m序列的功率谱密度分析,兼论伪随机信号电法仪的抗干扰性  

Analyze the power spectral density of the m sequence and discuss the anti-interference ability of instruments for electrical and electromagnetic prospecting using pseudo random signal

作　　者：罗延钟[1] 陆占国 孙国良[3] 王寒冰 高隆钦 LUO YanZhong;LU ZhanGuo;SUN GuoLiang;WANG HanBing;GAO LongQin(China University of Geosciences,Wuhan 430074,China;Beijing Orangelamp Geophysical Exploration Co.,Ltd.,Beijing 102200,China;Beijing University of Aeronautics and Astronautics,Beijing 100083,China)

机构地区：[1]中国地质大学,武汉430074 [2]北京桔灯地球物理勘探有限公司,北京102200 [3]北京航空航天大学,北京100083

出　　处：《地球物理学进展》2023年第2期839-845,共7页Progress in Geophysics

摘　　要：近年来,基于伪随机信号系统辨识的“伪随机信号电法仪”受到广泛关注.普遍认为,伪随机信号电法仪具有两大优点:抗干扰能力强和一次观测便可获得大地阻抗频谱的高效性.本文基于对m序列的功率谱密度的计算和分析,探讨了伪随机信号电法仪的抗干扰性能.结果表明,至少对于频率域伪随机信号电法仪来说,与采用正反向连续方波的传统频率域电法仪相比,在相同供电电流强度条件下,其有效信号强度大约降低√N*2/π倍(N是m序列的位数);伪随机信号电法仪一次观测获得多频点频率响应的高效性,是以降低各个频点上的有效信号强度为代价的.这都不利于提高仪器的抗干扰性能.In recent years, the instruments for electrical and electromagnetic prospecting using pseudo random signal are attracted a wide spread attention. It is pointed by the textbooks and many literatures, that the outstanding advantages of these instruments are of a strong anti-interference ability and of the high-efficiency for obtaining the frequency spectra of earth's impedance by once observation. Based on the calculations and analysis of the PSD(power spectrum density) of m-sequence, the anti-interference ability of these instruments was discussed in this paper. Result is at least for the instruments of electrical and electromagnetic prospecting using pseudo-random signal in frequency domain, at the same condition of supply current strength, the effective signal strength would √N*2/π times less than that for the conventional instruments of electrical and electromagnetic prospecting using square wave supply current. So the high-efficiency of the instruments in frequency domain using pseudo-random signal(to get the frequency response of the earth system at many frequency points just by once observation), would at the cost of lower effective signal strength at each frequency point. It should not benefit to improve the anti-interference ability of the instrument.

关 键 词：电法勘查 观测仪器 伪随机信号 系统辨识 

分 类 号：P631[天文地球—地质矿产勘探]