OPTIMALITY OF THE CELL AVERAGING CFAR DETECTOR

The cell averaging constant false alarm rate detector has been assumed to be optimal for detecting Swerling I targets embedded in exponentia l clutter and noise of unknown power. This is because the detector use s a minimum variance unbiased estimate (which is also a maximum likeli hood estimate) of the unknown clutter-plus-noise power to set the thre shold. In this paper, we prove, using a result concerning least favora ble distributions in composite hypotheses testing, that the cell avera ging detector is indeed optimal in that it is a uniformly most powerfu l detector.