Side scan sonar and interferometric noise

This paper concerns the description of different noise sources encountered as well as the impact of each of these sources through the sonar interferometric data acquisition. In fact, these noise sources can generally be classed into two categories: a. environmental noise category (variable celerity, parasite echoes, sonar motion, etc,), and b. interferometric process related noise (decorrelation baseline, decorrelation of wave train, propagation). In this study, each noise source (considered separately) is first modeled in terms of signal to noise ratio (SNR) as a function of range. This modeling is conducted analytically as well as using computer simulations. The obtained information is, then, converted in order to obtain an altitude error precision scheme. Obtained results clearly show that these different noise sources have not the same altitude error impact. In fact, the decorrelation of wave-train and the parasite echoes are shown to be the most significant. Finally, an error data fusion process is studied in order to evaluate the altitude precision degradation through the integration of several noise phenomena. The main conclusion of this paper concerns the theoretical interest of the conducted approach in terms of the obtained results as well as in order to reduce the impact of these noise sources through the physical and the analytical comprehension of the data acquisition process