DUAL-SENSOR NOISE-REDUCTION SYSTEM FOR AN UNDERWATER CABLE

摘要

A system and a method for rejecting noise in an underwater sensor cable, such as a towed streamer or an ocean-bottom cable. An adaptive hydrodynamic model (22) of the cable produces an estimated sensor signal from a raw sensor signal from a particle -motion sensor, such as an accelerometer (14). The estimated sensor signal represents an estimate of the response of the underwater cable to cable motion absent seismic events. A noise - reduced response to particle motion alone is produced by subtracting (24) the estimated sensor signal from the raw sensor signal to reject cable motion and other noise effects in the raw sensor signal. A seismic event detector (18) uses a hydrophone signal from an acceleration - canceling hydrophone (10) to disable (26) the adapting of the hydrodynamic model during seismic events. The hydrophone signal is combined with the response to particle motion by PZ summation (32) to produce a deghosted seismic response signal.