| 摘要 |
A well-logging method and apparatus in which a fast real time portion of a logging signal is sequentially sampled at discrete times. These sampled segments are stored and then are clocked out of storage over an expanded time period. The rms amplitude portion of the logging signal occurring prior to the compression wave part of the logging signal (the nominal noise level) may be used for AGC regulation of an amplifier which amplifies the time-expanded output. A similar development of an rms value can be used for establishing a threshold level for a peak detector, which level is set slightly higher than such rms value. The first three successive samples greater than the threshold level detected by the detector are presumed to be the first three samples of the compression wave. This presumed compression wave is recorded and convolved against the expanded-time digital form of the logging signal to locate the compression wave in a second received signal and, later, the similarly appearing "shear" wave.
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