基于STA/LTA的瞬变电磁响应采集方法  

STA/LTA based method for transient electromagnetic response acquisition

作　　者：张宇 胡杰 Zhang Yu;Hu Jie(College of Information and Computer,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学信息与计算机学院,太原030024

出　　处：《国外电子测量技术》2023年第6期17-22,共6页Foreign Electronic Measurement Technology

基　　金：山西省科技重大专项(20121101004)资助。

摘　　要：瞬变电磁(transient electromagnetic,TEM)响应信号的采集是TEM物探中的关键环节,信号的采样质量决定了数据分析与解释的准确性。常规同步式接收机的延时采样方法和非同步式接收机的全波形采样方法往往不具信号识别能力,较差的采集结果常需要进行人工调整,这会为最终结果增加不确定性。针对上述问题,提出了基于短时均/长时均(short-term average/long-term average,STA/LTA)的TEM响应采集方法,结合实测数据进行分析,确定了将短时窗设为40μs、长时窗设为短时窗的10~20倍、选择CF2(n)作为特征函数能够获得较好的识别结果;从信噪比出发,分析了均匀分布噪声、高斯白噪声、单一频率干扰对STA/LTA方法识别率的影响;将STA/LTA算法移植于低功耗接收机进行单次采样与叠加采样测试,结果表明,在两种采样模式下采集的数据有着高的相似性,测试信号的能量比最差为84%,最优为99%,说明STA/LTA方法有着准确识别TEM响应的能力,证明了基于STA/LTA的TEM响应采集方法的可行性。The acquisition of transient electromagnetic(TEM)response is a key aspect of TEM prospecting,because the quality of the signal sampling determines the accuracy of the data analysis and interpretation.The time delay sampling method of conventional synchronous receivers and the full waveform sampling method of non-synchronous receivers often do not have signal evaluation capability,and the poor acquisition results require manual adjustment,which increases the uncertainty of the final results.In order to address the above problem,the TEM response acquisition method based on Short-term average/long-term average(STA/LTA)is proposed,and an analysis is performed with field data to determine that setting the short-term window to 40μs,the long-term window to 10~20 times of the short-term window,and choosing CF2(n)as the characteristic function can obtain better recognition results;the effect of uniformly distributed noise,Gaussian white noise,and single frequency interference on the recognition rate of STA/LTA method is analyzed in terms of SNR;the STA/LTA algorithm was implemented on a low-power receiver for single and superposing sampling tests.The results showed that the data collected in both sampling modes had high similarity,with the worst energy ratio being 84%and the best being 99%,indicating that the STA/LTA method has the ability to identify TEM responses accurately,proving the feasibility of STA/LTA-based TEM response acquisition method.

关 键 词：瞬变电磁 STA/LTA方法 信号识别 信号处理 

分 类 号：TP301[自动化与计算机技术—计算机系统结构] TH763[自动化与计算机技术—计算机科学与技术]