多极化大地电磁系统及其在金属矿勘探中的应用

Multi-polarized magnetotellurics system and its application to the exploration in metal mines

大地电磁法在矿产资源勘查、自然灾害监测预警、工程勘探等领域发挥着不可或缺的作用。鉴于目前国内市场大地电磁仪大多为国外进口,研制具有自主知识产权的大地电磁仪需求迫切。多极化大地电磁法同时采用多组不同极距观测同一方向上的电场,从而获得不同空间范围的电场信息,提高测深准确度。多极化大地电磁系统采用一套电磁场传感器观测1~105 Hz频段的天然电磁场,实现2000 m以浅测深;其具有2磁道、3电道,既可以实现多极化大地电磁法观测,也可以实现传统的大地电磁法矢量或标量观测;系统配套的数据采集软件和数据处理软件界面友好,功能齐全,方便操作。通过多通道、多仪器一致性检测,并与国外仪器对比,表明仪器性能良好。在某金属矿勘查中的成功应用,表明该系统具有应用前景,可推广使用。

Magnetotellurics plays an indispensable role in the exploration of minerals,the monitoring of natural disasters,and engineering prospecting.At present,most of the magnetotellurics instruments in the domestic market are imported from abroad.It is urgent to develop magnetotellurics instruments with independent intellectual property.Multipolarized magnetotellurics applies multiple sets of electrodes of different spacing to observe the electric field in the same direction,which obtains electric field information of different spacing ranges and helps improve the detection resolution.The paper introduces a multi-polarized magnetotellurics system.The system applies a set of electromagnetic field sensors to observe the natural electromagnetic fields within the range of 1-105 Hz,and can be used to realize the 0-2000 m detection.The system possesses 2 magnetic channels and 3 electric channels,making it possible to observe multi-polarized magnetotellurics while to observe the vector and scalar of traditional magnetotellurics;the data acquisition software and data processing software are user-friendly,functional and easy to operate.Through multi-channel and multi-instrument consistency detection,and the comparison with overseas equipment,the system has good performance.The successful application in a metal mine prospecting shows that the system is promising in the application and can be widely used.