基于IGRF13和WMM2020模型的地磁匹配特征量的选择

Selection of geomagnetic matching feature elements based on IGRF13 and WMM2020 models

地磁导航具有极好的自主性、隐蔽性以及抗干扰性,而且近几年越来越引起广泛的关注和研究.在地磁匹配导航系统中,地磁特征量对导航性能有极大的影响,而且特征量数据之间有较大的差异,因此选择最佳的地磁匹配特征量是实现高性能地磁匹配导航的重要任务.本文采用了最新的国际地磁参考场模型IGRF13与世界地磁模型WMM2020研究分析了地磁场分量随时间及空间的变化情况,进而选择出匹配效果最佳的地磁匹配特征量.首先基于两种模型数据,通过用坡度的概念来描述导航区域的七个地磁匹配特征量随空间变化的情况,最终排除坡度较小的角度类地磁场特征量;其次,因地磁场的时间变化分析可以从点和区域两个方面进行,故采用控制变量法,分别计算出两个模型的单点以及区域的地磁信息熵值,以此来分析地磁匹配特征量随时间变化的情况.然后,通过基于两种地磁模型数据的计算与分析,结果均发现垂直分量Z是最佳的地磁特征量.最后,在导航区域分别基于模型数据和实测数据进行定位实验,进一步验证了分析的结果,为地磁匹配导航提供了可靠的依据.

Geomagnetic navigation has excellent autonomy,concealment and anti-interference,and has attracted more and more attention and research in recent years. In geomagnetic matching navigation system,geomagnetic feature element has a great influence on navigation performance,and there are great differences among feature data. Therefore,selecting the best geomagnetic matching feature element is an important task to achieve highperformance geomagnetic matching navigation. In this paper,the latest IGRF13 and the WMM2020 are used to study and analyze the changes of geomagnetic field components with time and space,and then the geomagnetic matching feature element with the best matching effect is selected. Firstly,based on the two model data,the spatial variation of seven geomagnetic matching feature elements in the navigation area were described with the concept of slope,and finally the angular geomagnetic feature elements with smaller slope were excluded;Secondly,since the time variation analysis of geomagnetic field can be carried out from two aspects:point and region,the control variable method is adopted to calculate the geomagnetic information entropy of single point and region of the two models respectively,so as to analyze the variation of geomagnetic matching feature elements with time. Then,through the calculation and analysis of data based on two geomagnetic models,it is found that the vertical component Z is the best geomagnetic feature element. Finally,positioning experiments are carried out based on model data and measured data in the navigation area,which further verifies the analysis results and provides a reliable basis for geomagnetic matching navigation.