直感式磁罗经一纬度上自差校正的适应范围

Application scope in latitude of deviation calibration of geomagnetic compass

磁罗经自差中含有不随磁纬度变化和随磁纬度变化两部分,而在某一纬度进行的自差校正仅消除了不随磁纬度变化的部分;随地理纬度或磁纬度变化导致的自差发生变化部分并没有得到有效的消除。因此,磁纬度变化在一定程度上影响了磁罗经的正常使用,必须对在完成一次自差校正后,自差系数能够适应的磁纬度范围进行研究。基于磁罗经自差理论中的泊松方程,分析和研究了直感式磁罗经由于磁纬度变化导致航向产生误差的问题,提出了在给定指向误差的前提条件下,建立了完成一个纬度上自差校正后自差系数的磁纬度适应范围的分析方法。理论分析和实测试验结果表明,所建立的自差系数与航向误差间关系,对于为把握自差校正时机和正确使用自差系数数据提供了可靠的理论依据。

The deviation of geomagnetic compass includes two parts： One part varies with the magnetic-latitude＇s transformation, and the other part does not. But the deviation calibration in certain latitude only eliminates the latter part. So, the magnetic-latitude＇s changing influences the normal use of geomagnetic compass, and a research must be made on the deviation factors＇ application scope after a deviation calibrating. Based on the magnetic compass deviation theory of Poisson equation, we analyze and study the heading error of geomagnetic compass after a latitude deviation calibrating, and offer the magnetic latitude application scope of the latitude deviation on permissible pointing error. The result shows that the relationship between certain deviation factors and heading errors offer a reliable theory basis for grasping the deviation calibrating time and properly applying the latitude deviation calibration data.