Submarine Objects Echo Simulation And Image Generation

Underwater acoustic imaging is widely utilized in underwater investigation, especially in seabed mapping, target detection and classification. It converts the raw signals into two-dimensional (2-D) or three-dimensional (3-D) images for direct observation, it also allows for large-scale exploration and turbid water operation. The study of underwater acoustic imaging has great significance for design and realization of imaging sonar.The purpose of this thesis is to study the simulation of acoustic imaging of seabed objects. So the method of simulating the target echo is firstly introduced to acquire echo, then the concept and characters of acoustic imaging is presented, following the basic imaging forms with emphasis on beam forming and synthetic aperture, where after the 2-D and 3-D imaging is carried out. Finally the acoustic imaging simulation of sphere target on rough seafloor using simple models is made.The main contributions are as follows:1. The echo models: point-scatterer collection model, highlight model and form function model are studied. Based on sphere and cylinder, the simulation methods of echo are given as well as the simulation results of rigid and elastic targets.2. The basic acoustic imaging methods: acoustic lens, beam forming and acoustic holography are presented focusing on beam forming, following the simulation of 2-D and 3-D target imaging using time-delay and phase-shift beam forming, the parameter effects of 3-D imaging are also analyzed.3. The simulation of point and point array imaging using synthetic aperture technique is carried out, as well as the simulation of the sphere imaging on rough seafloor using point-scatterer collection model and beam forming method.