The Feasibility Study Of A New ADCP Mathematical Model

The 21st century is the century of ocean. With the development of the road of the powerful ocean, it is bound to put forward higher requirements to the ocean of intell-igent instruments.The main content of this study is derivated from marine monitoring technology,which is a part of the project, "multi-parameter marine environment det-ection buoy"under China national 863 programs. The main task of this paper is to verify a new method for measuring the Doppler Shift and to study the feasibility of measuring which can be applied to the ADCP(Acoustic Doppler Current Profiler) system. The new measurement method is the core of this ADCP system.ADCP (Acoustic Doppler Current Profiler) is the most advanced flow velocity measurement equipment in the word. At the same time,the projects have brought great convenience to the hydrologists,environmental protection departments,civil and hydraulic engineering. In recent years,with the rapid development of embedded technology, China’s Acoustic Doppler Current Profiler has made great achievements, and achieves good results in real-time and fast processing. But now our country has not owned the ADCP which can be used in the commercial application,so it is imminent to develop the stable, reliable and flexible business-use products.This article finally has carried on the preliminary experimental verification. With comparing the received and theoretical waveforms,it verifies the feasibility of the proposed mathematical model of the paper,and points out the shortcomings of the system and the future research directions.This dissertation achieves the following main work and innovative points:1. Analyzing the principle of ADCP measurement based on Doppler effect. It applies the verified measuring Doppler Shift to the system ADCP. This method can reduce the influence of the underwater noise on the measured signal.2. The system gave a method of system modeling after theory validation, and verified the reliability and feasibility of the new ADCP system. The mathematical model simplifies circuit design and it improves the flexibility of the subsequent circuit.3. Design of the transmitting circuit. The transmitter circuit uses a DDS (direct digital synthesis) technology which can produce complex chirp signal. It can precisely control the stepping frequency and its sweep time. This is just to meet the requirements of the transmitted signal in this paper.4. Design of receiving circuit. The receiving circuit adopts a complex integrated resonant circuit so that it simplifies the structure of the circuit. What’s important is that this compact structure can improve SNR.