Method and apparatus for position determination with hybrid SPS orbit data

• US 9,366,763 B2
• Filed: 02/04/2009
• Issued: 06/14/2016
• Est. Priority Date: 02/04/2009
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Biacs, Zoltan F., Sheynblat, Leonid, Gum, Arnold Jason
• Primary Examiner(s): McGue, Frank J
• Application Number:
  US12/365,657
• Publication Number:
  US 20100194634A1
• Time in Patent Office: 2,687 Days
• Field of Search: 342/357.06, 342/357.31, 342/357.66, 342/357.73
• US Class Current: 1/1
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/258 relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver
• CPC Class Codes: G01S 19/33 Multimode operation in different systems which transmit time stamped messages, e.g. GPS/GLONASS
• CPC Class Codes: G01S 19/42 Determining position

Abstract

A method and system for a mobile station to determine its position (or velocity) and time using a hybrid combination of satellite orbit data. In one aspect, the mobile station combines predicted orbit data from one satellite and real-time orbit data from another satellite in the determination of a fix. The combination can be made to the satellites in the same or different satellite systems. The mobile station can use the real-time orbit data of a satellite at one time period and the predicted orbit data of the same satellite at another time period. In another aspect, the mobile station can use the real-time orbit data to correct the clock bias in the predicted orbit data. The correction to the clock bias can be made to the same satellite that provides the real-time orbit data, or to a different satellite in the same or in another satellite system.

Claims

1. A system implemented in a mobile station, the system comprising:

a receiver interface configured to receive real-time orbit data of a first satellite;

a correction unit configured to identify at least one real-time clock parameter within the real-time orbit data and to correct an error of a clock bias in predicted orbit data of one or more additional satellites using the at least one real-time clock parameter within the real-time orbit data of the first satellite; and

a combining unit configured to combine the real-time orbit data of the first satellite with predicted orbit data, comprising corrected clock bias data that was corrected using the at least one real time clock parameter within the real-time orbit data of the first satellite, of a second satellite in determination of spatial and time information of the mobile station, wherein the first satellite and the second satellite belong to two different satellite systems, and wherein the predicted orbit data has an extended period of validity compared to the real-time orbit data and comprises at least one of 3-D uncertainty values for predicted satellite coordinates or uncertainty values of predicted satellite clock corrections.

2. The system of claim 1, wherein:

the receiver interface is further configured to;

receive predicted orbit data from each of a plurality of satellites; and

receive real-time orbit data from each of the plurality of satellites; and

the combining unit is further configured to determine whether the mobile station has received predicted orbit data and real-time orbit data from each of the plurality of satellites sufficient to constitute an over-determined system for determining a position fix of the mobile station.

3. The system of claim 2, wherein if it is determined there is an over-determined system, the combining unit is further configured to:

assign weighing components to each of the predicted orbit data and the real-time orbit data from each of the plurality of satellites, the weighing components based according to an accuracy criteria for each of the predicted orbit data and the real-time orbit data; and

determine the position fix of the mobile station by combining the predicted orbit data and the real-time orbit data from each of the plurality of satellites in a combination according to the weighing components assigned.

4. The system of claim 3, wherein the combining unit is further configured to:

weigh predicted orbit data and real-time orbit data that have smaller errors more heavily than predicted orbit data and real-time orbit data that have larger errors;

weigh predicted orbit data and real-time orbit data that are more recent more heavily than predicted orbit data and real-time orbit data that are less recent;

weigh predicted orbit data and real-time orbit data that have a higher User Range Accuracy (URA) more heavily than predicted orbit data and real-time orbit data that have a lower URA; and

weigh predicted orbit data and real-time orbit data that have a lower User Range Error (URE) more heavily than predicted orbit data and real-time orbit data that have a higher URE.

5. The system of claim 1, wherein the combining unit configured to combine the real-time orbit data of the first satellite with the predicted orbit data of the second satellite is configured to:

use a weighted combination to combine the real-time orbit data of the first satellite with the predicted orbit data of the second satellite according to;

Orbit_combined=(W₁×

O_real-time+W₂×

O_predicted)/(W₁+W₂),

where O_real-time is the real-time orbit data for the first satellite, O_predicted is the predicted orbit data for the second data, and W₁ and W₂ are weight values derived as functions of User Range Accuracy (URA), User Range Error (URE), time to Time of Ephemeris (TOE), and an age of the predicted orbit data since a last update.

6. The system of claim 1, wherein the correction unit configured to correct the error of the clock bias in the predicted orbit data of the one or more additional satellites is configured to:

correct the error of the clock bias data in the predicted orbit data of the second satellite using the real-time orbit data for the first satellite with real-time data from one or more additional satellites within a first satellite system including the first satellite, with a number of satellites within the first satellite system providing the real-time data to the mobile station being sufficient to determine a position fix for the mobile station.

