Prospectives in STAP Research

Space-time adaptive processing (STAP) has received considerable attention by the radar community during the past decade. There are several applications such as broadband interference rejection, terrain scattered jamming and clutter cancellation in pulse-Doppler radars carried by a moving platform (aircraft, satellite). The latter applications require a coherent multichannel phased array antenna. Combinations of the three mentioned applications are possible. In this lecture, we focus on clutter cancellation for moving radar. After a short introduction into the principles of STAP, the following research topics of current interest are addressed:

1. Range dependence of clutter Doppler.

For all array configurations other than sidelooking the clutter Doppler is range dependent. This may require range-dependent processing. Problems with adaptation may be encountered because the availble amount of training data might not be sufficient.

2. Order reduced architectures for real-time processing.

Reduction of the signal subspace may lead to dramatic saving in computational load as well as in reduced amount of required training data. Real-time on-board processing appears to be possible.

3. Bistatic radar configurations have certain operational advantages for military applications. In general the clutter Doppler becomes range dependent even for sidelooking array geometry.

4. Estimation of azimuth and Doppler in a heavy clutter environment using a STAP radar is an essential input for subsequent tracking algorithms. The estimation performance of a class of subspace processors can be analysed by calculating the Cramér-Rao bound.