伪随机编码磁性源瞬变电磁发射技术及电磁响应分析  

Pseudo-random coded magnetic source transient electromagnetic emission technology and electromagnetic response analysis

作　　者：石琦 刘丽华 倪志康 刘小军 方广有 SHI Qi;LIU Lihua;NI Zhikang;LIU Xiaojun;FANG Guangyou(Aerospace Informatory Research Institute,Chinese Academy of Sciences,Beijing 100000,China;Key Laboratory of Electromagnetic Radiation and Sensing Technology,Beijing 100000,China;School of Electronic Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100000,China)

机构地区：[1]中国科学院空天信息创新研究院,北京100000 [2]电磁辐射与探测技术院重点实验室,北京100000 [3]中国科学院大学电子电气与通信工程学院,北京100000

出　　处：《中南大学学报（自然科学版）》2020年第5期1268-1278,共11页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划(973计划)项目(2018YFF01013300);国家自然科学基金资助项目(61827803)。

摘　　要：为了设计一种伪随机编码磁性源瞬变电磁系统,从关键技术和电磁理论方面讨论该系统的设计与该系统在均匀半空间大地模型下所使用的正反演方法。首先对比分析4种伪随机编码的特性,从中选择m序列作为系统的激励信号;然后,基于有源恒压钳位技术设计系统发射电路,正演出实测数据的电磁响应。根据m序列伪随机编码系统辨识理论,响应波形经预处理后得到大地脉冲响应估计值并与标准值比较。研究结果表明:该磁性源瞬变电磁系统可以克服感性负载的阻碍作用,发射出波形质量高的伪随机编码电流;若电流波形的自相关性好,即使电流波形出现一定程度失真,仍可以获得与理论值很接近的大地脉冲响应估计值,预处理结果不完全依赖伪随机编码电流波形。In order to design a pseudo-random coded magnetic source transient electromagnetic system,the design of the system and the forward and inverse methods used by the system in a uniform half-space earth model were discussed from the perspective of key technologies and electromagnetic theory.First,the characteristics of the four kinds of pseudo-random codes were compared and analyzed,and the m sequence was selected as the excitation signal of the system.Then the system transmission circuit was designed based on the active constant voltage clamping technology to perform the electromagnetic response of the measured data.According to the identification theory of the m-sequence pseudo-random coding system,the response waveform was preprocessed to obtain the estimated value of the earth impulse response and compared with the standard value.The results show that the magnetic source transient electromagnetic system can overcome the obstruction of inductive loads and emit a pseudo-random coded current with high waveform quality;if the current waveform has good autocorrelation,and even if the current waveform is distorted to a certain degree,the estimated value of the earth impulse response that is very close to the theoretical value can be obtained,and the preprocessing result does not completely depend on the pseudo-random coding current waveform.

关 键 词：伪随机编码 磁性源 瞬变电磁 辨识方法 维纳滤波 

分 类 号：P631[天文地球—地质矿产勘探]