Method and apparatus for processing of satellite signals without time of day information

• US 7,245,253 B2
• Filed: 03/10/2005
• Issued: 07/17/2007
• Est. Priority Date: 11/17/2000
• Status: Expired due to Term

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Global Locate Incorporated (Broadcom, Inc.)
• Inventors: Abraham, Charles, van Diggelen, Frank
• Primary Examiner(s): Issing; Gregory C.
• Application Number:
  US11/077,309
• Publication Number:
  US 20050162308A1
• Time in Patent Office: 859 Days
• Field of Search: 342/357.06, 342/357.15
• US Class Current: 342/357.62
• CPC Class Codes: G01S 19/01 Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
• CPC Class Codes: G01S 19/09 providing processing capability normally carried out by the receiver
• CPC Class Codes: G01S 19/11 wherein the cooperating elements are pseudolites or satellite radio beacon positioning system signal repeaters
• CPC Class Codes: G01S 19/235 Calibration of receiver components
• 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 19/42 Determining position
• CPC Class Codes: G01S 2205/008 using a mobile telephone network
• CPC Class Codes: G01S 5/0018 Transmission from mobile station to base station
• CPC Class Codes: G01S 5/0036 of measured values, i.e. measurement on mobile and position calculation on base station

Abstract

Method and apparatus for locating position of a satellite signal receiver is described. In one example, pseudoranges are obtained that estimate the range of a satellite signal receiver to a plurality of satellites. An absolute time and a position are computed using the pseudoranges at a first time. The absolute time is then used to compute another position at a subsequent time. In another example, a plurality of states associated with a satellite signal receiver are estimated, where the plurality of states includes a time tag error state. A dynamic model is then formed relating the plurality of states, the dynamic model operative to compute position of the satellite signal receiver.

Claims

1. A method of locating position of a satellite signal receiver, the method comprising:

obtaining pseudoranges that estimate the range of the satellite signal receiver to a plurality of satellites;

computing an absolute time and a position using the pseudoranges at a first time;

using the absolute time to compute another position at a subsequent time responsive to computing the absolute time to a predefined accuracy; and

deriving the predefined accuracy from at least one of the pseudoranges, a dilution of precision value related to the plurality of satellite signals, a signal-to-noise ratio of at least one of the plurality of satellite signals, and at least one a-posteriori pseudorange residual.

2. The method of claim 1, wherein computing an absolute time and a position comprises:

obtaining a-priori estimates of time and position; and

calculating the position and the absolute time of reception using a mathematical model that updates the a-priori estimates of time and position.

3. The method of claim 1, wherein the other position is computed using a standard global positioning system calculation, and wherein the absolute time is used as a known value in the standard global positioning system calculation.

4. The method of claim 1, wherein the other position is computed using a mathematical model that updates a-priori estimates of time and position, and wherein the absolute time is used as an additional measurement in the mathematical model.

5. The method of claim 1, further comprising:

sending the pseudoranges to a server using a wireless communication system, wherein the server computes the absolute time, the position, and the other position.

6. The method of claim 1, wherein the absolute time, the position, and the other position are computed within the satellite signal receiver.

7. The method of claim 1, wherein (i) computing an absolute time and a position, and (ii) using the absolute time to compute another position comprise:

computing a plurality of time tag errors using the pseudoranges at a respective plurality of times between the first time and the subsequent time; and

averaging the plurality of time tag errors to produce the absolute time.

8. A method of locating position of a satellite signal receiver, the method comprising:

obtaining pseudoranges that estimate the range of the satellite signal receiver to a plurality of satellites;

computing an absolute time and a position using the pseudoranges at a first time;

using the absolute time to compute another position at a subsequent time;

computing a plurality of time tag errors using the pseudoranges at a respective plurality of times between the first time and the subsequent time; and

averaging the plurality of time tag errors to produce the absolute time.

9. The method of claim 8, wherein computing an absolute time and a position comprises:

obtaining a-priori estimates of time and position; and

calculating the position and the absolute time of reception using a mathematical model that updates the a-priori estimates of time and position.

10. The method of claim 8, wherein using the absolute time to compute another position at a subsequent time occurs responsive to computing the absolute time to a predefined accuracy.

11. The method of claim 10, further comprising:

deriving the predefined accuracy from at least one of the pseudoranges, a dilution of precision value related to at least on of the plurality of satellite signals, a signal-to-noise ratio of at least one of the plurality of satellite signals, and at least one a-posteriori pseudorange residual.

12. The method of claim 8, wherein the other position is computed using a standard global positioning system calculation, and wherein the absolute time is used as a known value in the standard global positioning system calculation.

13. The method of claim 8, wherein the other position is computed using a mathematical model that updates a-priori estimates of time and position, and wherein the absolute time is used as an additional measurement in the mathematical model.

14. The method of claim 8, further comprising:

sending the pseudoranges to a server using a wireless communication system, wherein the server computes the absolute time, the position and the other position.

15. The method of claim 8, wherein the absolute time, the position, and the other position are computed within the satellite signal receiver.