Techniques for geophysical data compression

摘要

Lossless compression is never as profitable, in terms of compression ratio, as lossy compression of the same data. However, lossless techniques that produce significant compression of geophysical waveform data are possible. A two-stage technique for lossless compression of geophysical waveform data is described. The first and most important stage is a form of linear prediction that allows exact recovery of the original waveform data from the predictor residue sequence. The second stage is an encoder of the first-stage residue sequence which approximately maximizes the entropy of the latter, while allowing exact recovery during decompression. We review the overall two-stage technique, which has been described previously, and concentrate in this paper on some recent performance examples and results using the technique. To obtain the latter, a seismic waveform data base is introduced and made available. We conclude that lossless compression of seismic data can save significant amounts of storage in seismic data bases and archives, and significant amounts of bandwidth in real-time communication of instrumentation data.