An improved method for unwrapping phase difference in bathymetry

The phase difference principle is widely used nowadays to sonar systems used for sea floor bathymetry. The main drawback of this method is that the phase difference is measured with the problem of ambiguity. Hence, a given echo record versus time may be affected by several phase jumps. Here we deal with a new processing to remove this ambiguity which base upon multisource fusion. Unlike traditional unwrapping method, the new method does not perform on every sample, but performs on several intervals which are determined by phase difference continuity, filter is used to decrease the noise in interferometric signals, at the same time the information about amplitude and phase are also considered. The performance of this new method is illustrated by data from a 300-kHz multibeam echo sounder.