【作者】 马超；

【导师】 王君；

【作者基本信息】 吉林大学 ， 检测技术与自动化装置， 2015， 硕士

【摘要】 伪随机编码是一种按照事先制定好的伪随机函数，根据作业需要生成相应的伪随机信号的编码方式，产生的伪随机信号具备多阶主频，伪随机信号一次供电多阶主频的特点可以帮助高密度电法克服极化效应带来的影响，由这些具备多阶主频的信号可以计算出同一频率的相对准确的视电阻率、百分频散率等地探参数，从而在推算地址体结构以及地表以下矿体的种类和分布情况时起到极大的作用。目前国内外的高密度电法设备种类繁多，但是总的来看发射技术非常相似，多采用占空比为1：1的方波信号。直流电法无法克服接地电极极化产生的极化效应所带来的影响，无法得到相对准确的极化率，常规的直流高密度电法为了得到相对准确的极化率，一般都配备两套电极系统，即一套发射电极和一套测量电极，成本高、操作复杂、仪器笨重、野外实验不方便、故障率高等等缺点使得直流高密度电法仪器使用起来有诸多不便。本文对伪随机编码如何在高密度电法测量的实现进行了详尽研究，主要包括人机交互界面设计部分，伪随机信号生成部分，数据处理及计算相关参数部分，电阻试验及阻容试验分析部分，结果验证部分。以上几个部分为本文主要研究内容。伪随机信号生成部分。伪随机信号生成部分介绍了伪随机编码的编译规则及其生成原理，三阶、五阶、七阶伪随机信号的生成及其傅氏频谱，推算发射机使用的伪随机信号三个部分，伪随机编码的编译规则是取自何继善院士的在《广域电磁法和伪随机信号电法》中提到的伪随机函数，其生成原理类似于二进制数的某种加法规则，发射机使用的伪随机信号是由-1、0、1三个数字码组成的信号。上位机部分。上位机是用C++程序语言设计出来的，使得操作者通过操作微型计算机与高密度电法仪进行通信的可执行程序，该程序由Microsoft Visual Studio2005设计平台开发，可兼容xp、vista、win7等运行环境，该程序包括参数设置部分，示波器显示部分，仪器返回信息显示部分，以及操作者操作部分。上位机可命令仪器实现编号操作、不同方式的跑极操作，可调整示波器显示时横轴和纵轴的长短，可自由设置数据存储目录，可添加自定义跑极方式等等。数据处理及计算相关的地电参数。该部分是将测量数据从上位机程序保存的二进制文件中提取出来，进行一系列的处理之后，将单位换算成真值，然后算出电阻率，根据得到的相应阶次的主频，推算相应阶次的百分频散率。电阻串试验及阻容试验分析部分。经过一系列理论分析之后，根据电阻串实验得到的数据对比理论值，得出将伪随机编码应用在高密度电法中，能够完成对百分频散率的测量的结论。更多还原

【Abstract】 Pseudo random coding is a kind of according to the set in advance good pseudo-randomfunction, according to the operation need to generate the corresponding pseudo random signalencoding, the pseudo random signal has many order frequency, a pseudo random signal powersupply, multistage frequency characteristic can help high density resistivity method to overcomethe effects of polarization effect, by these have order frequency of the signal can be calculatedmore relatively accurate apparent resistivity of the same frequency, percentage dispersion rate,phase difference and other parameters, the address according to structure and types anddistribution of ore bodies below the surface play a great role.Various types of high density resistivity method and equipment at home and abroad, but onthe whole transmission techniques are very similar, with the duty ratio of1:1square wave signal.Dc grounding electrode polarization insuperable produced by the effects of polarization effect,can’t get a relatively accurate polarization, the conventional dc high density electrical method inorder to get relatively accurate polarizability are usually equipped with two sets of electrodesystem, namely a set of emission electrode and a set of measuring electrode, high cost, complexoperation, instrument bulky, field experiment is not convenient, high failure rate, and so onshortcomings make dc high density resistivity method and instrument have many inconvenienceto use.In this paper, the pseudo random coding in the high density resistivity method to measure theimplementation of research is introduced detailed, mainly including the human-computerinteraction interface design part, pseudo random signal generating section, the data processingpart and calculate relevant parameters, resistance test and resistance capacity test analysis section,the results section. More than a few part is the main research contents in this paper.The human-computer interaction interface part. The interface is designed with c++programlanguage, make the operator by manipulating the microcomputers communicate with high density resistivity method and instrument of executable program, the program developed by MicrosoftVisual Studio2005design platform, can be compatible with Windows xp, vista, vin7runtimeenvironment, such as the program includes parameter Settings, oscilloscope display parts,instrument back information display section, and the operator operation part. Thehuman-computer interaction interface can implement numbering command instrument operation,different ways of running operation, adjustable oscilloscope display when the length of thehorizontal axis and vertical axis, are free to set the data storage directory, you can add a customrun extremely way and so on.Pseudo random signal generated. Pseudo random signal generated part introduces thecompilation rules and generating principle of pseudo-random code, the third order, five order,seven order to generate pseudo random signal and its frequency spectrum fu, calculate the launchof the pseudo random signal transmitter three parts, the compilation of the rules for pseudorandom code is taken from ji-shan-he academicians act mentioned in the pseudo-random functionin the book named wide-area electromagnetic method and pseudo random signal electricity, itsgenerating principle similar to a binary number some addition rule, using the pseudo randomsignal transmitter is composed of-1,0,1of three digital code signal.Data processing and calculate relevant parameters. This part is to save measurement datafrom the man-machine interface of binary files extracted, after a series of processing, unitconversion come true value, and then calculate the resistivity, according to the correspondingorder of frequency, calculate the percentage of the corresponding order dispersion rate, phasedifference and other parameters.Resistance test and resistance capacity test analysis section. After a series of theoreticalanalysis, according to the resistance string data from the experiment comparing the theoreticalvalue, draw the conclusion.更多还原