A method for estimating along-track velocity of synthetic aperture sonar

Along-track velocity is critical for synthetic aperture sonar (SAS) imaging, as well as for the navigation of carrier. SAS systems typically measure velocity through a Doppler Velocity Log (DVL), but it is not always available. Based on these, this paper describes a method for estimating the along-track velocity using displaced phase center (DPC) approximation. The main idea of the proposed method is to obtain the displacement of SAS between two adjacent pings using the spatiotemporal cross-correlation coefficient matrix, and then find the along-track velocity by a calculating formula. Simulations and results of real data from lake experiments show that the estimated velocity is quite accurate, and the estimated velocity can be used for carrier navigation and image reconstruction.