基于小波变换的离子迁移谱信号处理技术

针对离子迁移谱信号受到噪声干扰的现状，本文提出利用小波阈值降噪的方法对离子迁移谱原始信号进行降噪处理.建立了基于小波变换的阈值降噪模型，以图谱中的1ng TNT信号为实验对象，对阈值计算原则、阈值处理方法以及小波基的选择进行了优化.结果表明：采用sym5小波，将原始信号进行3层分解后，根据固定阈值原则（Universal）获得的阈值，按照软阈值方法对小波系数进行处理并重构，原始信号中的噪声可以得到有效抑制.

Signal Processing Technology for Ion Mobility Spectrometry Based on Wavelet Transform

Aiming at the actuality that Ion Mobility Spectrometry (IMS) signal is disturbed by the noise, the wavelet threshold denoising method is developed for decreasing the original IMS signal noise. Taking 1ng TNT signals in the image as trial objects, we established a wavelet transform based denoising model by optimizing some key parameters, including threshold calculation principle, threshold processing methods, and wavelet selection. The result showed that the noise of original IMS signal was suppressed effectively according to the universal threshold selection rule after we decomposed the original signal in three layers with sym5 wavelet and processed and reconstructed the wavelet coefficients with the soft threshold method.