Patent ID: 7512036
Filing Date: 2009-03-31
Classification: G01S,H04B

Abstract:
1. A method for determining the position of an underwater device, comprising: providing a plurality of station keeping devices on or below the surface of the water, each station keeping device being located in a known position; providing a device to locate below the surface of the water; providing each of the station keeping devices and device to locate with a synchronized time base; providing an acoustic pulse time schedule to each of the station keeping devices and the device to locate; sending an acoustic pulse at a time according to the acoustic pulse schedule from each one of the station keeping devices, the pulse being received by the device to locate; calculating a distance between the device to locate and each station keeping device based upon the scheduled time that the acoustic pulse is sent and the time that the pulse is received; and calculating a position of the device to locate based upon the distances between the device to locate and the station keeping devices.