| 摘要 |
<p>A method and apparatus for underwater ranging with the aid of sonic pulses, by irradiating a given transmitting area with sonic energy pulses from a transmitter mounted in a marine vessel, receiving sonic energy echoes reflected from bodies in the transmitting area in a manner which is selective with respect to direction in a plurality of receiving sectors arranged in a fan shape, and associating the received echoes with respective reflection centers within the respective receiving sectors on the basis of associated sonic pulse travel times. Reception is carried out on a second marine vessel different from the vessel carrying the transmitter and which travels at a rearward offset position from the vessel carrying the transmitter at such a distance therefrom that the receiving sectors cover at least part of the given transmitting area, and the azimuthal width of the transmitting area is made very small. The associating operation includes determining the relative distance between the two vessels and the direction of the transmitting area, relative to the heading of the second vessel, at least at the moment of transmission of each sonic pulse, in order to associate the reflection centers with the echoes.</p> |
