Experimental verification of high resolution GMTI radar

Ground moving target indication (GMTI) describes generic radar modes that allow detection of ground moving targets against a background of clutter. These systems usually use a low range resolution to mitigate the effects of range walk during the processing interval. In addition to simple detection of moving targets, it is often desired to provide some level of target classification (e.g. tracked or wheeled vehicles) and in systems with low range resolution Doppler signatures of the targets may be used to classify them. Additional information contributing to target classification may be achieved by using high range resolutions [HRR classifiers]. In a high resolution GMTI (HR-GMTI) radar both the range profile and Doppler could be used to classify targets. In addition, high resolution may provide enhanced sub-clutter visibility. This paper reports experimental results from trials by Thales of two experimental radar systems. It illustrates the problem of range walk in HR-GMTI and the performance of method to correct this. In addition, a two channel space-time filtering technique is described to suppress mainlobe stationary clutter. A clutter suppression of ∼ 20 dB is reported.