Abstract :
Space based radar (SBR) surveillance concepts have been investigated for decades and have once again made an appearance as a viable means of performing the ground moving target indication (GMTI) mission. From the signal processing perspective, a number of unique technical challenges must be addressed. These include a larger Doppler clutter spread, which will cause moving targets to be more likely in the endoclutter region, larger target densities, and nonhomogeneity and/or nonstationarity of the collected data. These and other phenomenology impact the ability of algorithms implemented by the system to perform target detection and parameter estimation. Various adaptations of space-time adaptive processing (STAP) have been put forward as the primary, if not only, solution to detect and locate ground moving targets (GMTI) in complex clutter environments from airborne and/or space based radar platforms. Most, if not all, of the proposed variations can be optimized to work in specific environments but suffer degradation when called upon to perform in a different setting. The reason for this appears to be inherent to the process itself. In order to overcome the difficulties described above, an alternative approach to the current STAP paradigm has been developed and studied for target detection and location in multichannel radar systems. The new technique is based on an adaptation of a previously developed technique, used in passive arrays for angle of arrival (AOA) estimation, in conjunction with a knowledge based array calibration technique. When combined together, these two algorithms provide a powerful new tool for the detection and location of moving targets in complex clutter environments
Keywords :
array signal processing; direction-of-arrival estimation; radar clutter; radar detection; space-time adaptive processing; spaceborne radar; Doppler clutter spread; GMTI; SBR surveillance; STAP; angle of arrival estimation; complex clutter environments; ground moving target indication; knowledge based array calibration; multichannel radar detection; parameter estimation; passive arrays; phenomenology impact; radar location; space based radar; space-time adaptive processing; target detection; Adaptive arrays; Clutter; Degradation; Object detection; Parameter estimation; Radar detection; Radar signal processing; Signal processing algorithms; Spaceborne radar; Surveillance;