Environmental source tracking

Several matched‐field processing (MFP) techniques have been developed for localizing a fixed acoustic source. Environmental source tracking (EST) is an approach for determining the track of a moving source. In addition to being attractive from a practical point of view, EST can determine source track in situations in which MFP cannot determine source position. The performance of MFP is limited by the number of propagating modes at the array location. EST can overcome this limitation by exploiting source motion and environmental complexity. For example, EST may be possible when the receiver is placed in a region of the ocean that supports only one propagating mode, a situation in which single‐frequency MFP is impossible. MFP requires the use of either an array of receivers or multiple‐frequency data. EST requires only a single frequency and a single receiver. Problems such as array deployment and array tilt, which are important with MFP, are therefore irrelevant with EST.