Abstract: A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprises a) transmitting an optical signal into a fiber optic cable (14) that includes a sensing apparatus (20) comprising a plurality of substantially parallel fiber lengths (24), b) collecting from the sensing apparatus a plurality of received optical signals, each received signal comprising a portion of the transmitted signal that has been reflected from a different segment of a cable length, wherein the different segments are each in different cable lengths and correspond to a single selected location along the sensing cable, and c) processing the collected signals so as to obtain information about an acoustic signal received at the different segments. The cable may be ribbon cable and the lateral distance between the different segments may be less than 10 meters.

Abstract: A method for obtaining information about a subsurface formation from acoustic signals that contain information about the subsurface formation, comprises a) transmitting an optical signal into a fiber optic cable (14) that includes a sensing apparatus (20) comprising a plurality of substantially parallel fiber lengths (24), b) collecting from the sensing apparatus a plurality of received optical signals, each received signal comprising a portion of the transmitted signal that has been reflected from a different segment of a cable length, wherein the different segments are each in different cable lengths and correspond to a single selected location along the sensing cable, and c) processing the collected signals so as to obtain information about an acoustic signal received at the different segments. The cable may be ribbon cable and the lateral distance between the different segments may be less than 10 meters.