Approximate Invariance of the Inverse of the Covariance Matrix and the Resultant Pre-built STAP Processor

Space-time adaptive processing (STAP) has been proven to be optimum in scenarios where an airborne phased-array radar is used to search for moving targets. The STAP requires the inverse of the covariance matrix (ICM) of undesired signals. The computation of the real-time ICM is impractical at current computer speeds. Proposing two Theorems, this report indicates that the ICM is approximately invariant if radar and platform parameters remain unchanged. A pre-built STAP (PSTAP) processor is then proposed. Both the simulated data from a generic airborne phased array radar model and real data collected by the multi-channel airborne radar measurement (MCARM) system are processed to verify the processor. Results indicate that the performance of the proposed PSTAP processor is the same as that of the real-time STAP processor. RELEASE LIMITATION Approved for public release Published by DSTO Systems Sciences Laboratory PO Box 1500 Edinburgh South Australia 5111 Australia Telephone: (08) 8259 5555 Fax: (08) 8259 6567 © Commonwealth of Australia 2005 AR-013-364 March 2005 APPROVED FOR PUBLIC RELEASE Approximate Invariance of the Inverse of the Covariance Matrix and the Resultant Pre-built STAP Processor (U)