井下小区域地磁数值的时域变化与波动分析

A fluctuation analysis in the time domain to the geomagnetic values in the regional underground

井下点位地磁数据采集精度直接影响到井下地磁定位准确度.针对井下小区域磁测数据在不同时域期间波动变化,选取美国FVM400磁力仪在井下实验场中,对6个基准点进行了3个太阳日的地磁数值的监测,通过数据预处理及统计分析了不同监测点的时域地磁数值波动规律.研究结果表明:小区域内单点地磁总场和三轴分量波动规律一致,波动变化表现明显.磁测数值稳定时域为00:00—08:00和16:00—24:00,不稳定时域为08:00—16:00.不同点位地磁数值时域波动数值较小,为20~60 n T,且在12:00达到了极值.同一时段测量不同点位在磁总场扰动值相对稳定,在井下地磁匹配定位时可用航迹数据相邻点做差运算来消除大部分时域变化磁数值扰动影响.

The acquired data accuracy has been a key factor in the underground geomagnetic positioning.To study the geomagnetic data fluctuations during the time domain in underground,the geomagnetic data of the six datum points in three solar days have been monitored by the FVM400 magnetometer in some mine,preprocess and statistical analysis of the different points. The results show that there is a same fluctuation rule between three-component data and geomagnetic total field of single point,which is the measured stability time domain of00： 00—08： 00 and 16： 00—24： 00,and the instability time domains is 08： 00—16： 00.There is slight differences which range from 20 n T to 60 n T,and reach the maximum fluctuation at 12 o＇clock.It is relatively stable to measure the data fluctuation at multiple points during the same time,differences of the geomagnetic data of the adjacent points which eliminate most of the impact of the time domain fluctuation in the underground geomagnetic positioning.