A novel sonar development platform: dual frequency sonar beam shaping for angular localization

Abstract

This thesis presents a complete airborne ultrasound system inspired by both underlying physics and biological sonar. First, a completely new hardware platform is designed and developed. This design supports an extendible and flexible sensor topology. Next, the associated firmware is designed and implemented. This software provides all the lower-level communication among the distributed sensors and the host processor while employing a new bus arbitration technique. An accompanying PC development environment is created. The result is an unique integrated system that holds the promise of providing research and development platform for future sonar work without requiring changes in the hardware and software infrastructure. This is demonstrated in the problem of finding angular position. As is well known, sonar sensors are capable of finding radial position of a target object quite precisely, however they have very low angular resolution. Previous work has proposed methods that are based on multiple sensors and hence are relatively complex. This thesis proposes a novel approach based on only a single transducer. This approach is based on dual frequency beam shaping. Experiments serve to demonstrate that even with minimal hardware, and hence processing power and cost, angular accuracies of order 0.5 degrees are easily achievable.