Design And Implementation Of Data Acquisition System In Imaging Sonar

High-resolution sonar imaging technology has important significance to detect seabed topography and the surface information of underwater objects such as the dam, the hull and the buildings. It has wide application prospect in underwater positioning and underwater photography. The analog signal pretreatment and data acquisition technology is studied in this thesis, and the hardware and the software of imaging sonar are also developed.Module structure is used in receiver to complete signal amplification, filtering, gain adjust and other signal conditioning work. In order to get excellent amplitude and phase consistency among 160 channels, many factors are taken into account in the process of the receiver design. FPGA is adapted as the core processing chip to achieve digital acquisition control circuits, including ADC conversion circuit, CF card storage circuit and LVDS transmission circuit. At the same time, various parts of functional modules software programs are compiled by VHDL (VHSIC Hardware Description Language). Communication is also accomplished between the acquisition systerm and the main control unit to realize the gain, sample rate and other adjustment commands interaction.In addition, in based of analysis of signal integrity theory, analog-to-digital hybrid circuits are taken shielding, isolation, reasonable grounding, power supply filtering and other measures to effectively reduce the crosstalk, radiation, impedance mismatch and other signal integrity problems for improving the stability for hardware circuits.Experiments show that the hardware circuits and software programs run well and the predefined requirements are fulfilled.