纳伏级微弱信号的检测理论与实现测试计量技术及仪器专业论文.docxVIP

优秀毕业论文 精品参考文献资料 中文摘要论文题目： 中文摘要 论文题目： 纳伏级微弱信号的检测理论与实现 专 业： 测试计量技术及 硕士生： 张丽萍(签名) 指导教师： 张家田(签名) 摘 要 过套管地层电阻率测井是通过测量套管上三个电极间的微小电压降来计算地层的漏 电流，进而计算出地层的视电阻率。套管三个电极上的电压降是微伏级信号，其二阶差分 电压为纳伏级极微弱信号。 微弱信号检测是测量技术中的高尖端技术，由于它能测量传统观念认为不能测到的 微弱量，所以得到了迅速的发展和重视。 本文分析了微弱信号检测的各种方法，采用了相敏检波算法来检测过套管地层电阻 率测井的微弱信号。首先，通过仿真来验证相敏检波算法在过套管电阻率测井微弱信号 检测中是可行的。其次，本文给出了相敏检波的具体算法，以及通过微弱信号数据处理 软件，进行算法移植和联机调试。本文还介绍了抗干扰技术，并设计了带通滤波器。 实验结果表明：在强噪声背景下，采用相敏检波方法，可以很好地抑制噪声，实现 小信噪比下的微弱信号幅度的精确测量。 关键词：过套管测井微弱信号检测 相敏检波数字滤波 论文类型：基础研究 (本文得到中国石油天然气集团公司中青年创新基金项目(编号：05E7039)的资助) Subject： Subject： The Theory and Implementation of Nanovoit Weak Signal Speciality： Measu strument Name： Zhang Instructor：Zhang ABS’I’RAC。l’ Cased hole formation resistivity logging technology is to measure the micro—voltage of the three metrical electrodes of cased hole to compute current leak-current and the resistivity of the earth．The voltage of the metrical electrodes is microvolt and the major work of this paper is to complete the detection of the extremely weak voltage signal of the metrical electrodes of the cased hole，but its second voltage difference is nanovolt． Weak signal detection is one of the most advanced techniques．Because it call measure the feebleness signal which Was not considered by traditional conception·s0 it get fast development and recognition． In this paper，the author analyzes the method of weak signal detection，and a pbase．sensitive detection method of weak signal detection Was adopted．Firstly，the simulation experiments which were educed by phase-sensitive detection of cased hole formation resistivity ale presented，and it validates that it is feasible under this environment．Secondly， this paper shows the material arithmetic of phase—sensitive detection，and through the data processing software of weak signal， and then use arithmetic transplant to accomplish online debugging．In this paper,the author introduces the anti-interference technology and designs the band—pfiss fi lter． The results indicate that in strong noi