Exact performance of STAP algorithms with mismatched steering and clutter statistics

Adaptive algorithms for receivers employing antenna arrays have recently re ceived significant attention for radar systems applications. In the majorit y of these algorithms, the covariance matrix for the clutter-plus-noise is characterized by using samples taken from range cells surrounding the test cell, If the underlying covariance matrix of the test cell is different fro m the average covariance matrix of the surrounding range cells, significant performance degradation may result. Exact expressions for performance are derived for such cases, when any of a set of popular space-time adaptive pr ocessing (STAP) algorithms are used, Numerical evaluation of these expressi ons illustrates how variations in the parameters of these equations affect probability of detection and probability of false alarm, The equations are utilized to determine an upper bound on the performance of this class of ST AP algorithms.