A Method of SAS with Sparse Aperture Based on Compressive Sensing

High resolution synthetic aperture sonar (SAS) is limited by some factors such as size of the sonar carrier, carrier speed, underwater sound velocity and sound propagation characteristics, so obviously the mapping efficiency of SAS is less than that of synthetic aperture radar (SAR). In order to break through the problem of low mapping efficiency, this paper proposes a method of sampling sparse in azimuth direction to obtain higher operation efficiency. The signal is transformed into SAS imaging by stripe along the range direction to solve the effect of range migration caused by the motion of carrier. And the scattering coefficient is reconstructed by one of the compressed sensing (CS) method called best orthogonal matching pursuit (OMP) algorithm, in order to obtain the final SAS imaging. The simulation and experimental data imaging results show that the method can still realize the imaging without ambiguity under the condition of the enormous down sampling along the azimuth direction. It solves the problem of the grating lobe effect caused by sparse sampling, improves the mapping efficiency greatly and has strong effectiveness and practicability.