分布式电磁法仪器系统设计及实现

本文介绍一种采用大功率稳流发射、低噪声测量、宽频带接收以及分布式同步等技术，自主研制的分布式多功能电磁法仪器系统.系统包括大功率电磁法发射机、分布式电磁法接收机、磁场传感器、整流源等设备.采用ARM芯片和FPGA芯片进行发射机的整机控制和信号整形发射，采用PC104工控机和FPGA芯片进行接收机的整机控制和信号处理.在人工场源模式下实现了可控源音频大地电磁法（CSAMT）、谱激电法（SIP）和时域激电法（TDIP）等测量功能；在天然场源模式下实现了大地电磁法（MT）、音频大地电磁法（AMT）的测量功能.发射机在满功率发射的情况下连续可靠运行时间大于12 h，接收机的动态范围大于120 dB，接收机可接收信号频率范围是0.001 Hz~32 kHz.通过典型矿区的野外实验和应用，表明本系统的性能总体上达到了国际先进水平.

Design and realization of the distributed electromagnetic instrument system

This paper presents a distributed multi-function electromagnetic system developed by using the technology of high-power and steady current emission, low noise measurement, broadband reception, and distributed synchronization. The system consists of a high power electromagnetic transmitter, distributed electromagnetic receiver, magnetic field sensor, rectifier source and other equipment. It uses ARM chip and FPGA chip to control the transmitter and signal shaping, and PC104 industrial control computer and FPGA chip to complete the receiver's whole machine control and signal processing. On a artificial field source model, the measurement functions of controllable source audio-frequency magnetotelluric (CSAMT), frequency domain induced polarization (SIP) and time domain induced polarization (TDIP) are realized. On a natural source model, the measurement functions of magnetotelluric (MT) and audio magnetotelluric (AMT) are also realized. The transmitter can run for more than 12 hours in the case of full power transmission. The dynamic range of the receiver is greater than 120dB. The receiver can receive the signals from 0.001 Hz to 32 kHz. Field experiments and application to a typical mining area show that the performance of this system has reached the international advanced level overall.