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

Abstract

BackgroundWith 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.PurposeThis study aims to find the optimal wavelet packet soft threshold noise reduction scheme for the aerial gamma energy spectrum.MethodsFirst of all, the aerial gamma energy spectrum obtained by CeBr3 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.ResultsThe 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%.ConclusionsThe 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.

Keywords

• gamma energy spectrum
• noise reduction
• small wave bag
• soft threshold