Adaptive digital array processing in airborne radars can provide a major improvement in detection and tracking capability by adaptively suppressing clutter and jamming. The effectiveness of this space-time adaptive processing has been demonstrated by detailed simulation at ASI. Recently, array radar flight test data was used to verify the performance of adaptive radar. During the Phase I effort, the simulation of space-time adaptive radar was extended to include angle tracking and the cancellation of terrain scattered interference (TSI). The major objective of the Phase II effort is the further development and detailed simulation of adaptive algorithms for suppressing TSI. The simulation programs will be structured to accept recorded terrain scatter data and compare different cancellation algorithms using either simulated inputs or recorded data. A second objective of the Phase II effort is the development and simulation of algorithms for angle measurement in adaptive array radars. When the antenna patterns are adapted in response to clutter and jamming, the pattern distortions add errors to conventional angle trackers, such as monopulse. A maximum likelihood angle estimator for these systems was described and simulated during Phase 1. This effort will be extended to include terrain scattered interference. Anticipated Benefits/Potential Applications - The angle tracking and TSI suppression techniques will provide an important capability for missile seekers and Al radars. Both have potential applications in non-military radars operating in clutter and electromagnetic interference.
