| 摘要 |
<p>A system for the detection of leakages from subsea installations, particularly from high-pressure pipelines used for the transport of gas. One or preferably more sonar receivers (15) are located at a considerable distance from a transmitter (14) in order to increase the detection certainty. The system preferably incorporates a circuit for the cross-correlation of the different signals which are received with the transmitted signal in order to detect any frequency changes and thereby determine the velocity and direction of movement of the reflecting objects. It is an advantage that a number of receivers (15) are alternately positioned in rows on either side of a pipeline (13) or similar structure.</p> |
