Systems and Methods for Processing Navigational Solutions

• US 20090119015A1
• Filed: 11/05/2007
• Published: 05/07/2009
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: SIRF Technology Incorporated (Qualcomm, Inc.)
• Inventors: Chansarkar, Mangesh, Liao, Daniel
• Granted Patent: US 8,190,365 B2
• Time in Patent Office: Days
• US Class Current: 701/215
• CPC Class Codes: G01S 19/42 Determining position

Abstract

Systems and methods for processing navigational solutions are provided. In this regard, a representative system includes a navigational computing device comprising a processor and memory that stores a navigational solution manager that is executed by the processor to provide a receiver position. The navigational solution manager is configured to collect navigational data from at least one satellite vehicle, compute initialization navigational measurements based on the collected navigational data, and compute the receiver position using the initialization navigation measurements.

Claims

1. A navigational computing device comprising:

a processor; and

memory that stores a navigational solution manager that is executed by the processor to provide a receiver position, the navigational solution manager being configured to;

collect navigational data from at least one satellite vehicle,

compute initialization navigational measurements based on the collected navigational data, and

compute the receiver position based on the initialization navigational measurements.

2. The navigational computing device as defined in claim 1, wherein the navigational solution manager is further configured to:

determine whether the initialization navigation measurements pass initialization thresholds, and

responsive to the initialization navigation measurements passing the initialization thresholds, compute the receiver position based on the initialization navigation measurements.

3. The navigational computing device as defined in claim 1, wherein the computation of the initialization navigational measurements includes a five (5) dimensional Doppler equation that relates position, clock and time ambiguity to the collected Doppler measurements from at least five (5) satellite vehicles.

4. The navigational computing device as defined in claim 1, wherein the initialization navigational measurements include Doppler sensitivity to position, time, clock and Dilution of Precision (DOP).

5. The navigational computing device as defined in claim 4, wherein if the Doppler sensitivity to position, time, and DOP are approximately 1 Hz per Km, approximately 10 Hz and approximately 4, respectively, then the receiver position is computed to have an accuracy of approximately 40 Km.

6. The navigational computing device as defined in claim 1, wherein the navigational solution manager is further configured to:

compute a position accuracy value based on the collected navigational data,

determine whether the position accuracy value is greater than an accuracy threshold, and

responsive to the position accuracy value being greater than the accuracy threshold, compute the receiver position based on the initialization navigation measurements.

7. The navigational computing device as defined in claim 6, wherein the accuracy threshold is approximately 75 kilometers.

8. The navigational computing device as defined in claim 6, wherein the navigational solution manager being further configured to, responsive to the position accuracy value being less than the accuracy threshold, compute the receiver position using a multiple solutions method, the multiple solutions method being derived from multiple integer millisecond hypotheses and having approximately 32 position computations.

9. The navigational computing device as defined in claim 8, wherein the navigational solution manager being further configured to compute the receiver position using both the multiple solutions method and the initialization navigational measurements in real-time.

10. A method for computing a navigational solution, comprising the steps of:

collecting navigational data from at least one satellite vehicle;

computing initialization navigational measurements based on the collected navigational data; and

computing the receiver position using the initialization navigation measurements.

11. The method as defined in claim 10, further comprising:

determining whether the initialization navigational measurements pass initialization thresholds, and

responsive to the initialization navigation measurements passing the initialization thresholds, computing the receiver position based on the initialization navigation measurements.

12. The method as defined in claim 10, wherein computing the initialization navigational measurements includes using a five (5) dimensional Doppler equation that relates position, clock and time ambiguity to the collected Doppler measurements from at least five (5) satellite vehicles.

13. The method as defined in claim 10, wherein computing the initialization navigational measurements include computing for Doppler sensitivity to position, time, clock and Dilution of Precision (DOP).

14. The method as defined in claim 13, further comprising, if the Doppler sensitivity to position, the time, and the DOP are approximately 1 Hz per Km, approximately 10 Hz, and approximately 4, respectively, then computing the receiver position to have an accuracy of approximately 40 Km.

15. The method as defined in claim 10, further comprising:

computing a position accuracy value based on the collected navigational data;

determining whether the position accuracy value is greater than an accuracy threshold; and

responsive to the position accuracy value being greater than the accuracy threshold, computing the receiver position using the initialization navigation measurements.

16. The method as defined in claim 15, further comprising configuring the accuracy threshold to be approximately 75 kilometers.

17. The method as defined in claim 15, further comprising, responsive to the position accuracy value being less than the accuracy threshold, computing the receiver position using a multiple solutions method, the multiple solutions method being derived from multiple integer millisecond hypotheses and having approximately 32 position computations.

18. The method as defined in claim 17, further comprising computing the receiver position using both the multiple solutions method and the initialization navigational measurements in real-time.

19. A navigation receiver comprising:

receiving means for receiving data from a satellite; and

a navigational computing device that includes;

a processor;

memory that stores a navigational solution manager this is executed by the processor to provide a receiver position, the navigational solution manager being configured to;

collect navigational data from at least one satellite vehicle,

compute initialization navigational measurements based on the collected navigational data,

compute a position accuracy value based on the collected navigational data,

determine whether the position accuracy value is greater than an accuracy threshold,

responsive to the position accuracy value being greater than the accuracy threshold, compute the receiver position using the initialization navigation measurements, and

responsive to the position accuracy value being less than the accuracy threshold, compute the receiver position using a multiple solutions method, the multiple solutions method being derived from multiple integer millisecond hypotheses and having approximately 32 position computations.

20. The navigation receiver as defined in claim 19, wherein the navigational solution manager is further configured to:

determine whether the initialization navigation measurements pass initialization thresholds, and

responsive to the initialization navigation measurements passing the initialization thresholds, compute the receiver position based on the initialization navigation measurements.