7. A system implemented by a mobile station, the system comprising:

a receiver interface configured to receive real-time orbit data from a plurality of first satellites for a determination of spatial and time information of the mobile station;

a correction unit configured to identify at least one real-time clock parameter within the real-time orbit data and to correct an error of a clock bias in predicted orbit data of one or more second satellites using the at least one real-time clock parameter within the real-time orbit data of the plurality of first satellites, wherein each of the plurality of first satellites are different from each of the one or more second satellites; and

a combining unit configured to combine the real-time orbit data from the plurality of first satellites with the predicted orbit data, comprising corrected clock bias data that was corrected using the at least one real time clock parameter within the real-time orbit data of the plurality of first satellites, of the one or more second satellites in determination of spatial and time information of the mobile station;

wherein a number of satellites in the plurality of first satellites is equal to or greater than a number of unknowns in the spatial and time information of the mobile station.

8. The system of claim 7, wherein respective ones of the plurality of first satellites belong to different satellite systems.

9. The system of claim 7, wherein each of the plurality of first satellites belong to a first satellite system and the one or more second satellites belong to one or more other satellite systems.

10. The system of claim 7, wherein the correction unit is further configured to use the real-time orbit data of a first one of the plurality of first satellites to correct the error of the clock bias in predicted orbit data of a first one of the plurality of first satellites.

11. A mobile station, comprising:

means for receiving real-time orbit data of a first satellite;

means for identifying at least one real-time clock parameter within the real-time orbit data;

means for correcting an error of a clock bias in predicted orbit data of one or more additional satellites using the at least one real-time clock parameter within the real-time orbit data of the first satellite; and

means for combining the real-time orbit data of the first satellite and predicted orbit data, comprising corrected clock bias data that was corrected using the at least one real time clock parameter within the real-time orbit data of the first satellite, of a second satellite in determination of spatial and time information of the mobile station, wherein the first satellite and the second satellite belong to two different satellite systems, and wherein the predicted orbit data has an extended period of validity compared to the real-time orbit data and comprises at least one of 3-D uncertainty values for predicted satellite coordinates or uncertainty values of predicted satellite clock corrections.

12. A computer program product for enabling a computer to determine spatial and time information, the computer program product comprising:

software instructions for enabling the computer to perform predetermined operations comprising generating spatial and time information of a mobile station; and

a non-transitory computer readable storage medium bearing the software instructions;

the predetermined operations further comprising;

receiving information indicative of real-time orbit data of a first satellite from a first satellite system;

identifying at least one real-time clock parameter within the real-time orbit data of the first satellite;

correcting an error of a clock bias in predicted orbit data of one or more additional satellites using the at least one real-time clock parameter within the real-time orbit data of the first satellite; and

receiving information indicative of a combination of the real-time orbit data of the first satellite and predicted orbit data, comprising corrected clock bias data that was corrected using the at least one real time clock parameter within the real-time orbit data of the first satellite, of a second satellite from a second satellite system, wherein the second satellite system is different from the first satellite system, and wherein the predicted orbit data has an extended period of validity compared to the real-time orbit data and comprises at least one of 3-D uncertainty values for predicted satellite coordinates or uncertainty values of predicted satellite clock corrections.

13. A method comprising:

receiving at a mobile station real-time orbit data of a first satellite;

identifying at the mobile station at least one real-time clock parameter within the real-time orbit data;

correcting at the mobile station an error of a clock bias in predicted orbit data of one or more additional satellites using the at least one real-time clock parameter within the real-time orbit data of the first satellite; and

combining at the mobile station the real-time orbit data of the first satellite and predicted orbit data, comprising corrected clock bias data that was corrected using the at least one real time clock parameter within the real-time orbit data of the first satellite, of a second satellite in determination of spatial and time information of the mobile station, wherein the first satellite and the second satellite belong to two different satellite systems, and wherein the predicted orbit data has an extended period of validity compared to the real-time orbit data and comprises at least one of 3-D uncertainty values for predicted satellite coordinates or uncertainty values of predicted satellite clock corrections.

14. The method of claim 13, wherein combining the real-time orbit data of the first satellite with the predicted orbit data of the second satellite comprises:

using a weighted combination to combine the real-time orbit data of the first satellite with the predicted orbit data of the second satellite according to;

Orbit_combined=(W₁×

O_real-time+W₂×

O_predicted)/(W₁+W₂),

where O_real-time is the real-time orbit data for the first satellite, O_predicted is the predicted orbit data for the second data, and W₁ and W₂ are weight values derived as functions of User Range Accuracy (URA), User Range Error (URE), time to Time of Ephemeris (TOE), and an age of the predicted orbit data since a last update.

15. The method of claim 13, wherein correcting the error of the clock bias in the predicted orbit data of the one or more additional satellites comprises:

correcting the error of the clock bias data in the predicted orbit data of the second satellite using the real-time orbit data for the first satellite with real-time data from one or more additional satellites within a first satellite system including the first satellite, with a number of satellites within the first satellite system providing the real-time data to the mobile station being sufficient to determine a position fix for the mobile station.