Design Of Receiver And Acquisition System For Multi-beam Bathymetric Sonar

Multi-beam bathymetric sonar is a device that can detect the depth of sea and lake, it is widely applied in the area such as seafloor landform detecting and marine environmental monitoring. This paper is based on some Multi-beam bathymetric sonar, researching the receiving-collecting system and the preprocess logic is done.In This paper, the principle and the status quo of the Multi-beam bathymetric sonar is introduced, the system of the Multi-beam bathymetric sonar is analyzed. Considering the use,the design demand of receiving-collector system is put forward, some specific work is carried out in the following aspects.Firstly, the design indicator of one hundred channels in the receiving circuit is determined, the plan of the circuit system is designed. Introducing the signal noise, studying the noise character of the electronic component, designing the low noise receiving circuit. In order to reduce the noise of the power, some filter is designed. When selecting the controllable gain chip,the AD8336 is introduced, the circuit of controllable gain is accomplish. When designing the band-pass filter, the structure of the MFB and Sallen-key is introduced and compared, some operational amplifier is also compared. The MFB band-pass filter and AD8032 is adopted. Fixed gain amplifier circuit is designed and considering the consistency of the channels.Then the plan of the Multi-beam bathymetric sonar collecting system is made. The A/D converter , D/A converter, and FPGA is involved in the system, FPGA is used as a controller,A/D converter is used for converting the analog signal to digital signal. D/A converter is used for converting the digital signal to analog signal and control the controllable gain circuit which is used in the receiving circuit. In the paper, the FPGA is introduced, analyzing and selecting the function chip in the A/D and D/A circuit, designing the relative A/D and D/A circuit, in the D/A converter, single-ended differential circuit is also designed, converting the single signal to differential signal.Lastly the logic of pre-process and the tests of the receiving and collecting circuit are accomplished, the indicators reach the expected requirements.