Claims
- 1. A differential positioning system for at least one mobile GPS user comprising:
a central processing facility, a plurality of reference stations with known geographic locations or positions, means for each reference station to receive GPS signals, means for each reference stations to communicate with the central processing facility, wherein the central processing facility calculates differences between the known location of the reference stations and their locations as derived from the GPS signals, means for two way communicating between the at least one mobile user and the central processing facility, and means for the mobile user to receive GPS signals, wherein the mobile user sends measurement data to the central processing facility and receives positional data therefrom.
- 2. The differential positioning system as defined in claim 1 wherein the measurement data includes pseudoranges, carrier phase, satellite Doppler, clock information, signal strength and tracking status, and the positioning data includes the corrected location of the at least one mobile user.
- 3. The differential positioning system as defined in claim 1 further comprising:
means for generating a mathematical topographical model accounting for differences between the known locations of the reference stations and the locations derived from the GPS signals, and means for processing the information received from the at least one mobile user with respect to the mathematical topographical model wherein the position of the at least one mobile user is precisely computed and sent to the at least one mobile user.
- 4. The differential positioning system as defined in claim 1 further comprising:
means for causing the reference stations to communicate with the central processing facility on a regular basis, wherein the central processing facility updates its difference calculations on the regular basis.
- 5. The differential positioning system as defined in claim 1 further comprising means for displaying the at least one mobile user's position as geographical coordinates, a moving map display, or as navigational guidance.
- 6. The differential positioning system as defined in claim 5 further comprising means for storing the calculated position history of the at least one mobile user to the at least one mobile user, and means for displaying the history at the at least one mobile user location.
- 7. The differential positioning system as defined in claim 1 further comprising a switch wherein, when the switch is set, the mobile user determines its position from its locally received GPS signals and does not use the positional data from the central processing facility.
- 8. The differential positioning system as defined in claim 1 further comprising means for the mobile user to determine its position from its locally received GPS signals
- 9. The differential positioning system as defined in claim 1 further comprising means for the mobile user to generate a local error or offset from the last corrected position received as compared to its received GPS signals and then to use this offset when the mobile user is calculating its own position from the locally received GPS signals.
- 10. A differential positioning method for at least one mobile GPS user comprising the steps of:
determining known geographic locations or positions a plurality of reference stations with, inputting the known geographical locations to a central processing facility, receiving GPS signals at each reference station, communicating between each reference stations and the central processing facility, calculating differences between the known location of the reference stations and their locations as derived from the GPS signals, two way communicating between the at least one mobile user and the central processing facility, and receiving GPS signals locally at the at least one mobile user, generating measurement data s at the at least one mobile user, sending the measurement data to the central processing facility, and receiving positional data from the central porcessing facility at the at least one mobile user.
- 11. The differential positioning method as defined in claim 10 wherein the measurement data includes pseudoranges, carrier phase, satellite Doppler, clock information, signal strength and tracking status, and the positioning data includes the corrected location of the at least one mobile user.
- 12. The differential positioning method as defined in claim 10 further comprising the steps of:
generating a mathematical topographical model accounting for differences between the known locations of the reference stations and the locations derived from the GPS signals, and processing the information received from the at least one mobile user with respect to the mathematical topographical model wherein the position of the at least one mobile user is precisely computed and sent to the at least one mobile user.
- 13. The differential positioning method as defined in claim 10 further comprising the steps of:
causing the reference stations to communicate with the central processing facility on a regular basis, wherein the central processing facility updates its difference calculations on the regular basis.
- 14. The differential positioning method as defined in claim 10 further comprising the step of displaying the at least one mobile user's position as geographical coordinates, a moving map display, or as navigational guidance.
- 15. The differential positioning method as defined in claim 14 further comprising the steps of:
storing the calculated position history of the at least one mobile user to the at least one mobile user, and displaying the history at the at least one mobile user location.
- 16. The differential positioning method as defined in claim 10 further comprising the step of determining the mobile user's position from its locally received GPS signals.
- 17. The differential positioning method as defined in claim 16 further comprising the step of selecting the locally generated position of the at least one mobile user or the correct position from the central processing facility.
- 18. The differential positioning method as defined in claim 10 further comprising the steps of generating a local error or offset at the at least one mobile user from the last corrected position received as compared to its received GPS signals, and
using the offset when the mobile user is calculating its own position from the locally received GPS signals.
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from U.S. Provisional Patent Application, of the same title as the present invention, Ser. No. 60/202,744, which was filed on May 6, 2000, by the same inventors. The provisional is hereby incorporated herein by reference.
Provisional Applications (1)
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Number |
Date |
Country |
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60202744 |
May 2000 |
US |