Baseline decorrelation in acoustic tools for surveying the seafloor

Abstract

Baseline decorrelation, also known as geometric decorrelation, is a limiting factor in the performance of interferometers that feature large baselines. This phenomenon can be thus a bottle-neck in the development of new surveying tools, e.g. forward-looking synthetic interferometers or imaging systems based on squint synthetic aperture. The mechanism responsible for geometric decorrelation is put in evidence by using a simple model of surface scattering, with an idealized pair of transmitter-receiver running the 'stop and hop' scenario within a 2D geometry. Geometric decorrelation can be countered in several cases of practical interest. The choice of the transmitted signals and the relevant signal processing at receive that aim at reducing or even cancelling this effect are developed. Numerical examples are given in realistic configurations. © 2013 Acoustical Society of America.