Sea bottom detection technique using multi-subarrays in swath bathymeter system

A bottom detection method used in the multibeam bathymeter sonar is introduced. The method is based on the separate aperture method, which is associated with phase information. As the generalization of the separate aperture method, multi subarrays can be used to estimate DOA of bottom echoes, and the depth is calculated by image transform using phase information. This technique was simulated by computer and tested with experimental data. The results show that this method can improve measurement accuracy of large angles of incidence, efficiently advance depth measurement precision and solve the problem of relative big measurement errors using amplitude based method when angles of incidence is large.