Development of an in-air circular synthetic aperture sonar system as an educational tool

Abstract

Synthetic aperture sonar (SAS) is an underwater acoustic imaging technique that is used to generate high quality imagery through the coherent combination of signals measured on a moving platform. The practical challenges of underwater experimentation and the lack of publicly available data sets make it difficult to teach SAS processing to students using experimental data. These challenges are compounded by the complicated signal processing that is required to compensate for the unwanted platform motion that is common in field data. This paper details the development of an in-air circular SAS system using commonly available laboratory equipment. By operating in air and using a circular geometry many of the challenges that students would otherwise encounter in SAS processing are either well controlled or completely eliminated. Imagery collected on the system is shown to demonstrate how meaningful data can be generated using a simple set of equipment. A number of applications of the system as a tool to teach array signal processing, pulse compression, and imaging concepts are also discussed.