초록 ▼

A navigation system extends satellite navigation to divers. The navigation system comprises a surface unit and a plurality of sub-surface beacon units. The surface unit includes a receiver to receive navigation signals from earth-orbiting satellites, processing circuits to communicate with to sub-s

A navigation system extends satellite navigation to divers. The navigation system comprises a surface unit and a plurality of sub-surface beacon units. The surface unit includes a receiver to receive navigation signals from earth-orbiting satellites, processing circuits to communicate with to sub-surface beacon units and to transmit location information to said sub-surface beacon units, and a sonar transmitter to transmit location information to the sub-surface beacon units. The beacon units include a processing circuits to determine the location of the beacon unit based on location information received from the surface unit, and a sonar transceiver to receive location information from the surface unit while the surface unit is floating on the surface; and to transmit location information to a diver unit to provide navigation assistance to the diver unit.

대표청구항 ▼

The invention claimed is: 1. An underwater navigation system comprising: a surface unit adapted to float on the surface when deployed, said surface unit including: a receiver to receive navigation signals from earth-orbiting satellites, a sonar transceiver to communicate with to sub-surface beacon

The invention claimed is: 1. An underwater navigation system comprising: a surface unit adapted to float on the surface when deployed, said surface unit including: a receiver to receive navigation signals from earth-orbiting satellites, a sonar transceiver to communicate with to sub-surface beacon units and to transmit location information to said sub-surface beacon units; processing circuits to determine a location of the surface unit based on said navigation signals and to generate a control signal for sinking or destroying said surface unit after transmitting location information to one or more beacon units; a plurality of beacon units adapted to sink to the sea floor when deployed, each said beacon unit including: processing circuits to determine the location of the beacon unit based on location information received from the surface unit; and a sonar transceiver to receive said location information from said surface unit while the surface unit is floating on the surface; and to transmit location information to a diver unit to provide navigation assistance to the diver unit. 2. The underwater navigation system of claim 1 wherein the receiver comprises a Global Positioning System receiver. 3. The underwater navigation system of claim 1 wherein the surface unit further comprises a relay responsive to the control signal from the processing circuits for sinking or destroying the surface unit. 4. The underwater navigation system of claim 1 wherein each beacon unit determines its location based on its distance from at least one surface unit. 5. The underwater navigation system of claim 4 wherein each beacon unit determines its location by triangulation based on its distance from a plurality of surface units. 6. The underwater navigation system of claim 4 wherein each beacon unit determines its location based on its direction and distance from at least one surface unit. 7. The underwater navigation system of claim 4 wherein the beacon units determine distance from the surface unit based on the time of arrival of a signal transmitted by the surface unit. 8. The underwater navigation system of claim 4 wherein the beacon units determine distance from the surface unit based on the time of travel of a signal transmitted by the surface unit. 9. The underwater navigation system of claim 4 wherein the beacon units determine distance from the surface unit based on the received power of a dual-tone signal. 10. The underwater navigation system of claim 4 wherein the beacon units includes a plurality of sonar transducers, and wherein the processing circuits determine direction to the surface unit based on the time difference of arrival of a signal transmitted by the surface unit at said plurality of sonar transducers. 11. The underwater navigation system of claim 1 wherein the beacon units include an inactive mode and an active mode of operation. 12. The underwater navigation system of claim 11 wherein the beacon units switch from an inactive mode to an active mode of operation responsive to receipt of and activation code. 13. The underwater navigation system of claim 11 wherein the beacon units switch from an active mode to an inactive mode of operation responsive to receipt of and deactivation code. 14. The underwater navigation system of claim 11 wherein the beacon units switch from an active mode to an inactive mode of operation after a determined period has elapsed without receiving a communication. 15. A method of underwater navigation comprising: receiving navigation signals from earth-orbiting satellites by a surface unit floating on the surface of a body of water; determining location of the surface unit by an on board processing circuit in said surface unit; transmitting location information from said surface unit to a sub-surface beacon unit; and sinking or destroying said surface unit after transmitting location information to said sub-surface beacon unit. 16. The method of claim 15 further comprising: receiving location information transmitted by said surface unit at said beacon unit; and determining the location of the beacon unit based on location information received from the surface unit; transmitting location information to a diver unit to provide navigation assistance to the diver unit. 17. The method of claim 15 wherein the beacon unit determines its location based on its distance to the surface unit. 18. The method of claim 17 wherein the beacon unit determines its location based on its distance to a plurality of surface units. 19. The method of claim 17 wherein the beacon unit determines its location based on the direction and distance to the surface unit. 20. The method of claim 17 wherein the beacon unit determines distance to the surface unit based on the time of arrival of a signal transmitted by the surface unit. 21. The method of claim 17 wherein the beacon unit determines distance to the surface unit based on the time of travel of a signal transmitted by the surface unit. 22. The method of claim 17 wherein the beacon unit determines distance to the surface unit based on the received power of a dual-tone signal. 23. The method of claim 15 wherein the beacon unit determines direction to the surface unit based on the time difference of arrival of a signal transmitted by the surface unit at said plurality of sonar transducers disposed on the beacon unit. 24. The method of claim 15 wherein the beacon units switch between an inactive mode and an active mode of operation. 25. The method of claim 24 wherein the beacon unit switches from an inactive mode to an active mode of operation responsive to receipt of an activation code. 26. The method of claim 24 wherein the beacon unit switches from an active mode to an inactive mode of operation responsive to receipt of a deactivation code. 27. The method of claim 24 wherein the beacon unit switches from an active mode to an inactive mode of operation after a determined period has elapsed without receiving a communication. 28. The method of claim 16 wherein said beacon unit further uses information received from another beacon unit in addition to information received from said surface unit to determine its location. 29. The method of claim 15 wherein said surface unit calculates the location of a beacon unit and transmits the location to the beacon unit.