Improvement of target resolution in azimuth by LMMSE technique

Azimuth target separation is of crucial importance in many applications of radar. The azimuth resolution is determined by the antenna beamwidth. However, in practice, standard signal processing techniques require the distance between targets to be more than one resolution cell. This can prove inadequate for several relevant applications. In this paper the problem of improving the azimuth resolution for rotating surveillance radar is addressed. A data model for the case is described and a novel application of the linear minimum mean square error (LMMSE) processing technique is evaluated. The antenna pattern used is obtained from real measurements and the received signal is synthesized to produce target profiles with spacing smaller and larger than the resolution cell. Results show the capabilities of this technique of separating targets in azimuth spaced closer or further than one azimuth resolution cell. The processing scheme shows a large improvement in the resolution capability with respect to standard techniques.