Performance of distributed CFAR tests in nonhomogeneous background

We evaluate the performance of several distributed CFAR tests operating in nonhomogeneous background conditions. The analysis considers the detection of Rayleigh target in Rayleigh clutter with the possibility of differing clutter power levels in the test cells of distributed radars. The tests considered include the previously defined maximum order statistic detector (MOS), belonging to a class of signal-plus-order statistic (S+OS) detectors, a new normalized test statistic (NTS), also belonging to the S+OS class, and the OR and the AND fusion rules. Numerical results studied for a two-radar system show how the false alarm rate of the MOS test changes with differences in the clutter power levels of the test cells. The results also indicate that, with differing test cells´ power levels, the OR fusion rule can be quite competitive to more complex tests, viz. NTS and MOS