Offshore marine seismic source tow systems and methods of forming

Abstract

Two modifications of an offshore marine seismic energy source tow system are disclosed. Both systems comprise transmitters and receivers therein for continuously measuring the distance between a vessel towed submerged geophone streamer cable and a towed seismic air gun supporting paravane on each side of the streamer cable for generating and transmitting corrective steering signals to the paravane for maintaining each seismic air gun spaced from the towed submerged geophones at an exact predetermined distance for producing more accurate seismic velocity measurements. One embodiment has the acoustic transmitter on the geophone streamer cable and an acoustic receiver on each paravane in line with the transmitter, and a second embodiment has an acoustic transmitter on each paravane and a corresponding acoustic receiver for each paravane on the geophone streamer cable transversely of the transmitter. Methods for assembling the above two systems are disclosed.