| 摘要 |
<p>A seismic data acquisition unit includes a data acquisition and digitizer which receives an analog seismic signal and digitizes the signal. The data acquisition and digitizer also acquires an ambient noise signal at some point in the data acquisition and recording signal at a time when ambient noise is not masked by the seismic signal. The data acquisition unit further comprises a data compressor to receive the digitized signal from the data acquisition and digitizer and compress the digitized data, preferably with a lossy compression algorithm. Finally, the data acquisition unit comprises a data telemetry and repeater device to receive the compressed data and transmit the compressed data to a central unit. The data acquisition unit preferably includes a data decompressor. The data decompressor takes the data from the data compressor and decompresses the data. The decompressed data is then compared with the original digitized data to determine the amount of noise which resulted from the compression process. The compression noise is compared to the ambient noise, and if the compression noise exceeds a predefined criterion, then the compression ratio in the data compressor is adjusted for a lower degree of compression. The process is repeated until the amount of compression noise, relative to ambient noise, is satisfactory.</p> |
