Design of the SPRT for radar target detection

Sequential techniques for signal detection are becoming increasingly important in radar applications. In the paper the authors focus their attention on the sequential probability ratio test (SPRT), used for radar target detection. This test was proposed and analysed for the first time by Wald, 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. In the work the authors present the exact analysis of the SPRT in the following cases: (i) coherent detection, (ii) incoherent detection with nonfluctuating target and (iii) incoherent detection with a Swerling-II-type fluctuating target. The results are summarised in a set of graphs which are useful for both design and analysis purposes.