The Research Of The Geomagnetic Variation Field In The Geomagnetic Navigation

In recent years, navigation technology has an increasingly important position in thecivil and military. Especially geomagnetic navigation technology, for its passive, noradiation, low energy consumption, and also because it can work throughout all the dayand all terrain, geomagnetic navigation technology has gained rapid development. Butthere are still three major factors in restricting the development and application of thegeomagnetic navigation technology. The first one is the establishment of thegeomagnetism database used to match the measuered data. The second one is thereal-time measuerment of the geomagnetic detector. The third one is the research of thegeomagnetic matching algorithm. In this thesis we analyze the influence of geomagneticvariation field on the geomagnetic navigation. The main content is as follows.Firstly, the basic theory of the geomagnetic field is introduced, the composition andorigin of the geomagnetic field is analyzed, and the distribution characteristics of thegeomagnetic elements is also analyzed and summarized. At the same time, the research ofthe analytical mode of the geomagnetic field is done.Secondly, the long-term change and short-term changes of the geomagnetic field areintroduced, and the influence of the geomagnetic variation field on the geomagneticnavigation is summarized. Then the influence of the long-term changes of thegeomagnetic field on the geomagnetic reference map is analyzed and the method of thecorrection of the geomagnetic reference map based on the rate of the long-term changes isproposed. And then the preparation of the revised geomagnetic reference map by comupterprogram is achieved.Thirdly, the influence of the short-term changes of the geomagnetic field on thegeomagnetic navigation is studied. And then a detailed analysis of the composition of theshort-term changes of the geomagnetic field is proposed. The regular components of the changes of the short-term geomagnetic field changes are analyzed, and this componentsconstitute the daily alternating magnetic field.At last, the daily alternating magnetic field model is proposed base on Fourier spectralanalysis. The model use the least squares method for simulation. Compared with thepolynomial simulation, it confirmed the rationality and the feasibility of the dailyalternating magnetic field model. Also the residual analysis of the measuerd data isproposed for the model further validation. At the end of this thesis, the defects of themodel as well as the variou factors during the experiment and the further researchprospects are proposed.