An improved motion error estimation algorithm for SAS using a displaced phase center antenna

Motion error estimation is the key technique for synthetic aperture sonar (SAS) imaging. An improved motion error estimation algorithm for SAS using a displaced phase center antenna (DPCA) is proposed in this paper. With this method, the path length difference between the actual path length and the approximated path length using equivalent phase center is corrected for the signal of each DPCA element firstly, then motion error is estimated based on time delay and residual phase error estimations. A versatile method for phase error estimation is described. Through these ways the motion error scope that can be estimated is extended and the accuracy of motion error estimation is enhanced. Some simulation results are given in the end of this paper.