Universal High Resolution Imaging Sonar Simulation Toolkit

Abstract

We have been working towards the development of meaningful computer models for building imaging sonar systems and the external environment in which they operate1–5. This paper presents a Universal High Resolution Imaging Sonar Simulation Toolkit which is a software development tool for building imaging sonar simulators operating in a variety of underwater scenarios. They can be used in several unprecedented simulation applications like designing and testing the performance of sectorscan and sidescan sonar systems, tracking of underwater vehicles, underwater vehicle navigation, object search and location on the sea bed, obstacle avoidance etc. The toolkit could also be used to simulate an animated sequence of images during a particular “run” along a user selectable path/route in a 3D bounded ocean volume. The Toolkit is kept flexible and modular and to enable a user to build a wide variety of applications simply and quickly, the programs have been interfaced to X11 Window System. The user interface has been written using low level Xlib routines so that it can run on many types of workstations without changes. The application program has two major modules. In the 3D ocean scenario module, the user can create a number of moving and stationary objects and position them anywhere in the ocean volume with different types of sea bottom (flat, sloping and a few complex 3d surfaces). Once the 3D scene is generated, the module computes the visible coordinates using a new algorithm for the removal of hidden/occluded surfaces. The second module is the acoustic imaging sonar module which can model sectorscan/sidescan sonar, acoustic shadows, terrain shadows in case of non-flat surface, specular reflection, receiver array geometry, number of receiver elements, receiver beam pattern, overlapping beams, absorption and transmission loss, bottom reverberation, ambient noise, target strength etc. The toolkit provides 3d acoustic sectorscan sonar images (bearing, elevation and range) and 2d acoustic sidescan images (bearing and range).