A low-altitude Hypersonic Cruise Missile (HCM), launched against a Navy ship, presents a unique challenge for ship self-defense systems. Ship-based radar systems may detect the HCM with as little as 10 seconds before impact. The detection and tracking of inbound HCMs is extremely challenging due to the short timeline, the small radar cross-section (RCS) of HCMs, and the additional effects that the plasma envelope surrounding the HCM has on the radar signal. An airborne platform with a capable radar system could, potentially, detect the HCM between 50 and 60 seconds before impact, significantly increasing the time available to detect, track, lock onto, and then launch interceptors to counter the HCM. Suitable aircraft for hosting this early-warning radar include high-altitude long-endurance (HALE) and medium-altitude long-endurance (MALE) unmanned aircraft systems (UAS). ARTEMIS, Inc. proposes, together with Johns Hopkins University Applied Physics Laboratory (JHUAPL), to develop, design, and demonstrate a radar mode with associated signal processing suitable for use on modern Navy airborne radar systems. At ARTEMIS, we will leverage our technology and experience developed as part of our next-generation SlimSDR radar system development (from an Army Phase II SBIR), and our experience with stratospheric radar operation (a dozen stratospheric balloon flights) and UAS integration, to meet the requirements of this SBIR topic. This includes system modeling and simulation, multi-mode performance calculations, real-time Synthetic Aperture Radar (SAR) and Moving-Target-Indicator (MTI) processing, and waveform design/analysis. JHUAPL will leverage its considerable experience in operational SAR, algorithm development, systems engineering, and testing to advance this effort. This experience includes the design, development, launch, and operation of mini-SAR and mini-RF, which are synthetic aperture radar missions to the Moon. JHUAPL also has significant experience detecting and classifying moving objects in synthetic aperture radar. This experience has been demonstrated for a variety of target types, including maritime targets. This combination of hardware experience, operational experience, and algorithm design via SAR data exploitation provides JHUAPL a unique perspective to assist in the advancement the proposed system. ARTEMIS is developing a radar technology called High-PRF, Orthogonal Waveform, Intra-Pulse, Long-Range Radar (HOWILRR), which allows for detection and tracking, with unambiguous range and velocity, of fast-moving targets at long ranges. This technology was invented for defense against HCMs. In Phase I, HOWILRR, and other potential techniques and technologies, will be developed and evaluated using high-fidelity target and clutter modeling and simulation software. The most promising concepts will be further developed and, in Phase II, demonstrated in a prototype.
