Methods and apparatus having borehole seismic waveform compression

An illustrative seismic while drilling system includes a drill string having at least one seismic sensor that can be employed to detect seismic signals during pauses in the drilling process, e.g., when extending the length of the drill string. An embedded processor digitizes a signal from the seismic sensor to obtain a digital waveform and processes the digital waveform to derive a compressed waveform representation for storage or transmission. Compression is provided by adaptively reducing the sampling rate and quantization resolution subject to one or more quality constraints including, e.g., error in first break timing, error in first break sign, mean square error, and bit count. Reasonably good representations of the received acoustic waveforms can be achieved with less than 200 bits. WO 2013/052423 PCT/US2012/058330 Hydrophone or Geophone 306--, i 310--,. 31231 Analog-to-Digital Band-pass CAckst 31Sack Detector 328--, 318 316 |First-Break Distortion First-Breakk Detector Calculator Dtco Down-Sampling Anti-aliasing Filter 326-, 3243 3223 oRe-Quantizer Down-Samp Storage Memory and/or Transmitter 302--, Synchronized ,Clock Reference