SHIP MOUNTED UNDERWATER SONAR SYSTEM
1 Assignment
0 Petitions
Accused Products
Abstract
A process and apparatus for detecting underwater objects comprises an elongate array of ultrasound transmitter elements mounted substantially vertically and forward facing on the bow of the ship from which is transmitted a sequence of ultrasound wave pulses, with each pulse having a frequency and vertical beam angle which are different to the frequency and vertical beam angle of the preceding pulse in the sequence, the frequency being characteristic of the vertical beam angle and the vertical beam angle being controlled by using time delays between different transmitter elements, and an elongate array of ultrasound receiver elements mounted substantially horizontally on the bow of said ship with the receiver elements forward facing which receive any ultrasound waves reflected from objects in front of the ship, the output from the receiver elements being steered horizontally using time delays between different receiver element outputs and for each horizontal position of the beam of outputs, the outputs from the receiver elements having those time delays associated with that horizontal position of the beam of outputs are summed in a beamformer.
-
Citations
36 Claims
-
1-11. -11. (canceled)
-
12. A process for detecting underwater objects comprising:
-
(a) providing a ship with an underwater sonar system comprising an elongate array of ultrasound transmitter elements and an elongate array of ultrasound receiver elements in which the array of transmitter elements is mounted substantially vertically and forward facing on the bow of the ship such that in use, the transmitter elements transmit ultrasound wave pulses in a beam in the direction of travel of the ship, and the array of receiver elements is mounted substantially horizontally on the bow of said ship with the receiver elements forward facing to receive any ultrasound waves reflected from objects in front of the ship; (b) transmitting from the transmitter elements, a sequence of ultrasound wave pulses, with each pulse having a frequency and vertical beam angle which are different to the frequency and vertical beam angle of the preceding pulse in the sequence, the frequency being characteristic of the vertical beam angle and the vertical beam angle being controlled by using time delays between the ultrasound waves transmitted by different transmitter elements; (c) receiving with the receiver elements, any ultrasound waves reflected from objects in front of the ship;
horizontally steering a beam of outputs from the receiver elements by using time delays between different receiver element outputs; and
for each horizontal position of the beam of outputs, summing in a beamformer, the outputs from the receiver elements having those time delays associated with that horizontal position of the beam of outputs; and(d) determining the 3-dimensional coordinates of any objects in front of the ship from the summed outputs from the receiver elements. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 35, 36)
-
-
34. A ship having an underwater sonar system comprising an elongate array of ultrasound transmitter elements and an elongate array of ultrasound receiver elements characterised in that:
(i) the array of transmitter elements is mounted substantially vertically and forward facing on the bow of the ship and is adapted such that in use, the transmitter elements transmit a sequence of ultrasound wave pulses, each pulse being in a beam in the direction of travel of the ship, with each pulse having a frequency and vertical beam angle which are different to the frequency and vertical beam angle of the preceding pulse in the sequence, the frequency being characteristic of the vertical beam angle and the vertical beam angle being controlled by using time delays between the ultrasound waves transmitted by different transmitter elements, and (ii) the array of receiver elements is mounted substantially horizontally on the bow of said ship with the receiver elements forward facing to receive any ultrasound waves reflected from objects in front of the ship, and is adapted such that in use, a beam of outputs from the receiver elements is steered horizontally by using time delays between different receiver element outputs and for each horizontal position of the beam of outputs, the outputs from the receiver elements having those time delays associated with that horizontal position of the beam of outputs are summed in a beamformer.
Specification