TRUNCATED SEQUENTIAL CFAR DETECTORS USING WEIGHTED SIGN AND WEIGHTED CONDITIONAL SIGN TESTS

In this paper we propose truncated sequential constant false alarm rat e (CFAR) detectors which are approximations of the optimum sequential sign and sequential conditional sign detectors. The particular approxi mations used here allow exact evaluation of the performances. These de tectors form a test statistic by taking the weighted sum of the output s of a hard-limiter in one case and a dead-zone limiter in the other c ase. The test statistic, obtained after every observation, is compared with two constant thresholds. The tests terminate either when one of these thresholds is reached, or when the number of observations exceed s a predetermined truncation point. Design procedures which guarantee a CFAR are presented. Numerical comparisons with some reported detecto rs are given. The proposed truncated CFAR detectors gain improvement o ver their corresponding non-truncated CFAR detectors in reducing the a ver age sample number under signal mismatch, at the expense of a move involved design process. The proposed truncated CFAR detector with con ditional test is uniformly better than a previously reported CFAR dete ctor.