Research On Affection And Modification Of Magnetic Diurnal Variation For Geomagnetic Matching

With the advantages of high autonomy, concealment and no accumulative error, geomagneticmatching navigation has currently become a hot topic in the area of domestic and internationalnavigation, and has a huge military value. However, navigation accuracy is not high enough, whichseriously restricts the significant development and wide application of geomagnetic navigationtechnology. The daily variation of the geomagnetic field during quiet time is one of the main errorsources of geomagnetic matching navigation. Therefore, how to eliminate the affection ofgeomagnetic diurnal variation is a key technology for high-precision geomagnetic matchingnavigation.In this paper, the influence of geomagnetic diurnal variation in geomagnetic matching isanalyzed in details. A relative modification approach based on FMI method and the matchingalgorithm of multiple characteristic parameters is proposed. The results show that the proposedmethod can greatly improve the performance of geomagnetic matching. The specific works are asfollows:Firstly, the physical origin and spatial and temporal distribution characteristics of geomagneticdiurnal variation are specially discussed in Chinese region. In addition, the current research status,key technologies and trend of development of matching algorithm are reviewed.Secondly, the affection of geomagnetic diurnal variation in geomagnetic matching is respectivelydiscussed based on the IGRF11model and the matching algorithm of multi-dimensional featureelements based on point. The former is qualitative investigation, which indicates that the influence isenormous even in the area where geomagnetic changes smoothly. The latter quantitatively analyzesthe affection by geomagnetic quiet data of Beijing Ming Tombs, Lanzhou and GuangzhouObservatories. The results show that the matching positioning error appears similar variationcharacteristics with geomagnetic diurnal variation, and the latitude effect is significant. GuangzhouObservatory has a maximum error of0.189degree on the direction of latitude, and0.492degree onthe direction of longitude.Finally the correction technology combined FMI method and multi-dimensional featurematching algorithm is proposed to eliminate the affection of geomagnetic daily variation. Thematching analysis by geomagnetic observatory data illustrates that the correction method is effective,and the matching positioning accuracy is improved at least an order of magnitude.