小波包软阈值降噪法在航空γ能谱中的应用  

Apply wavelet packet soft threshold noise reduction method to aviation gamma energy spectrum

作　　者：张松[1] 胡传皓 李承洋 王楠 严磊[1] 李雪刚 曾国强[1] 顾民[1] ZHANG Song;HU Chuanhao;LI Chengyang;WANG Nan;YAN Lei;LI Xuegang;ZENG Guoqiang;GU Min(Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]成都理工大学,成都610059

出　　处：《核技术》2022年第9期58-64,共7页Nuclear Techniques

基　　金：国家重点研发计划项目(No.2017YFC0602100);国家自然科学基金青年基金(No.11905020);四川省重大科技专项(No.2020ZDZX0007)资助。

摘　　要：随着核技术的不断发展,放射性物质勘探对航空γ能谱仪的探测精度要求越来越高,同时,小波包软阈值降噪法具有降噪效果好、信噪分辨率高等优势。因此,本文使用了多种小波包软阈值降噪方案对使用CeBr_(3)探测器获得的航空γ能谱进行降噪处理,通过比较峰值信噪比大小以及观察降噪对准确度的提升效果,选出了最优的降噪方案。结果表明:最优降噪方案是使用db14母小波进行7层分解的小波包软阈值降噪法,该降噪法将航空γ能谱的峰值信噪比从23.22 dB提升到了39.50 dB,将航空γ能谱仪测量的准确度提高了3.19%。该小波包软阈值降噪法的降噪效果好,失真少,还能够提升测量准确度,适合应用在航空γ能谱的数据处理中。[Background]With the continuous development of nuclear technology,radioactive material exploration requires higher and higher detection accuracy of aerial gamma energy spectrometer,meanwhile,the wavelet packet soft threshold noise reduction method has the advantages of good noise reduction effect and high signal-to-noise resolution.[Purpose]This study aims to find the optimal wavelet packet soft threshold noise reduction scheme for the aerial gamma energy spectrum.[Methods]First of all,the aerial gamma energy spectrum obtained by CeBr_(3) detector was taken for noise reduction study using various wavelet packet soft threshold noise reduction scheme schemes.Then three noise reduction schemes were selected on the base of the peak signal-to-noise ratio(SNR)and applied to the accuracy measurements.Based on the improvement effect of the three noise reduction schemes on the accuracy,the best noise reduction scheme was finally found.[Results]The best noise reduction scheme is a wavelet packet soft threshold noise reduction method using db14 for 7-layer decomposition.This noise reduction scheme can improve the peak signal-to-noise ratio of the aviation gamma energy spectrum from 23.22 dB to 39.50 dB and improve the measurement accuracy of the aviation gamma energy spectrometer by 3.19%.[Conclusions]The wavelet packet soft threshold noise reduction method has good noise reduction effect,less distortion,and can also improve the accuracy of the measurement,which is suitable for application in the data processing of aviation gamma energy spectrum.

关 键 词：Γ能谱 降噪 小波包 软阈值 

分 类 号：TN713[电子电信—电路与系统] TL81[核科学技术—核技术及应用]