Clutter rejection using range-recursive space-time adaptive processing (STAP) algorithms in non sidelooking configuration

In this paper, we address the issue of ground clutter rejection for the detection of slowly moving targets in a non sidelooking (NSL) array configuration airborne radar. The classical space-time adaptive processing (STAP) such as the SMI or the eigencanceller-based methods are computationally costly and require the estimation of the clutter covariance matrix from secondary data. However in monostatic STAP airborne radar, the main consequence of the inclination of the array is the range dependency of the clutter covariance matrix. Several compensation methods exist but they are computationally complex or require the knowledge of the radar parameters. We here investigate the use of range recursive subspace-based algorithms of linear complexity inspired by existing time recursive array processing and we show that they are able to track the range dependency (non stationarity) of the data.