Low Frequency SAS: Influence of multipaths on Spatial Coherence

Multipath is an issue for the performance of synthetic aperture sonars. In HF-SAS (high frequency SAS) images, multipaths effects manifest in hiding targets, loss image contrast and degradation interferometry bathymetric estimates spatial coherence due to a decrease SNR. this study, behaviour LF-SAS (low equipped with full 2D receiving array analysed. This Rx enables observation coherence. On vertical axis, existence multipath reflects on emergence lobes figure Intuitively, can be understood considering that direct path seen from reception as two sources act dipole antenna. study aims at evaluating these establishing link between lobes). The builds upon data acquired by HRLFSAS designed NATO CMRE. effect highlighted thanks analytical modelisation comparison observed one predicted application Van Cittert Zernike theorem distribution energy estimated beamforming.