Repeat-track SAS interferometry: feasibility study

Repeat track interferometry is a commonly used technology in radar. It permits to obtain topography and elevation variation of ground. This technology is not used with sonar system, even though this configuration could provide interesting applications for underwater environment knowledge. This paper presents a study on repeat-track interferometry feasibility with sonar system, and especially for synthetic aperture sonar (SAS). We shortly expose the SAS and interferometry principle in the first part. Then we present the multi-track interferometry and discuss on limitation. In a third part, experimental results based on data acquired with the experimental low frequency SAS (LFSAS) of GESMA (France), are detailed and we expose methods to circumvent problems induced by repeat-track interferometry. Finally we discuss on future strategies to improve the encouraging results we obtained.