Method and apparatus for updating transformation information parameters used in global navigation satellite system

• US 8,368,588 B2
• Filed: 10/29/2010
• Issued: 02/05/2013
• Est. Priority Date: 11/26/2007
• Status: Active Grant

• Current Assignee: MediaTek, Inc.
• Original Assignee: MediaTek, Inc.
• Inventors: Huang, Liang-Chi, Weng, Chin-Tang
• Primary Examiner(s): Phan, Dao
• Application Number:
  US12/915,006
• Publication Number:
  US 20110043404A1
• Time in Patent Office: 830 Days
• Field of Search: 342/357.23, 342/357.25, 342/357.62, 342/357.66, 701/468, 701/469
• US Class Current: 342/357.25
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver

Abstract

A method for updating a set of transformation information parameters used in a global navigation satellite system includes: obtaining at least one satellite navigation information for a satellite; and updating the set of transformation information parameters according to the obtained satellite navigation information. The method can extend the life time of the set of transformation information parameters, and used to generate better predictions of the satellite trajectory therefore the TTFF can be reduced while the positioning accuracy can also be improved.

Claims

1. A method for updating a set of transformation information parameters used in a global navigation satellite system (GNSS), comprising:

obtaining at least one satellite navigation information for a satellite; and

updating the set of transformation information parameters according to the obtained satellite navigation information;

wherein the set of transformation information parameters is used to calculate coordinate transformation between a first coordinate system and a second coordinate system, and the step of updating the set of transformation information parameters according to the obtained satellite navigation information comprises;

deriving a computed satellite data corresponding to a time point at the first coordinate system according to the obtained satellite navigation information;

generating a converted satellite data by converting a satellite data corresponding to the time point at the second coordinate system into the converted satellite data at the first coordinate system using the set of transformation information parameters; and

comparing the converted satellite data with the computed satellite data to update the set of transformation information parameters.

2. The method of claim 1, wherein the step of comparing the converted satellite data with the computed satellite data to update the set of transformation information parameters comprises:

calibrating the set of transformation information parameters by reducing a difference between the converted satellite data and the computed satellite data.

3. The method of claim 1, wherein

the step of generating the converted satellite data comprises:

computing a first computed satellite data corresponding to a first time point at the first coordinate system according to the obtained satellite navigation information;

obtaining a first converted satellite data by converting the first computed satellite data into the first converted satellite data corresponding to the first time point at the second coordinate system using the set of transformation information parameters;

estimating the satellite data at the second coordinate system according to the first converted satellite data; and

obtaining the converted satellite data by converting the satellite data into the converted satellite data at the first coordinate system using the set of transformation information parameters.

4. The method of claim 1, wherein the computed satellite data comprises a position or a velocity of the satellite at the time point, and the converted satellite data comprises a position or a velocity of the satellite at the time point transformed from the second coordinate system to the first coordinate system.

5. The method of claim 1, further comprising:

checking a validity of the set of transformation information parameters;

and the step of updating the set of transformation information parameters comprises;

when the set of transformation information parameters is not valid, updating the set of transformation information parameters according to the obtained satellite navigation information.

6. The method of claim 1, wherein the step of deriving the computed satellite data is further performed according to a first set of satellite navigation information, and the step of generating the converted satellite data is further performed according to a second set of satellite navigation information.

7. The method of claim 1, wherein Earth orientation model is considered in the first coordinate system while the Earth orientation model is not considered in the second coordinate system.

8. An apparatus for updating a set of transformation information parameters used in a global navigation satellite system, comprising:

a receiving circuit, for obtaining at least one satellite navigation information for a satellite; and

a processing circuit, coupled to the receiving circuit, for updating the set of transformation information parameters according to the obtained satellite navigation information;

wherein the set of transformation information parameters is used to calculate coordinate transformation between a first coordinate system and a second coordinate system, and the processing circuit comprises;

a calculating unit, for deriving a computed satellite data corresponding to a time point at the first coordinate system according to the obtained satellite navigation information; and

a processing unit, coupled to the calculating unit, for generating a converted satellite data by converting a satellite data corresponding to the time point at the second coordinate system into the converted satellite data at the first coordinate system using the set of transformation information parameters, and for comparing the converted satellite data with the computed satellite data to update the set of transformation information parameters.

9. The apparatus of claim 8, wherein the processing unit is arranged to calibrate the set of transformation information parameters by reducing a difference between the converted satellite data and the computed satellite data.

10. The apparatus of claim 8, wherein the processing unit is used for computing a first computed satellite data corresponding to a first time point in the first coordinate system according to the obtained satellite navigation information, obtaining a first converted satellite data by converting the first computed satellite data into the first converted satellite data corresponding to the first time point in the second coordinate system using the set of transformation information parameters, estimating the satellite data at the second coordinate system according to the first converted satellite data, and obtaining the converted satellite data by converting the satellite data into the converted satellite data at the first coordinate system using the set of transformation information parameters.

11. The apparatus of claim 8, wherein the computed satellite data comprises a position or a velocity of the satellite at the time point, and the converted satellite data comprises a position or a velocity of the satellite at the time point transformed from the second coordinate system to the first coordinate system.

12. The apparatus of claim 8, wherein the processing circuit is further arranged to check a validity of the set of transformation information parameters, and the processing circuit updates the set of transformation information parameters according to the obtained satellite navigation information when the set of transformation information parameters is not valid.

13. The apparatus of claim 8, wherein the receiving circuit is arranged to obtain a plurality of sets of different satellite navigation information for the satellite;

and the calculating unit further derives the computed satellite data according to a first set of satellite navigation information included in the sets of different satellite navigation information, and the processing unit further generates the converted satellite data according to a second set of satellite navigation information included in the sets of different satellite navigation information.

14. The apparatus of claim 8, wherein Earth orientation model is considered in the first coordinate system while the Earth orientation model is not considered in the second coordinate system.

15. The apparatus of claim 8 is installed within a global navigation satellite system receiver.

16. The apparatus of claim 8 being externally coupled to a global navigation satellite system receiver, and the processing circuit is further arranged to transmit a set of updated transformation information parameters generated from updating the set of transformation information parameters to the global navigation satellite system receiver.