Systems and methods for processing navigational solutions

• US 8,190,365 B2
• Filed: 11/05/2007
• Issued: 05/29/2012
• Est. Priority Date: 11/05/2007
• Status: Active Grant

• Current Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Original Assignee: CSR Technology Incorporated (Qualcomm, Inc.)
• Inventors: Chansarkar, Mangesh, Liao, Daniel
• Primary Examiner(s): Chen, Shelley
• Application Number:
  US11/934,831
• Publication Number:
  US 20090119015A1
• Time in Patent Office: 1,667 Days
• Field of Search: 701/215
• US Class Current: 701/469
• 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 a plurality of initialization navigational measurements based on the collected navigational data, the initialization navigational measurements indicating navigational accuracy of the collected navigational data,

compute the receiver position using the initialization navigational measurements if the computed initialization navigational measurements pass a corresponding initialization threshold, and

compute the receiver position independent of the initialization navigational measurements if the computed initialization navigational measurements do not pass the corresponding initialization threshold.

2. 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.

3. 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).

4. The navigational computing device as defined in claim 3, 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.

5. 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.

6. The navigational computing device as defined in claim 5, wherein the accuracy threshold is approximately 75 kilometers.

7. The navigational computing device as defined in claim 5, 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.

8. The navigational computing device as defined in claim 7, 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.

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

collecting navigational data from at least one satellite vehicle;

computing a plurality of initialization navigational measurements based on the collected navigational data, the initialization navigational measurements indicating navigational accuracy of the collected navigational data;

computing the receiver position using the initialization navigation measurements if the computed initialization navigational measurements pass a corresponding initialization threshold; and

computing the receiver position independent of the initialization navigation measurements if the computed initialization navigational measurements do not pass the corresponding initialization threshold.

10. The method as defined in claim 9, 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.

11. The method as defined in claim 9, wherein computing the initialization navigational measurements include computing for Doppler sensitivity to position, time, clock and Dilution of Precision (DOP).

12. The method as defined in claim 11, 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.

13. The method as defined in claim 9, 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.

14. The method as defined in claim 13, further comprising configuring the accuracy threshold to be approximately 75 kilometers.

15. The method as defined in claim 13, 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.

16. The method as defined in claim 15, further comprising computing the receiver position using both the multiple solutions method and the initialization navigational measurements in real-time.

17. A navigation system comprising:

means for collecting navigational data from at least one satellite vehicle;

means for computing a plurality of initialization navigational measurements based on the collected navigation data, the initialization navigational measurements indicating navigational accuracy of the collected navigational data;

means for determining whether the computed initialization navigational measurements pass a corresponding initialization threshold;

means for computing a receiver position using the initialization navigational measurements if the initialization navigational measurements pass the corresponding initialization threshold; and

means for computing a receiver position independent of the initialization navigational measurements if the initialization navigational measurements do not pass the corresponding initialization threshold.

18. The navigation system of claim 17, wherein the initialization navigational measurements are computed using a five dimensional Doppler equation that relates position, clock and time ambiguity to the collected navigational data from at least five satellite vehicles.

19. The navigation system of claim 17, wherein the initialization navigational measurements are computed based on a Doppler sensitivity to at least one of a position, a time, a clock and a dilution of precision.

20. The navigation system of claim 17, further comprising:

means for computing a position accuracy based on the collected navigational data; and

means for determining the greater of the position accuracy and an accuracy threshold.

21. The navigation system of claim 20, wherein the means for computing a receiver position further computes a receiver position if the position accuracy is greater than the accuracy threshold.

22. The navigation system of claim 20, wherein the means for computing a receiver position further computes a receiver position using a multiple solution method if the position accuracy is less than the accuracy threshold.