Class of optimum MTI filters for clutter rejection

Abstract

The problem of optimum design of an m.t.i. system for clutter rejection is considered in this paper. The procedure involves minimisation of the output clutter power subject to the constraint that the average output-signal power over the expected target Doppler range is to be kept constant. Another constraint in the minimisation problem is incorporated, according to which the transfer function of the system has a null at the dominant clutter Doppler frequency fm, which may often be zero. In this way, the distributed component of clutter is minimised at the filter output while the clutter component at a fixed mean relative velocity is completedly suppressed. With the two constraints specified above, the problem is mathematically formulated as a modified eigenvalue problem. Comprehensive results for the performance of the resulting filters are presented.