Hardware Design Of The Acquisition And Transmission System For Towed Imaging Sonar

The imaging sonar technology is developed to detect the details of underwater topography, underwater geomorphology, the obstacles and other equipments underwater. It possesses extensive civil applications in ocean research. The imaging sonar receives different frequency sonic data, and then intergrats the data into two-dimentional or three dimentional images. Currently, the main design difficulties of the imaging sonar are how to improve the imaging resolution, the transfer rate of sonic data and the numbers of the sonic sampling channel. The acquisition and transmission system for the towed imaging sonar developed in this thesis would use a multi-channel sampling method. It can be used to survey complex underwater environment and to detect the position and appearance of the obstacles underwater. It has obvious advantages in sampling frequency and the transfer rate of sonic data.The system uses a TI TMS320DM8127 DSP as the core chip for sonic data processing which extendes 8-Gb RAM totally with its internel integrated GPMCs. Using the internal integrated GMAC transmits the data to the Control Center with Gigabit Ethernet and the Control Center System. The system uses a Xilinx Spartan-6 FPGA for multi-channel sonic data sampling and storage. The TMS320DM8127 DSP receives sonic data from the FPGA through a PCI-Express interface, which enhances the overall data transfer speed.Through a system testing, the multi-channel phase consistency is less than 1 degree and the multi-channel amplitude consistency is less than 1dB. The whole system work normally and stably. The result meets the system requirements.