Performance analysis of space–time-adaptive monopulse

Abstract

The two-dimensional monopulse estimation scheme is extended to space- and time-adaptive processing (STAP) for arbitrary sum and difference beams and arbitrary subarrays in space and time. This includes the case of time samples at the pulse repetition frequency (PRF, slow time STAP) as well as time samples at Nyquist frequency according to the receiving bandwidth (typically samples from range cell to range cell, fast time STAP), or both. We then show how the distribution of the monopulse estimates, which was developed in a previous paper, can be extended to this generalised monopulse. The meaning of the distributional assumptions for the signal (fixed target, Rayleigh target) is explained for the different types of space–time data. The application of these distributions as a performance measure is then demonstrated by comparison with the Cramér–Rao bound for different scenarios, different types of beamforming (narrowband or broadband beam forming), and different types of subarray configurations, like the generalised sidelobe canceller, which can be interpreted as a special subarray configuration.