Navigation unit and base station
The present invention relates to a navigation unit and base station used for determining location. A plurality of base stations are initialized to determine their location relative to each other. At the navigation unit, the time of arrival of at least one signal from each of the plurality of base stations is measured. From this, the location of the navigation unit relative to the plurality of base stations may be directly calculated using a closed solution. In one embodiment, a time of arrival technique is used and in another embodiment a time difference of arrival technique is used. Preferably an ultra-wide band frequency is utilized.
1. A navigation unit comprising:
a transceiver for transmitting and receiving ultra wideband signals,
a central processing unit for performing operations,
a power source for powering the transceiver and the central processing unit, and
software stored on and executed by the central processing unit for diagnosing and managing the navigation unit, and for calculating position of the navigation unit using range measurements to and between a plurality of base stations, wherein the plurality of base stations is initialized to determine their relative locations to each other in a coordinate system wherein, during initializing, a first base station of the plurality of base stations sends an ultra wideband signal to a second base station and a third base station of the plurality of base stations to determine a distance between the first base station and the second base station and a distance between the first base station and the third base station and wherein the second base station sends an ultra wideband signal to the third base station to determine a distance between the second base station and the third base station;
determining the range measurements, at the navigation unit, by measuring the time of arrival of at least one ultra wideband signal from each of the plurality of base stations;
calculating directly the location of the navigation unit relative to the plurality of base stations, where the plurality of base stations is at least three when a time of arrival technique is used and wherein the plurality of base stations is at least four when a time difference of arrival technique is used.
2. The navigation unit of claim 1 , wherein the transceiver, the central processing unit, and the power source are contained within the same housing.
3. The navigation unit of claim 1 , further comprising a global positioning system receiver for determining the location of the navigation unit.
4. The navigation unit of claim 1 , wherein the navigation unit communicates data using the ultra wideband transceiver.
5. The navigation unit of claim 4 , wherein the data contains range measurements.
6. The navigation unit of claim 1 , comprising an algorithm for determining accuracy of the navigation unit's position in relation to the plurality of base stations.
7. The navigation unit of claim 1 , wherein the power source comprises a rechargeable battery.
8. The navigation unit of claim 1 , wherein the power source comprises a wind turbine, solar panel, turbine, or generator.
9. The navigation unit of claim 1 , wherein the software program monitors power level.
10. The navigation unit of claim 1 , comprising a temperature sensor used for correcting variations in range measurement due to ambient temperature.
11. The navigation unit of claim 1 , comprising a motion sensor used for detecting if the navigation unit has moved.
12. The navigation unit of claim 1 , wherein the software program conserves power used by the navigation unit by entering the navigation unit into a low-power sleep mode.
13. The navigation unit of claim 1 , comprising a direction indicator.
14. The navigation unit of claim 1 , comprising health monitors.
15. The navigation unit of claim 1 , comprising sensors for measuring ambient conditions.
16. The navigation unit of claim 1 , using an explicit closed-form triangulation calculation to determine the location of the navigation unit.
17. The navigation unit of claim 1 , comprising a separate communication link for communicating data.
18. The navigation unit of claim 17 , wherein the separate communication link is a wireless modem.
19. The navigation unit of claim 17 , wherein the data contains range measurements.
20. The navigation unit of claim 1 , comprising a motion sensor used for measuring the movement of the navigation unit.
21. A base station comprising:
a transceiver for transmitting and receiving ultra wideband signals,
a central processing unit for performing operations,
a power source for powering the transceiver and the central processing unit, and
software stored on and executed by the central processing unit for diagnosing and managing the base station,
wherein the base station transmits range measurements to one of a plurality of base stations or one or more navigation units, wherein the plurality of base stations is initialized to determine their relative locations to each other in a coordinate system wherein, during initializing, the base station sends an ultra wideband signal to a second base station and a third base station of the plurality of base stations to determine a distance between the base station and the second base station and a distance between the base station and the third base station and wherein the second base station sends an ultra wideband signal to the third base station to determine a distance between the second base station and the third base station;
determining the range measurements, at the base station, by measuring the time of arrival of at least one ultra wideband signal from each of the plurality of base stations;
and transmitting, at the base station, the range measurement to the requesting base station or navigation unit.
22. The base station of claim 21 , wherein the transceiver, the central processing unit, and the power source are contained within the same housing.
23. The base station of claim 21 , further comprising a global positioning system receiver for determining the location of the base station.
24. The base station of claim 21 , wherein the base station communicates data using the ultra wideband transceiver.
25. The base station of claim 21 , wherein the power source comprises a rechargeable battery.
26. The base station of claim 21 , wherein the power source comprises a wind turbine, solar panel, turbine, or generator.
27. The base station of claim 21 , comprising an interface for entry of the location of the base station.
28. The base station of claim 21 , wherein the software program monitors power level.
29. The base station of claim 21 , comprising a temperature sensor used for correcting variations in range measurement due to ambient temperature.
30. The base station of claim 21 , comprising a motion sensor used for detecting if the base station has moved.
31. The base station it of claim 21 , wherein the software program conserves power used by the base station by entering the base station into a low-power sleep mode.
32. The base station of claim 21 , comprising a direction indicator.
33. The base station of claim 21 , comprising health monitors.
34. The base station of claim 21 , comprising sensors for measuring ambient conditions.
35. The base station of claim 21 , comprising a separate communication link for communicating data.
36. The base station of claim 21 , wherein the separate communication link is a wireless modem.
37. The base station of claim 21 , wherein the data contains range measurements.
38. The base station of claim 21 , comprising a motion sensor used for measuring the movement of the base station.