Some general considerations for synthetic aperture sonar design

This paper is devoted to synthetic aperture sonar for sea bottom imaging. The reader is assumed to be familiar with this topic on which a large literature is available. The paper is composed of four parts. Part 1 aims at determining the domain of interest of the synthetic aperture mode with respect to the real aperture mode in terms of along-track resolution, range, array length and speed. In part 2 the effect of a speed overpass is illustrated on sonar images from a computer simulation. In part 3 accuracy requirements are assessed for the motion sensing system. In part 4 autofocusing methods allowing to make the above requirements less stringent are briefly reviewed.