Clutter map CFAR detector based on maximal resolution cell

Abstract

In order to improve the detection performance of clutter map constant false alarm rate (CFAR) detectors in multiple persisting targets situation, a clutter map CFAR (CM-CFAR) detector based on the maximal resolution cell (CM/MRC-CFAR) is proposed in this paper. In the CM/MRC-CFAR detector, at each scan, a comparison threshold is computed by multiplying the amplitude of the maximal resolution cell (MRC) in the map cell by a scaling factor. Then, the number of the left resolution cells, whose amplitudes are smaller than the comparison threshold, is counted and compared with a threshold integer. Based on the comparison result, proper resolution cells are selected to update the detection threshold. The detection probability of CM/MRC-CFAR in both homogeneous and multiple persisting targets situations is derived in a closed-form expression. The detection performance of CM/MRC-CFAR is evaluated in various environments and compared with other CM-CFAR detectors. CM/MRC-CFAR exhibits a very low CFAR loss in a homogeneous environment and achieves a robust detection performance in multiple persisting targets situations. Since no ranking is required except searching for the MRC, the computation load of CM/MRC-CFAR is low, and it is easy to implement the detector in radar systems in practice.