Optimization of STAP for Bistatic Space-Based Radar Systems

A bistatic space-based radar (SBR) system with a MEO or GEO transmitter and a LEO (or airborne) receiver offers three advantages over a LEO monostatic radar: (1) fewer satellites are required at the higher MEO/GEO altitudes, (2) passive receivers are difficult to detect and jam, and (3) receivers are located nearer to the targets, decreasing transmit power-aperture requirements, and improving target detectability. Innovative STAP techniques are required to address two fundamental bistatic SBR challenges: (1) SBRs have large clutter footprints and the transmitter velocities induce large clutter Doppler spreads, making target detection difficult, especially when jammers are present and (2) the clutter Doppler-angle trajectory is highly nonlinear and range-dependent in bistatic geometries. Standard STAP approaches fail under these conditions, because covariance estimation and adaptive degrees of freedom (DOFs) are not tailored to the interference environment. ALPHATECH proposes a systematic study for developing and evaluating optimal approaches that addresses these challenges. This Phase-I effort will focus on: (1) system architecture to optimize SINR, MDV, clutter cancellation, and jammer mitigation, (2) adaptive DOFs tailoring, (3) preprocessing and knowledge-aided training, and (4) simulation tools to evaluate and compare the techniques and architectures we develop. BENEFIT: The technology developed under this program will be directly applicable to military and civilian space-based radar systems. In addition, this technology can also be applied to bistatic radar systems employing transmitters of opportunity, airborne surveillance systems, anti-drug surveillance systems, and communication systems.