Position determination using measurements from past and present epochs

1. A method comprising:

storing a first portion of information acquired from one or more sources in a first epoch, wherein said stored first portion of information includes non-pseudorange measurements for at least one of said sources and is not sufficient to compute a navigation solution; and

obtaining a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

2. The method of claim 1 , wherein said second portion of information comprises position information from at least one source among said one or more sources.

3. The method of claim 1 , wherein said second portion of information comprises a base station almanac (BSA) associated with said one or more sources.

4. The method of claim 1 , wherein said second portion of information comprises ephemeris and time information of said one or more sources.

5. The method of claim 4 , wherein said first portion of information comprises pseudorange and pseudorange rate measurements.

6. The method of claim 4 , wherein said first portion of information comprises pseudorange and carrier phase measurements.

7. The method of claim 3 , wherein said first portion of information comprises pilot phases.

8. The method of claim 3 , wherein said first portion of information comprises received signal strength indicator (RSSI).

9. The method of claim 3 , wherein said first portion of information comprises angle of arrival (AOA).

10. The method of claim 3 , wherein said first portion of information comprises pseudorange rate measurements.

11. The method of claim 3 , wherein said first portion of information comprises carrier phase measurements.

12. The method of claim 4 , further comprising:

computing pseudorange measurements based, at least in part, on said ephemeris and time information, and on said stored first portion; and

computing said navigation solution based, at least in part, on said computed pseudorange measurements and said non-pseudorange measurements.

13. The method of claim 1 , wherein said first portion of information comprises code phase detections.

14. The method of claim 1 , wherein said one or more sources comprise satellite vehicles.

15. The method of claim 1 , wherein said navigation solution comprises a position fix of a mobile receiver.

16. The method of claim 1 , further comprising

disabling pseudo-range processing for at least one of said one or more sources during said first epoch; and

enabling said pseudo-range processing for said at least one of said one or more sources subsequent to said first epoch.

17. The method of claim 1 , wherein said second portion of information comprises position information of said one or more sources that are not in view during said first epoch.

18. A method comprising:

storing a first portion of information comprising one or more measurements acquired from one or more sources in a first epoch, wherein said stored first portion of information excludes information based on received satellite positioning system (SPS) signals and is not sufficient to compute a navigation solution; and

obtaining a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

19. The method of claim 18 , wherein said second portion of information comprises a base station almanac (BSA) associated with said one or more sources.

20. The method of claim 18 , wherein said first portion of information comprises pilot phase information.

21. The method of claim 18 , wherein said first portion of information comprises angle of arrival information.

22. The method of claim 18 , wherein said first portion of information comprises received signal strength information (RSSI).

23. The method of claim 18 , wherein said first portion of information comprises pseudorange rate measurements.

24. The method of claim 18 , wherein said first portion of information comprises carrier phase measurements.

25. The method of claim 18 , wherein said first portion of information comprises inertial sensor measurements.

26. The method of claim 25 , wherein said second portion of information comprises a location fix of a past time interval.

27. The method of claim 26 , further comprising:

extrapolating forward in time to a new location based, at least in part, on said location fix of said past time interval and based, at least in part, on said inertial sensor measurements.

28. The method of claim 18 , wherein said first portion of information comprises ambiguous yaw and/or azimuth position information.

29. The method of claim 18 , wherein said one or more sources comprise one or more terrestrial transmitters.

30. The method of claim 18 , wherein said navigation solution comprises a position fix of a mobile receiver.

31. The method of claim 18 , wherein said second portion of information comprises position information of said one or more sources that are not in view during said first epoch.

32. An apparatus comprising:

a memory to store a first portion of information acquired from one or more sources in a first epoch, wherein said stored first portion of information includes non-pseudorange measurements for at least one of said sources and is not sufficient to compute a navigation solution; and

a processing unit configured to obtain a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

33. An apparatus comprising:

means for storing a first portion of information acquired from one or more sources in a first epoch, wherein said stored first portion of information includes non-pseudorange measurements for at least one of said sources and is not sufficient to compute a navigation solution; and

means for obtaining a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

34. A non-transitory computer-readable medium comprising instructions which, when executed by a processing unit, perform functions, the instructions comprising:

code to store a first portion of information acquired from one or more sources in a first epoch, wherein said stored first portion of information includes non-pseudorange measurements for at least one of said sources and is not sufficient to compute a navigation solution; and

code to obtain a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

35. An apparatus comprising:

a memory to store a first portion of information comprising one or more measurements acquired from one or more sources in a first epoch, wherein said stored first portion of information excludes information based on received satellite positioning system (SPS) signals and is not sufficient to compute a navigation solution; and

a processing unit configured to obtain a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

36. An apparatus comprising:

means for storing a first portion of information comprising one or more measurements acquired from one or more sources in a first epoch, wherein said stored first portion of information excludes information based on received satellite positioning system (SPS) signals and is not sufficient to compute a navigation solution; and

means for obtaining a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

37. A non-transitory computer-readable medium comprising instructions which, when executed by a processing unit, perform functions, the instructions comprising:

code to store a first portion of information comprising one or more measurements acquired from one or more sources in a first epoch, wherein said stored first portion of information excludes information based on received satellite positioning system (SPS) signals and is not sufficient to compute a navigation solution; and

code to obtain a second portion of information subsequent to said first epoch, enabling use of said stored first portion of information in computing said navigation solution,

wherein said obtaining is in response to a changed signal environment and/or a changed view to said one or more sources.

38. The method of claim 1 , wherein said information is based at least in part on one or more wireless signals.