磁通门磁力仪GM4定向方法的研究

Research on the Orientation Method Using Fluxgate Magnetometer

仪器正确定向是保证仪器观测质量的一个重要环节。由于地磁场的长期变化,仪器需要定期重新定向。本文应用全国44个地磁台站2008—2012年观测数据,研究了各台站D分量的长期变化特征。结果表明,仪器定向位置和被测磁场位置产生较大偏离时,必须重新定向。同时首次提出影响定向精度的零场漂移S0,并根据理论计算在红山地磁台实地开展测量,测量结果表明,零场漂移S0数值达到50.3 n T,超出D分量定向输出范围(磁静日时日变缓慢时间段为-50n T—+50n T)。

Correct orientation of instrument is a key point to assure the observation data. Because of secular variation of the geomagnetic, the instruments need to be re-orientated regularly. Based on the data of 22 geomagnetic observatories in China from 2008 to 2012, we analyze the characteristics of secular variation and annual change about D. Re- orientation is needed for the postion of the instrument orientation is obviously deviating with from the position of the tested maganetic filed. Then a parameter So which decides the precision of orientation is proposed for the first time, and which is observed in Hongsan geomagnetic observatory according to the theoretical calculation. Results show that when So arrives 50.3nT, the output of D will be out of the range from -50nT to ＋50nT.