Short time correlator delay estimation in the presence of interfering sources

Time delay estimation is a complicated problem if the delay is time-varying as a result of contact motion. This delay estimation is further complicated if multipath and interfering sources are present. This paper describes an algorithm based on the superposition of short time cross-correlations of the received signals at two sonobuoys. The advantage of this algorithm is that it can be used to significantly reduce the interference due to other sources and multipath. A parallel search based implementation is briefly described which reduces the search time and is conducive to VLSI implementation. A linear time-varying delay is assumed to simplify the presentation, though the algorithm can be implemented for a non-linear time-varying delay by increasing the number of search variables