CFAR loss and gain in K-distributed sea-clutter and thermal noise

Setting the detection threshold in a radar operating in a maritime environment is critically dependent upon the characteristics of the sea clutter. Analysis is presented in this paper of the performance of the cell-averaging CFAR in K-distributed sea clutter. It is demonstrated that in spatially uncorrelated, spiky clutter the CFAR loss is very high, but may be reduced in some circumstances by increasing the radar system noise level. It has previously been reported [5] that in spatially correlated clutter the CFAR loss may be reduced by optimising the cell averager length, which is some cases leads to a ‘CFAR gain’ rather than a loss. Here, it is shown how added thermal noise affects this performance.