Method of phase unwrapping-free DEM reconstruction of InSAS

In this paper a kind of phase unwrapping-free digital elevation model(DEM) reconstruction method of interferometric synthetic aperture sonar(InSAS) is described. Firstly, a new method of coarse DEM generation is proposed. In the method, a pair of images are divided into small blocks and resampled to a set of reference planes. The height of each block pair is estimated by measuring the maximum coherence of the corresponding pair resampled to different reference planes. The entire heights of the blocks are interpolated to obtain the coarse DEM. After that, the resulting coarse DEM is used to flatten interferogram. The residual interferogram generally is unwrapped. Therefore phase unwrapping can be avoided. Simulation result is presented. The resulting DEM indicates that the proposed method has good potential for topographic mapping of the seafloor surface.