编码源地电观测对干扰信号的抑制试验——以通渭台观测为例

随着城镇化进程加快使中国的部分地面电阻率观测台站遭受到严重的电磁干扰，导致地电阻率测量产生了较大的误差，淹没了地震引起的地电阻率变化。本文选取通渭地震台，通过运用编码源地电阻率观测技术和循环互相关计算方法，改变发射序列信号周期（观测时间长度）和测量叠加次数使激发极化效应更加充分，有效地抑制环境随机噪声，在高铁、基建等干扰运行或活动时段获得离散度较小的地电阻率数据。这种新的地电阻率观测体系，对现有地面地电阻率台站持续发展提供了技术保障，能为地震预报与科学研究提供可靠的数据。

Experiment on Restraining Interference Signal by Coded-Source Geo-electricity Observation: A Case Study of the Observation at Tongwei Station

In past earthquakes, we found that the change in the observed geo-resistivity is an effective basis for earthquake prediction. In recent years, the acceleration of urbanization has caused serious electromagnetic interference to some observation stations, resulting in a large error in geo-resistivity measurements. In this study, Tongwei station, Gansu Province, was selected as a case study. Various complex electromagnetic interferences are present near the station, such as high-speed railways, highways, buildings, and power consumption by industrial production. Here, the coded-source earth resistivity observation technology and the cyclic cross-correlation calculation method were used, and the transmission sequence signal cycle (observation time length) was changed to make the excitation polarization effect more adequate. The results showed that the environmental random noise could be effectively suppressed. Moreover, geo-resistivity data with small dispersion could be obtained under the interference of high-speed railway and infrastructure. This new geo-resistivity observation system can provide technical support for the sustainable development of existing geo-resistivity stations and reliable data for earthquake prediction and scientific research.