北极地区磁罗经适用能力

针对磁罗经在北极地区的适用能力问题,根据世界地磁模型(World Magnetic Model,WMM)2019,通过分析极区地磁场、地磁场水平分量和磁差等要素在极区的大小分布和变化趋势,以地磁水平分量6 000 nT为界,指出磁罗经在极区的适用范围,特别是东北航道附近海区可正常使用磁罗经;分析"雪龙"号科考船在2017年北极考察的磁罗经和陀螺罗经数据。研究结果表明:地磁水平分量大于6 000 nT的区域,磁罗经是可正常使用的;为保证北极地区正常使用磁罗经,纬度每变化5°,应重新组织校正剩余自差工作;为应对北极地区磁差随经度变化的速率较大的问题,在磁航向转真航向过程中,应根据WMM自动计算并补偿磁差。

Performance of Magnetic Compass in Arctic Region

The distribution and changes of magnetic field in form of its horizontal component and declination in the Arctic region are calculated with WMM(World Magnetic Model)2019 for studying the adaptation of magnetic compass.The places where the earth magnetic horizontal component is above 6000 nT is defined as the usable area of magnetic compasses.The analysis shows that a magnetic compass can work well in the particularly interested sea area near east-north route.The data from the polar research ship"XUELONG"in 2017 is examined to verify the analysis.The study suggests that automatic declination calculation should be performed to correct magnetic course deviation according to WMM and the compass deviation be recalibrated for every 5 latitude change to ensure the reliable operation of a magnetic compass in the arctic region.