Portable reference station for local differential GPS corrections

• US 20070085734A1
• Filed: 10/14/2005
• Published: 04/19/2007
• Est. Priority Date: 10/14/2005
• Status: Active Grant

• Current Assignee: Hemisphere GNSS(USA) Incorporated
• Original Assignee: CSI Wireless Incorporated
• Inventors: McClure, John, Whitehead, Michael
• Granted Patent: US 7,400,294 B2
• Time in Patent Office: Days
• US Class Current: 342/357.240
• CPC Class Codes: G01S 19/071 DGPS corrections
• CPC Class Codes: G01S 19/072 Ionosphere corrections

Abstract

A method and system for local computation of information to improve accuracy in a differential Global Navigation Satellite Systems (GNSS). The method comprising: determining a current location of a reference receiver; comparing the current location with at least one stored location; if a resultant of the comparing is less than a selected threshold, identifying as a reference location the at least one stored location, which is closest to the current location; otherwise establishing the current location as the reference location and storing the current location. The method also includes computing the information from signals from one or more GNSS satellites the based on the reference location; and transmitting the information for reception by one or more remote receivers.

Claims

1. A system for local computation of information to improve accuracy in differential Global Navigation Satellite Systems (GNSS) comprising:

a reference receiver system, said reference receiver system configured to determine a current location of said reference receiver system, said reference receiver system further configured to retrieve a stored location which is closest to said current location and comparing said current location with said one stored locations, if a resultant of said comparing is less than a selected threshold, said reference receiver identifies as a reference location said stored location, otherwise said current location is established as said reference location and stored;

said reference receiver system further configured to derive from signals from one or more GNSS satellites the information used to improve the accuracy of a remote unit based on said reference location;

at least one other receiver system, said at least one other receiver system configured as a remote unit; and

a communications link in operable communication with at least said reference receiver system and said at least one other receiver system, said communications system configured to transmit the information for reception by one or more remote receivers.

2. The system of claim 1 wherein the reference receiver system at least one of, automatically adds a new entry into said stored locations, or replaces an existing stored location with a new location, wherein said new entry is at least one of, determined using information from one or more GNSS satellites, entered by a user, or sent to the receiver over a communications link.

3. The system of claim 2 where said new entry is used as said reference location.

4. The system of claim 1 wherein the information includes at least one of:

raw satellite information, range observations, a pseudorange, positioning information, the reference location, phase data, or a plurality of differential correctors.

5. The system of claim 1 further including a rechargeable battery in operable communication with at least one of said reference receiver system and said communications link.

6. The system of claim 1 where said reference receiver system and communications link are further configured to communicate status information or an indication of status information to at least one of, one or more remote units, the battery which powers said reference receiver, or a communications link configured to facilitate said transmitting or said communicating.

7. The system of claim 6 wherein said status includes at least one of battery level, time-till-automatic-power-down, or reference receiver status.

8. The system of claim 1, wherein said reference receiver system processes information from GPS, Galileo, GLONASS, WAAS, EGNOS, MSAT or other GNSS satellites.

9. A method for local computation of information to improve accuracy in a differential Global Navigation Satellite Systems (GNSS) comprising:

determining a current location of a reference receiver;

comparing said current location with at least one stored location;

if a resultant of said comparing is less than a selected threshold, identifying as a reference location said at least one stored location, which is closest to said current location;

otherwise establishing said current location as said reference location and storing said current location;

computing the information from signals from one or more GNSS satellites the based on said reference location; and

transmitting the information for reception by one or more remote receivers.

10. The method of claim 9 further including at least one of, automatically adding a new entry into said stored locations, or replacing an existing stored location with a new location, wherein said new entry is at least one of, determined using information from one or more GNSS satellites, entered by a user, or sent to the receiver over a communications link.

11. The method of claim 10 wherein the new entry is used as said reference location for the purpose of computing differential correctors, or said transmitting.

12. The method of claim 9 wherein the information includes at least one of:

raw satellite information, range observations, a pseudorange, positioning information, the reference location, phase data, or a plurality of differential correctors.

13. The method of claim 9 further including communicating status information or an indication of status information to at least one of, one or more remote units, the battery which powers said reference receiver, or a communications link configured to facilitate said transmitting or said communicating.

14. The method of claim 13 wherein said status includes at least one of battery level, time-till-automatic-power-down, or reference receiver status.

15. The method of claim 9 where both code and carrier phase correctors or other information derived from code and carrier phase are used for the purpose of correcting a remote unit.

16. The method of claim 9, with the term “

correctors”

replace with the term “

information used to improve the accuracy of a second GPS receiver”

.

17. A system for local computation of information to improve accuracy in a differential Global Navigation Satellite Systems (GNSS) comprising:

means for determining a current location of a reference receiver;

means for comparing said current location with at least one stored location;

means for determining if a resultant of said comparing is less than a selected threshold, and means for identifying as a reference location said at least one stored location, which is closest to said current location;

otherwise, means for establishing said current location as said reference location and storing said current location;

means for computing the information from signals from one or more GNSS satellites the based on said reference location; and

means for transmitting the information for reception by one or more remote receivers.

18. A storage medium encoded with a machine-readable computer program code for local computation of information to improve accuracy in a differential Global Navigation Satellite Systems (GNSS), said storage medium including instructions for causing a computing system to implement a method comprising:

determining a current location of a reference receiver;

comparing said current location with at least one stored location;

if a resultant of said comparing is less than a selected threshold, identifying as a reference location said at least one stored location, which is closest to said current location;

otherwise establishing said current location as said reference location and storing said current location;

computing the information from signals from one or more GNSS satellites the based on said reference location; and

transmitting the information for reception by one or more remote receivers.

19. A computer data signal for local computation information to improve accuracy in a differential Global Navigation Satellite Systems (GNSS), the computer data signal comprising code configured to cause a processor to implement a method comprising:

determining a current location of a reference receiver;

comparing said current location with at least one stored location;

if a resultant of said comparing is less than a selected threshold, identifying as a reference location said at least one stored location, which is closest to said current location;

otherwise establishing said current location as said reference location and storing said current location;

computing the information from signals from one or more GNSS satellites the based on said reference location; and

transmitting the information for reception by one or more remote receivers.