METHOD AND SYSTEM OF IMPROVING TIME TO FIRST FIX IN A SATELLITE POSITIONING SYSTEM

• US 20070262900A1
• Filed: 05/12/2006
• Published: 11/15/2007
• Est. Priority Date: 05/12/2006
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: KLUG, KEITH, HAVERKAMP, KRISTI
• Application Number:
  US11/382,993
• Publication Number:
  US 20070262900A1
• Time in Patent Office: Days
• US Class Current: 342/357.310
• CPC Class Codes: G01S 19/28 Satellite selection
• CPC Class Codes: G01S 19/53 Determining attitude

Abstract

A satellite positioning system (SPS) antenna aiding device (100) includes an SPS receiver (102), an environmental sensor (106) to determine a heading value, a tilt value, or an acceleration value, and a processor (104). The processor can be programmed to determine (306) heading, determine (304) an estimated direction of peak antenna gain in relation to satellites in view, and prioritize (308) acquisition attempts of a portion of satellites in view based on the estimated direction of peak antenna gain and environmental data. The processor can perform (310) a split search with correlators split between searches for satellites with assumed peak gain using a shorter dwell time and longer dwell time searches for satellites with lower gain. The device can electronically present (312) an orientation guide to a user based on the estimated direction of peak antenna gain and in view of the heading of the SPS receiver.

Claims

1. A method of improving a time to first fix in a satellite positioning system (SPS), comprising the steps of:

determining a heading of an SPS device;

determining an estimated direction of peak antenna gain in relation to a plurality of satellites in view; and

prioritizing acquisition attempts of a portion of satellites in view based on the estimated direction of peak antenna gain and in view of the heading of the SPS device.

2. The method of claim 1, wherein the method further comprises the step of determining if the SPS device is in a pedestrian environment or a vehicular environment.

3. The method of claim 1, wherein the method further comprises the step of performing a split search with correlators split between searches for satellites with assumed peak gain and satellites having a lower level of gain.

4. The method of claim 3, wherein the method further comprises the steps of applying a shorter dwell time on the searches for satellite with assumed peak gain and applying a longer dwell time on the searches for satellites with the lower level of gain.

5. The method of claim 1, wherein the method further comprises the step electronically presenting an orientation guide to a user of the SPS device based on the estimated direction of peak antenna gain and in view of the heading of the SPS device.

6. The method of claim 1, wherein the step of determining the heading comprises using a magnetic compass, or a magnetic compass combined with an accelerometer to further refine the heading.

7. The method of claim 1, wherein the method further comprises the step of applying apriori known antenna gain performance values for a particular design.

8. A method of improving a time to first fix in a satellite positioning system (SPS), comprising the steps of:

retrieving GPS aiding information;

determining a set of satellites in view with approximate azimuth and elevation values;

retrieving a heading value;

determining a satellite priority-split correlation; and

performing a split correlator search based on the satellite priority-split correlation.

9. The method of claim 8, wherein the method further comprises the step of determining if a minimum number of satellites are acquired and refreshing the heading value if the split correlator search fails to find the minimum number of satellites.

10. The method of claim 8, wherein the method further comprises the step of using almanac information for the GPS aiding information.

11. The method of claim 8, wherein the method further comprises the step of using ephemeris information for the GPS aiding information.

12. The method of claim 8, wherein the heading value comprises a compass heading value.

13. The method of claim 12, wherein the heading value comprises direction of travel information and possible blockage information.

14. The method of claim 8, wherein the method further comprises the step of applying apriori known antenna gain performance values for a particular design.

15. A satellite positioning system (SPS) antenna aiding device, comprising:

an SPS receiver;

an environmental sensor to determine a heading value, a tilt value, or an acceleration value; and

a processor coupled to the SPS receiver and the environmental sensor, wherein the processor is programmed to;

determine a heading of the SPS receiver;

determine an estimated direction of peak antenna gain in relation to a plurality of satellites in view; and

prioritize acquisition attempts of a portion of satellites in view based on the estimated direction of peak antenna gain and in view of the heading of the SPS receiver.

16. The SPS antenna aiding device of claim 15, wherein the processor is further programmed to determine if the SPS receiver is in a pedestrian environment or an vehicular environment.

17. The SPS antenna aiding device of claim 15, wherein the processor is further programmed to perform a split search with correlators split between searches for satellites with assumed peak gain using a shorter dwell time and searches for satellites having a lower level of using a longer dwell time.

18. The SPS antenna aiding device of claim 15, wherein the processor is further programmed to electronically present an orientation guide to a user of the SPS antenna aiding device based on the estimated direction of peak antenna gain and in view of the heading of the SPS receiver.

19. The SPS antenna aiding device of claim 15, wherein the processor is further programmed to determine the heading using a tilt determination, a compass heading determination, or an acceleration determination to further refine the heading.

20. The SPS antenna aiding device of claim 15, wherein the processor is further programmed to apply apriori known antenna gain performance values for a particular design.