基于WMM2010磁场模型的磁差算法研究

Study on Magnetic Variation Algorithm of Magnetic Model Based on WMM2010

随着现代航海仪器的发展，人们对磁罗经的利用已越来越少，但当现代航海仪器失效时，高可靠性、低成本的磁罗经就彰显其重要性了。然而由于磁差和自差的存在，磁罗经的指向精度受到很大影响，因此，磁差的修正和自差的校正显得尤为重要。文章以世界磁场模型WMM2010所求出的磁差值为基准值．将从海图上获得的磁差值和GPS读取的磁差值与该基准值比较，分析误差产生的原因及方法的适用性，为驾驶员在使用两种常用方法时提供参考。

With the development of modem navigational equipment, the magnetic compass is seldom used. But when the modern navigational equipment is invalidated, the magnetic compass shows its high reliability. However, due to variation and deviation of the magnetic compass, the accuracy of indicating the course is greatly affected. So the correction of variation and amendment of the deviation is very important. In this paper, the variation obtained from WMM2010 as the norm value is compared with the variation obtained from the navigational charts and readings from GPS to analyze the reasons of the error and the applicability in order to provide references for the officers on watch.