| 摘要 |
PCT No. PCT/SE88/00585 Sec. 371 Date Jul. 23, 1990 Sec. 102(e) Date Jul. 23, 1990 PCT Filed Oct. 31, 1988 PCT Pub. No. WO89/04975 PCT Pub. Date Jun. 1, 1989.An acoustic log for vessels includes a transmitter which sends a signal within a lobe region and at least two receivers provided for receiving signals reflected from a reference for determining the velocity component of a vessel relative to the reference in the measuring direction determined by the two receivers. The log further includes a transducer device with five crystals serving as transmitter and receiver elements for transmitting and receiving acoustic signals, and being arranged such that combinations in pairs of the crystals define twelve measuring directions regularly distributed around revolution. |
