Mallat算法在数字地震信号压缩中的应用

Application of Mallat algorithm in compression of digital seismic signal

地震台站多、数据采集量大,日产出数据量庞大,研究数字地震信号的压缩方法成为行业热门课题。尝试将Mallat算法应用于数字地震波形数据压缩。选取不同的小波分解函数,对不同类型的数字地震信号进行3—5层的小波分解,将得到的小波系数进行分层硬阈值重构运算,对原始信号和处理信号进行压缩。分析可知,Mallat算法压缩比更高,与原始信号相比,重构信号不失真、能量保留系数高。

Due to such a number of seismographic observation stations, also because of high data collection capacity, daily output data in networks center is very considerable. So researching a compression method of digital seismic datas, improving the efficiency of storage format is very popular in the study of industry. This paper applies the thought of the Mallat algorithm into digital seismic waveform data compression. This article selects different functions for 3 to 5 layers of wavelet decomposition, and selectes diffenert kinds of seismic data for research. We get the details of the wavelet coefficient layered hard threshold algorithm, and then process at the original signal and the signal through wavelet transform by zip at the same time. Compared with the direct zip file of original datas, the proposed method can get a higher compression ratio, the restructure signal is no-distortion. Through this paper, we present the applicable wavelet decomposition function for compression of digital seismic waveform datas and the layer number of wavelet decomposition.