Continuous track-before-detect method for rotating radars.

Mechanically steered scanning radars receive measurements in different azimuths sequentially rather than simultaneously for target detection and tracking. However, in conventional track-before-detect (TBD) methods, the requirement of waiting for all measurements of a whole scan, referring to a certain azimuth, leads to significant processing delays and boundary effect, which appears as that targets around the boundary may be scanned 0 or 2 times in a scan. This may also cause degraded detection and estimation performances. To solve these problems, a continuous TBD method is proposed for target detection and tracking in rotating radars. A space–time joint retrodiction method is presented to produce precise revisit intervals and retrodicted positions, which contribute to immediate and accurate energy integration. Once measurements in an azimuth cell are received, each range cell in this azimuth is retrodicted according to the space–time joint retrodiction method with an assumed velocity. Then, a number S of pseudo-spectra are constructed around the cell and its retrodicted positions in the past S − 1 scans. Samples of each pseudo-spectrum are added onto corresponding cells for energy accumulation. After that, some cells in the past (S − 1) th scan and their guard and reference cells complete energy integration, and thus are detected immediately. Continuous integration and detection are realized without waiting for measurements at the boundary of a scan. This eliminates the boundary effect and minimizes the processing latency. Experimental results corroborate the validity of the continuous TBD method. • Problems of processing delay and boundary effect in rotating radars are considered. • A space–time joint retrodiction method is proposed. • A continuous track-before-detect method based on the pseudo-spectrum is proposed. • The processing delay is minimized, and the boundary effect is eliminated. • Continuous integration and detection are realized. [ABSTRACT FROM AUTHOR]