D), and enhanced resolution and quality imaging.
| Fiscal Year | Goal |
|---|---|
| FY97 | Develop/fabricate/test a shipboard HFSWR that can detect low-flying antiship missiles at OTH ranges exceeding 20 nmi. |
| FY00 | 20 dB improvement in clutter cancellation. 10x improvement in resolution. |
| FY03 | Detect targets in foliage, ground, and buildings (90% Pd). |
| FY05 | Counter 1,000-fold reduction in RCS. 75% cost reduction of radars. |
Affordability. This major technical challenge's objective is to improve the capability of radar sensors while significantly improving affordability, especially in an environment of declining quantities of weapon system platform integration opportunities, thus reducing the sensor production base. Specific examples of this challenge include utilization of COTS and MMIC, and development of digital receivers and low-cost electronically scanned arrays (ESAs). By making radars more affordable, the warfighter will reap the benefits of the acquisition of larger numbers of more capable systems previously unavailable to his budget. This will have a pronounced effect on future radar systems, especially UAVs, helicopters, and tanks. The long-term goal for this challenge is a 75% reduction in the production cost of radars.
Enhanced Detection/Discrimination of Low-RCS Targets in Difficult Environments. This major technical challenge's objective is to improve the detection and track of advanced targets in severe clutter and interference (intentional and nonintentional environments). Specific research areas include foliage and ground penetration using low-frequency OTH detection of low-altitude, cruise missiles using HF surface waves; detection of targets in severe clutter from moving platforms using space-time adaptive processing and offboard sources; improved target tracking using advanced algorithms (e.g., knowledge-based techniques, multiple hypothesis testing); and detection of stationary targets using real and synthetic aperture radar (SAR) techniques. Long-term goals are a 20-dB improvement in clutter cancellation, countering a 1,000-fold reduction in radar cross section, and detection of targets in foliage, under ground, and in buildings with a 90% Pd. This capability will deliver to the warfighter superior knowledge of the battlespace in any environment.
Enhanced Resolution and Quality Imaging. This major technical challenge's objective is to improve the capability to produce fine, high-quality, one- and two-dimensional displays of airborne, ground, and sea targets of interest. A major research area in this challenge is the detection of a periscope in high sea clutter. Other research areas include image-while-scan inverse SAR (ISAR) using superresolution techniques and multipath mitigation using very wide bandwidths to develop enhanced, low-angle tracking for fire control solutions. A long-term goal of this challenge is an order-of-magnitude improvement in resolution using more capable signal processors, algorithms, and advanced waveform generation techniques. This capability will provide the warfighter with enhanced detection and recognition of targets of interest.
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 useful to the Department of Transportation, local and federal law enforcement agencies, the medical community, and multiple organizations for humanitarian purposes (e.g., search and rescue, buried mine and tunnel detection).
Overcoming the technical challenges defined in Section 3.1.2.2 requires an investment strategy that will achieve the required long-term goals. To achieve the affordability goal of a 75% reduction in production costs of radar by FY05, utilization of COTS and MMIC technology must be coupled with the development of digital receivers and low-cost ESA antennas. To achieve the enhanced detection and discrimination of low-cost RCS targets in difficult environments, technology efforts must result in a 20-dB improvement in clutter cancellation, countering a 1,000-fold reduction in RCS, and the detection of targets in foliage, under ground, and in buildings with a probability of detection of 90%. Research efforts will focus on low-frequency radars for foliage and ground penetration. Research efforts will apply advanced algorithms to enhance target tracking. Real and SAR technologies will be applied to overcome the challenges of detecting stationary targets in clutter. To solve the difficult problem of detecting targets in severe clutter from moving platforms, space-time adaptive processing techniques will be applied. Significant improvements in image resolution requires technology investment that incorporates more robust signal processors, algorithms, and advanced waveform generation techniques.
3.1.3.1 Technology Demonstrations.
None.
3.1.3.2 Technology Development.
Low-Cost Electronically Scanned Antennas (DTO SE.01.02). Candidate lens and antenna material technologies will be evaluated by the Army, Navy, and Air Force to significantly reduce radar system costs and improve radar system reliability while maintaining overall system performance.
Foliage Penetration Detection Algorithm Demonstration (DTO SE.02.01). Experiments will be conducted using low-frequency SAR sensors to yield statistics to support development of foliage penetration radar system technology and requisite target detection and discrimination algorithms.
Enhanced Moving Target Detection Development (DTO SE.03.01). This technology development will focus on detection of targets in severe clutter from moving platforms using space-time adaptive processing and offboard sources, improved target tracking using advanced algorithms, and detection of stationary targets using real and SAR techniques.
High-Frequency Surface Wave Radar Shipboard Demonstration (DTO SE.04.02). The HFSWR demonstration will provide OTH critical early warning of low-flying missiles (30 seconds for Mach 2+ target) and cue weapon engagement radars.
Automatic Radar Periscope Detection and Discrimination (DTO SE.05.01). This technology development will demonstrate the advanced radar technology necessary for surface ship and airborne radars to automatically detect exposed periscopes in the presence of sea clutter and small targets and debris found in the littoral environment.
3.1.3.3 Basic Research. The basic research in new wide bandgap semiconductors, such as SiC and Group V nitrides, promises the potential for extremely high-power, high-efficiency amplifiers that could significantly reduce 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 ultrastable 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.
