Performance analysis of RADARSAT-2 multi-channel MODEX modes

It has been recognized that a two-aperture approach to ground moving target indication is sub-optimum and that target parameter estimation is often compromised by clutter interference or poor signal-to-clutter ratios. This paper investigates the ground moving target indication (GMTI) performance of several virtual channel concepts proposed for the RADARSAT-2 moving object detection experiment (MODEX). These are capable of increasing the spatial diversity of RADARSAT-2 by exploiting its very flexible antenna programming capabilities and allowing the two-channel SAR system to operate like a three or four channel radar. A high fidelity space-based radar moving target indication simulator (SBRMTISIM) is used to generate virtual channel raw GMTI data for analysis. Moving targets are detected using a combination of the factored space-time adaptive processing (factored STAP) and the cell-averaging constant false alarm rate (CA-CFAR) detector. The detection performance of virtual multi-channel MODEX modes are analyzed and compared with those of the standard two-channel MODEX mode and a true three or four channel space-based radar system.