| 摘要 |
A apparatus for detecting an underwater electrically conductive device (70, figure 2), which optionally can be a cable or pipeline, by measuring a first received magnetic field using a target detection receiver (130, figure 3A) with a first detection range and measuring a second received magnetic field using a seawater detection receiver (110, figure 3A) with a second detection range. The transmitters are separate from the receivers. Optionally, the seawater response is calculated from the seawater detection receiver, and this response is subtracted S2 from the target response, which is a combination of the pipeline and seawater response. Optionally, the detection apparatus is located on an underwater vehicle (10, figure 2). Optionally the second detection range is smaller than that of the first detection range. Optionally, the receivers can use either an induction coil, magnetometer or hall-effect device. |
