A 3D forward-look sonar simulation model

Abstract

A modeling tool for 3-D Forward-Look Sonar (3-D-FLS) or equivalent has been developed. The model replicates the entire process of a 3-D Forward-Look sonar generating a 3-D image of a target. The 3-D-FLS operates at a central frequency of 225 kHz and has a range of 100 m. The transmitted signal is a frequency-modulated chirp with 30 kHz of bandwidth. The source is a line array and the projector is a 64-element line array. Ray theory is used to calculate the trajectory of the rays. The model takes sound velocity profiles into account. The reverberation levels due to the sea bottom and sea surface are calculated using Kuos model. Targets of various shapes and sizes are modeled as a collection of reflecting data points. The target strengths of each point on a specific target are assumed equal. The final product is a modeling tool which can be used to define the sonar hardware and processing software necessary to achieve various operational needs. Simulated results are validated using 3-D-FLS data collected during several at-sea experiments.