Underwater acoustic navigation systems and methods
First Claim
1. An underwater receiver for determining underwater locations of at least two divers, the underwater receiver comprising:
- a hydrophone configured to receive an acoustic transmission from one or more acoustic transmitters of a plurality acoustic transmitters, the plurality of acoustic transmitters forming an array having a rigid structure and configured to be suspended underwater, wherein a baseline of the array is less than and including approximately 2 meters, and wherein the one or more acoustic transmissions comprise position information of the array, attitude data of the array, and timing information;
computer hardware configured to determine, based at least in part on an absolute-time reference and the timing information, an arrival time of each of the one or more acoustic transmissions, and to use a statistical fit algorithm to determine position data of a first diver in array-fixed coordinates based at least in part on the arrival times, the position data in array-fixed coordinates determining a distance of the first diver from the array;
the computer hardware further configured to transform the position data of the first diver from the array-fixed coordinates to geodetic coordinates based at least in part on the position information of the array and the attitude data of the array;
the computer hardware further configured to determine a location of a second diver based at least in part on receipt of acoustic signals that are different from the acoustic transmissions from the one or more acoustic transmitters; and
a display to display the position data of the first diver and the location of the second diver.
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Accused Products
Abstract
An acoustic underwater navigation system is disclosed. For instance, an underwater receiver determines its position using signals broadcast from an array of acoustic transmitters located near the surface. The position of the array is measured using global positioning system (GPS) technology and the transmitters collectively produce an acoustic signal in which the position and attitude of the array and the GPS time of transmission are encoded. An underwater receiver which is synchronized with the GPS time uses the transmitted position and attitude of the array and the transmission time information to calculate its position.
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Citations
20 Claims
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1. An underwater receiver for determining underwater locations of at least two divers, the underwater receiver comprising:
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a hydrophone configured to receive an acoustic transmission from one or more acoustic transmitters of a plurality acoustic transmitters, the plurality of acoustic transmitters forming an array having a rigid structure and configured to be suspended underwater, wherein a baseline of the array is less than and including approximately 2 meters, and wherein the one or more acoustic transmissions comprise position information of the array, attitude data of the array, and timing information; computer hardware configured to determine, based at least in part on an absolute-time reference and the timing information, an arrival time of each of the one or more acoustic transmissions, and to use a statistical fit algorithm to determine position data of a first diver in array-fixed coordinates based at least in part on the arrival times, the position data in array-fixed coordinates determining a distance of the first diver from the array; the computer hardware further configured to transform the position data of the first diver from the array-fixed coordinates to geodetic coordinates based at least in part on the position information of the array and the attitude data of the array; the computer hardware further configured to determine a location of a second diver based at least in part on receipt of acoustic signals that are different from the acoustic transmissions from the one or more acoustic transmitters; and a display to display the position data of the first diver and the location of the second diver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method comprising:
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receiving underwater at a receiver an acoustic transmission from one or more acoustic transmitters of a plurality acoustic transmitters, the plurality of acoustic transmitters forming an array having a rigid structure and configured to be suspended underwater, wherein a baseline of the array is less than and including approximately 2 meters, and wherein the one or more acoustic transmissions comprise position information of the array, attitude data of the array, and timing information; determining an arrival time of each of the one or more acoustic transmissions based at least in part on an absolute-time reference and the timing information; using a statistical fit algorithm to determine position data in array-fixed coordinates based at least in part on the arrival times, the position data in array-fixed coordinates determining a distance of the first diver from the array; and transforming the position data from the array-fixed coordinates to geodetic coordinates based at least in part on the position information of the array and the attitude data of the array. - View Dependent Claims (12, 13, 14, 15)
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16. A receiver for use in an underwater navigation system, the receiver comprising:
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a hydrophone configured to receive an acoustic transmission from one or more acoustic transmitters of a plurality acoustic transmitters, the plurality of acoustic transmitters forming an array having a rigid structure and configured to be suspended underwater, wherein a baseline of the array is less than and including approximately 2 meters, and wherein the one or more acoustic transmissions comprise position information of the array, attitude data of the array, and timing information; and computer hardware configured to determine, based at least in part on an absolute-time reference and the timing information, an arrival time of each of the one or more acoustic transmissions, to use a statistical fit algorithm to determine position data in array-fixed coordinates based at least in part on the arrival times, and to transform the position data from the array-fixed coordinates to geodetic coordinates based at least in part on the position information of the array and the attitude data of the array. - View Dependent Claims (17, 18, 19, 20)
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Specification