Design of the SPRT for radar target detection

Sequential techniques for signal detection are becoming increasingly important in radar applications. In this paper attention is focused on the sequential probability ratio test (SPRT), used for radar target detection. This test was proposed and analyzed for the first time by Wald (1947), who developed a method to approximately determine the performance of the SPRT. Unfortunately, this method is not valid in radar applications, so an exact analysis of the SPRT is required. An exact analysis of the SPRT is presented for the following cases: coherent detection, incoherent detection with nonfluctuating target, and incoherent detection with a Swerling-II-type fluctuating target. The results are summarized in a set of graphs which are useful for both design and analysis purposes.