Parametric Filters for Non-Stationary Interference Mitigation in Airborne Radars

摘要

Multichannel parametric filters are currently being studied as a means of reducing the dimension of Space-Time Adaptive Processing (STAP) algorithms for interference rejection in airborne pulsed-Doppler radar systems. These filters are attractive to use due to the low computational cost associated with their implementation as well as their near-optimal performance with a small amount of training data for a stationary environment. However, such filters do not perform well in certain types of non-stationary environments. This paper presents two modifications to the Space-Time AutoRegressive (STAR) filter that the authors previously proposed. The first modification is based on the Extended Sample Matrix Inversion (ESMI) technique and is used in the presence of range varying clutter that arises from the use of non-linear antenna arrays or bistatic radar systems. The second modification to the STAR filter is for use in the presence of hot clutter and is a three-dimensional STAP algorithm. Using a realistic simulated data set for circular array STAP, the authors show that the modifications to the STAR filter improve its performance when in the presence of non-stationary interference. (6 figures, 8 refs.).