Detection analysis of CA family of adaptive radar schemes processing M-correlated sweeps in homogeneous and multiple-target environments

摘要

Most radar systems need some form of Doppler processing to filter out clutter and thereby reveal faster targets. The using of a moving target indicator (MTI) as a part of detection processing attenuates the input signal power at frequencies where the clutter return is dominant. However, the presence of MTI complicates the analysis of the detection system performance since its output sequence is correlated even though the input sequence may be uncorrelated. This paper is devoted to the detection performance evaluation of the mean-level CFAR detectors processing M-correlated sweeps in the presence of interfering targets. The consecutive pulses are assumed to be fluctuating according to the Swerling I model. Exact expressions are derived for the detection probability of the conventional mean-level detector (MLD), the maximum (MX)-MLD and the minimum (MN)-MLD under Rayleigh fluctuating target model. Performance for independent sweeps can be easily obtained by setting the sweep-to-sweep correlation coefficient equal to zero. Results are obtained for both homogeneous and nonhomogeneous background environments. It is shown that for fixed M, the relative improvement over the single sweep case increases as the correlation between sweeps decreases. When the correlation coefficient approaches unity. no gain is obtained for M > 1 over the monopulse detection performance. For the same parameter values, the MN-MLD gives the best performance in the presence of interfering target returns among the reference noise samples.