Analysis & design of multiple-input multiple-output synthetic aperture sonar systems.

摘要

A synthetic aperture sonar (SAS) system is a sophisticated invention which forms high resolution images of the seafloor. The main issue of a SAS system is its low platform speed. This is due to the need to accurately estimate the position of the sonar transducers in real-time. Using a single transmitter, multiple receiver (SIMO) system reduces this problem. In an attempt to further augment the traveling speed, we propose a SAS system with multiple transmitting elements placed along the cross-range direction, and colocated with some of the receiving elements. The transmitters emit a set of orthogonal (or nearly orthogonal) waveforms. We analyze the pros and the cons of this multiple input multiple output (MIMO) design with a simulator that is built during this project, and look into ways to resolve some of the complications. Specifically, we show that the MIMO configuration does allow for faster platform speed. Further, the MIMO configuration can improve the near field cross-range resolution. Finally, we show that these gains are possible if any cross-talk between the transmitted waveforms is suppressed.