A seismic data acquisition unit includes a data acquisition and digital circuit which receives an analog seismic signal and digitizes the signal. The digitized seismic data uses data telemetry and a repeater device to receive the compressed data and transmit the compressed data to a seismic central control unit. 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 resulting 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.