Correction Of Geomagnetic Time-varying Field And Its Application On Geomagnetic Navigation

Geomagnetic matching navigation is one of the new guidance systems and turns to a research hotspot in the field of navigation guidance gradually for its advantages such as high positioning accuracy, strong anti-interference, full autonomy, brilliant battlefield adaptability and low cost, which have broad application prospect and receive high attention from experts at home and abroad. Geomagnetic matching navigation is based on the local geomagnetic anomaly. However, the magnetic field is a vector field with macroeconomic stability and microscopic changes, and its dual characteristics of space and time decide that the geomagnetic matching navigation reference map of includes two aspects. Firstly, preparation—accurate description of spatial distribution. Secondly, correction—precise prediction of time changes.Under the aid of the National Natural Science Foundation of China (Conservatism study of geomagnetic reference map), this dissertation focuses on the correction of geomagnetic time-varying field. The main works are as follows:(1) Aiming at the influence of geomagnetic field variations on the reference graph, the concept of geomagnetic reference map conservatism is defined. Qualitative and quantitative researches on geomagnetic time-varying field prove the existence of influence that geomagnetic secular variation and short-term changes have on the geomagnetic reference map conservatism.(2) Considering the difficulties existed in the analysis of reference map conservatism, a method to find the influence on geomagnetic reference map conservatism from the physical properties of different time-varying field through quantitative simulation after analyzing the shape and rules of long-term change, solar quiet daily variation via extracting the data. Finally, corresponding robustness improvement schemes are put forward according to the different influence styles.(3) The geomagnetic matching algorithm is one of the key technologies of geomagnetic matching location. Classical algorithms of terrain matching and gravity matching are applied on geomagnetic matching in this paper. Matching algorithms based on relative extremum and rigid transformation are researched and the shortcomings of both in practical application are analyzed. An improved geomagnetic matching algorithm is proposed based on the iterative closest point algorithm and iterative closest contour point based algorithm. Simulation experiments show that this algorithm is more suitable for engineering application.The achievements in this paper will have positive effects on the geomagnetic field variation correction, which is a key issue that restricts the development of geomagnetic matching guidance and lay certain foundation to put the geomagnetic matching navigation technology into project use as soon as possible.