Synthetic aperture sonar array gain measured at sea

A synthetic aperture sonar (SAS) typically consists of a directional transmitter and two vertically displaced receiving arrays, placed in a rigid frame. Many receivers permit an adequate area coverage rate and partly solve motion estimation issues. SAS motion estimation is crucial for image quality and is partly accomplished by using the ping-to-ping correlation obtained from overlapping elements. SAS gain depends on this ping-to-ping correlation. In this paper, theoretical impact of motion estimation accuracy and geometry on the SAS gain are formulated. Also, array gain is investigated using real data collected at sea with NURC's SAS.