基于扩频编码信号的高频电磁测深实验研究

High frequency electromagnetic experiment based on spread spectrum coded signals

针对目前市场缺少浅层电磁探测仪器,本文基于扩频编码原理自行设计了高频电磁勘探系统,并进行了浅层地质体探测实验.首先论述了将逆重复m序列扩频产生的编码信号作为场源的优势,基于该编码方案设计了硬件系统;最后在湖南宝山有色金属矿业有限公司尾矿库进行了野外对比实验.实验结果表明,发射装置发射的编码信号频率高、频点密、频带宽;接收装置获取的信号稳定、可靠;发-收数据互相关后具有较强的抗干扰能力,可高效获得丰富的浅层地质体信息;对野外实验数据进行相应处理,得到的二维地电断面结果与已知地质资料相吻合,表明该系统可以应用在浅层地表勘探中,具有观测速度快、分辨率高、抗干扰能力强等优点.

In view of the lack of shallow electromagnetic detection instruments in the current market,this paper designs a high-frequency electromagnetic exploration system based on the principle of spread-spectrum coding and carries out detection experiments of shallow geological bodies.Firstly,the advantages of using the coded signal generated by inverse repetitive m-series spread spectrum as the field source are discussed,and the hardware system is designed based on this coding scheme;finally,a comparative field experiment is conducted in the tailings pond of Hunan Baoshan Non-ferrous Metals Mining Co.,Ltd.The experimental results show that the coded signals emitted by the transmitter are high in frequency,dense in frequency and wide in frequency band;the signals obtained by the receiver are stable and reliable;the transmitter-receiver data have strong anti-interference capability after inter-correlation,which can efficiently obtain rich information of shallow geological bodies;the corresponding processing of the field experimental data and the results of the 2D geoelectric sections obtained match with the known geological data,indicating that the system can be applied in shallow The corresponding processing of the field experiment data and the obtained 2D geoelectric section results are in good agreement with the known geological data,indicating that the system can be applied to shallow surface exploration with the advantages of fast observation speed,high resolution and strong anti-interference ability.