Study On New Geomagnetic Velocity Measurement Based On Geomagnetic Data

A new correlation velocity measurement based on geomagnetic data is proposed, which aims at satisfying requirements of autonomous navigation system with long endurance and high precision. This thesis lucubrates the key technologies of the geomagnetic velocity measurement system, including time series similarity searching algorithm, geomagnetic measurement techniques, geomagnetic data interpolation techniques and error analysis techniques of the geomagnetic velocity measurement system, and makes some research achievement. At the end of the thesis, the correctness and technical feasibility of the results are verified by the geomagnetic velocity measurement experiments.The researches of this thesis are as follows:1. By analyzing the physical characteristics of the geomagnetic field, the composition of the geomagnetic field and different geomagnetic field models are introduced. The basic principle and key technology of the geomagnetic velocity measurement are proposed based on the character of the geomagnetic field and correlation velocity measurement techniques.2. Several traditional searching algorithm of time siries are introduced, and the suitability of three kinds of methods in geomagnetic velocity measurement, which include distance measurement algorithm, maximum coefficient algorithm, frequency domain algorithm, is analyzed, and the suitability and effectiveness of DFT are verified.3. The thesis analyses the origin of the error in the geomagnetic velocity measuement system, and the effects of each error are studied. The corresponding error control techniques are proposed. The optimization design method of sensor distance, sample rate and correlation length is given. A data preprocessing method is proposed, in which the outliers are restrained by moving average. Several spatial interpolation methods are used in the geomagnetic velocity measurement system. The effectiveness of the error control techniques is verified by simulation.4. A geomagnetic velocity measurement system is set up in this thesis. The feasibility of geomagnetic measurement techniques, geomagnetic data interpolation techniques, the analysis method of the correlation algorithm and the error depressing techniques are verified by land experiment. The result shows that geomagnetic velocity measurement is an effective and feasible autonomous method with good hideness and no accumulation error caused by time. In conclusion, the geomagnetic velocity measurement method proposed in this paper provides a new idea for underwater vehicles to implement automatic navigation with long endurance and high precision.