| 摘要 |
<p>A plurality of sensors (30, 32, 34), each of which is coupled to a data channel, are mounted on a downhole logging tool (18) Fig.1,(not shown) or periodically measuring and sampling, at preselected timed sample intervals, petrophysical characteristics of the borehole sidewall material. The sample values So-Sn are arranged in a two-dimensional array of a plurality of time series in channel-sequential order, indexed by consecutive sample number. Means (28) are provided for transforming (52) the plurality of time series from the time domain to the wavelet domain. The wavelet coefficients for each transformed time series are compressed (56) by thresholding. The compressed wavelet coefficients corresponding to each time series are transmitted to a receiver (35) where the compressed wavelet coefficients are decompressed (70) by formatting same into a broken sequence of wavelet coefficients. The original time series is reconstructed by inversely transforming (36) the broken sequence of wavelet coefficients from the wavelet domain back to the time domain. Information about both the selected and rejected coefficients is transmitted.</p> |
