Hardware Design Of Portable 3D Sonar Real-time Imaging System

3D sonar imaging technology can help to detect stationary or moving target’s detailed features underwater and provides multi-angle observation, the technology has broad application prospects in many areas. The current real-time 3D sonar imaging devices complete the sonar scan mostly with plane arrays. This kind of devices’ structure is complex and bulky, they can only be install on the boat or trailer.Normolly, the devices are used to detect broad area with high resolution. This thesis develops a new kind of portable real-time 3D sonar imaging system with line-array technology. The system architecture is significantly simplified and the device is more lightweight. It’s capable of detecting complex underwater environment accurately and flexibly. The system has obvious advantages in the hydrographic survey, coastal dams checking, underwater construction or other applications.The portable real-time 3D sonar imaging system transmits and receives the sonar pulses with different frequencies to detect the targets by two ling-arrays which are perpendicular to each other. The system uses multi-laminated board structure, it is consist of signal processing board, echo-sonar receving board, power board and bottom board. The job of FPGA is controlling the syntronous transimital and receive of the sonar signal. The echo-sonar receving board optimizes beamforming algorithm, it uses distributed beamforming mode to substantially increase sonar signal processing speed. The signal processing board uses digital media processor with low power comsuming to complete real-time 3D imaging and transmit the image data to the PC with gigabit ethernet.Experiment results show that the system is able to detect and display the underwater envirenment clearly by the range of 40m. The system’s distance resolution is 3cm, and the angle resolution is 1.2°. The indicators meet the design requirements, and the system has high practical value in engineering application.