DETERMINING POSITIONS OF TOWED MARINE STREAMERS USING ACOUSTIC RANGING TRANSDUCERS AND GEODETIC POSITION RECEIVER ON PARAVANE

A method for determining positions of geophysical sensor streamers includes towing laterally spaced apart streamers maintained in relative relationship therebetween by paravanes 4 proximate their forward ends. The streamers include spaced apart acoustic transmitters and acoustic receivers. The paravanes each include an acoustic transmitter 9 or receiver. Signals are sent from the acoustic transmitters and are received at the acoustic receivers. Geodetic position signals are detected at each paravane, by GPS receivers 48 for example. The identities of the transmitters of the received acoustic signals are determined to determine travel times of the received acoustic signals. The travel times are converted to distances between the identified transmitters and the receivers, preferably using a measured local sound velocity of the water. Relative positions of the streamers are determined from the distances. The relative positions of the streamers are combined with the detected geodetic position signals to determine geodetic positions of the streamers. The received acoustic signals may be compensated for Doppler effects. A water movement powered electric generator (50, fig 2A) may be provided on the paravanes.