Design Of Portable Single-frequency Bathymeter System

With the development of science and technology in our country, the exploitation of ocean gradually takes people's attention. Sound which is the foundation of exploiting ocean will be regarded. Echo Sounder who has lots of characters, such as its stabilization and credibility, simple principle, manufacture and so on has definite status in practice. It is very valuable to research its capability.Firstly, development of the state of marine surveying and mapping at home and abroad and the bathymetry and bathymetric applications were introduced in this paper. And the principle of Sounder was described in detail. Secondly, the main performance indicators of the system were determined according to the actual application. And in accordance with the echo sounder system performance requirements, the overall design of the system was completed.In this paper, the design and implementation of hardware part of the sounder system was shown. The hardware of the sounder system was composed of transmitters, receivers, data processing circuit, display control, send and receive combined replacement transducer and power module and so on. Specially, the transmitter was made up of the gate driver circuit and the D class power amplifier circuit. And the receiver was made up of the preamplifier circuit, band-pass filter, controllable-gain amplifier circuit and the analog-digital conversion circuit. The data-processing circuit was mainly based on FPGA and DSP processor architecture.The software of the sounder system was designed in this paper, including implementation of transmit system, gain control, signal acquisition, signal processing and storage, in-depth displays. Specially, signal acquisition and signal processing was described in more detail.Lastly, the shell of the sounder system was made, and the sounder system was assembled and tested with the pool experiment. The test error source was analyzed and the improvements were suggested in this thesis.