GNSS regional correction data decoding

• US 10,408,941 B2
• Filed: 07/07/2017
• Issued: 09/10/2019
• Est. Priority Date: 02/14/2010
• Status: Active Grant

• Current Assignee: Trimble Inc.
• Original Assignee: Trimble Inc.
• Inventors: Chen, Xiaoming, Vollath, Ulrich, Ferguson, Kendall
• Primary Examiner(s): Gregory, Bernarr E
• Assistant Examiner(s): Mull, Fred H
• Application Number:
  US15/643,923
• Publication Number:
  US 20170307760A1
• Time in Patent Office: 795 Days
• CPC Class Codes: G01S 1/00 Beacons or beacon systems transmitting signals having a characteristic or characteristics capable of being detected by non-directional receivers and defining directions, positions, or position lines fixed relatively to the beacon transmitters; Receivers co-operating therewith position fixing by co-ordinating a plurality of determinations of direction or position lines G01S5/00
• CPC Class Codes: G01S 19/02 Details of the space or ground control segments
• CPC Class Codes: G01S 19/04 providing carrier phase data
• CPC Class Codes: G01S 19/073 involving a network of fixed stations
• CPC Class Codes: G01S 19/32 Multimode operation in a single same satellite system, e.g. GPS L1/L2
• CPC Class Codes: G01S 19/40 Correcting position, velocity or attitude
• CPC Class Codes: G01S 19/41 Differential correction, e.g. DGPS [differential GPS]
• CPC Class Codes: G01S 19/43 using carrier phase measurements, e.g. kinematic positioning; using long or short baseline interferometry
• CPC Class Codes: G01S 19/44 Carrier phase ambiguity resolution; Floating ambiguity; LAMBDA [Least-squares AMBiguity Decorrelation Adjustment] method

Abstract

A correction message for regional GNSS data includes at least one network message and at least one cluster message. The at least one network message relates to stations of a network of stations within a region. The at least one cluster message relates to a subset of stations within the region. Network elements are extracted from the network message and cluster elements are extracted from the cluster message. Network elements and cluster elements are used to determine a position of a rover within the region.

Claims

1. A method of preparing regional GNSS corrections from a correction message, the method comprising:

receiving a correction message, the correction message;

having at least one network message containing network elements relating to stations of a network of stations located within a region, wherein each network element comprises a time tag, a geometric correction for each of a multiple of satellites, and a location of a point within the region, and

having at least one cluster message with each cluster message containing cluster elements relating to a respective subset of the stations, wherein each cluster element comprises an ionospheric correction for stations in the respective subset of the stations and a location for stations in the respective subset of the stations;

extracting network elements from the at least one network message;

extracting cluster elements from the at least one cluster message; and

preparing from the network elements and the cluster elements correction data for use with rover observations to determine a position of a rover within the region.

2. The method of claim 1, wherein the correction message comprises a plurality of correction-message epochs, each correction-message epoch comprising a network message and at least one cluster message.

3. The method of claim 1, wherein the correction message of a first correction-message epoch comprises cluster messages of a first group of clusters, and the correction message of a second correction message epoch comprises cluster messages of a second group of clusters.

4. The method of claim 1, wherein at least one cluster message for each subset of the stations is included in a series of correction-message epochs.

5. The method of claim 1, wherein the network elements comprise a code bias per satellite.

6. The method of claim 5, wherein the network elements comprise a number of following cluster messages.

7. The method of claim 1, wherein the cluster elements comprise a tropospheric scaling per station.

8. The method of claim 1, wherein the correction data comprises at least one code bias per satellite, at least one of a fixed-nature Melbourne-Wü

bbena bias per satellite and values from which the fixed-nature Melbourne-Wü

bbena bias per satellite is derivable, and at least one of;

an ionospheric delay per satellite for each of multiple regional network stations, and non-ionospheric corrections.

9. The method of claim 1, wherein the correction data comprises an ionospheric delay per satellite for each of multiple regional network stations and an ionospheric phase bias per satellite.

10. The method of claim 1, wherein the network elements comprise an ionospheric phase bias per satellite and the cluster elements comprise an ionospheric delay per satellite for each of multiple regional network stations.

11. A computer program product comprising a memory device having computer-readable instructions, the computer-readable instructions when executed by a processor enabling the processor to perform the following steps:

receiving a correction message, the correction message;

having at least one network message containing network elements relating to stations of a network of stations located within a region, wherein each network element comprises a time tag, a geometric correction for each of a multiple of satellites, and a location of a point within the region, and

having at least one cluster message with each cluster message containing cluster elements relating to a respective subset of the stations, wherein each cluster element comprises an ionospheric correction for stations in the respective subset of the stations and a location for stations in the respective subset of the stations;

extracting network elements from the at least one network message;

extracting cluster elements from the at least one cluster message; and

preparing from the network elements and the cluster elements correction data for use with rover observations to determine a position of a rover within the region.

12. An apparatus comprising a processor;

and a memory device with instructions enabling the processor to prepare regional GNSS corrections from a correction message having at least one network message containing network elements relating to stations of a network of stations located within a region, and having at least one cluster message with each cluster message containing cluster elements relating to a respective subset of the stations, by;

extracting network elements from the at least one network message, wherein each network element comprises a time tag, a geometric correction for each of a multiple of satellites, and a location of a point within the region;

extracting cluster elements from the at least one cluster message, wherein each cluster element comprises an ionospheric correction for stations in the respective subset of the stations and a location for stations in the respective subset of the stations; and

preparing from the network elements and the cluster elements correction data for use with rover observations to determine a position of the rover within the region.

13. The apparatus of claim 12, wherein the correction message comprises a plurality of correction-message epochs, each correction-message epoch comprising a network message and at least one cluster message.

14. The apparatus of claim 12, wherein the correction message of a first correction-message epoch comprises cluster messages of a first group of clusters, and the correction message of a second correction message epoch comprises cluster messages of a second group of clusters.

15. The apparatus of claim 12, wherein at least one cluster message for each subset of the stations is included in a series of correction-message epochs.

16. The apparatus of claim 12, wherein the network elements comprise a code bias per satellite.

17. The apparatus of claim 16, wherein the network elements comprise a number of following cluster messages.

18. The apparatus of claim 12, wherein the cluster elements comprise a tropospheric scaling per station.

19. The apparatus of claim 12, wherein the correction data comprises at least one code bias per satellite, at least one of a fixed-nature Melbourne-Wü

bbena bias per satellite and values from which the fixed-nature Melbourne-Wü

bbena bias per satellite is derivable, and at least one of;

an ionospheric delay per satellite for each of multiple regional network stations, and non-ionospheric corrections.

20. The apparatus of claim 12, wherein the correction data comprises an ionospheric delay per satellite for each of multiple regional network stations, and an ionospheric phase bias per satellite.

21. The apparatus of claim 12, wherein the network elements comprise an ionospheric phase bias per satellite and the cluster elements comprise an ionospheric delay per satellite for each of multiple regional network stations.