METHOD AND APPARATUS FOR GENERATING AND USING A REGIONAL-TERRAIN MODEL

• US 20090066576A1
• Filed: 03/21/2006
• Published: 03/12/2009
• Est. Priority Date: 03/21/2006
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Global Locate Incorporated (Broadcom, Inc.)
• Inventors: van Diggelen, Frank
• Granted Patent: US 7,739,032 B2
• Time in Patent Office: Days
• US Class Current: 342/357.270
• CPC Class Codes: G01S 19/50 whereby the position solution is constrained to lie upon a particular curve or surface, e.g. for locomotives on railway tracks

Abstract

A method and apparatus for computing position using a regional-terrain model is provided. The method includes obtaining from at least three satellites pseudorange measurements, computing a transitional position by using a default altitude with a large uncertainty, using this transitional position to obtain from a terrain model altitude information associated with a region, and computing an accurate three-dimensional position as a function of the pseudorange measurements and the altitude information. The region defines a boundary, and the boundary includes the transitional position.

Claims

1-8. -8. (canceled)

9. An apparatus for computing position, comprising:

a receiver operable to obtain pseudorange measurements at a location;

a terrain module operable to contain a regional-terrain model, the regional-terrain model including altitude information associated with a moderated region, wherein the modeled region defines its boundary as a function of a range of altitudes, and wherein the location is within boundary; and

a processor operable to perform logic to;

obtain from the regional-terrain model the altitude information, and

compute a position of the location as a function of the pseudorange measurements and the altitude information.

10. The apparatus of claim 9, wherein the altitude information comprises an altitude and an altitude uncertainty.

11. The apparatus of claim 10, wherein the altitude comprises a first altitude from a given reference point associated with the earth, and the altitude uncertainty comprises a given deviation from the first altitude.

12. The apparatus of claim 9, wherein the boundary is defined by an interconnection of a number of coordinate-system points that together delineate the modeled region.

14. The apparatus of claim 12, wherein the boundary is defined by a point and a line segment.

15. The apparatus of claim 12, wherein the altitude information is used when a speed of the receiver is less than a threshold value.

23. The apparatus of claim 9, wherein the boundary is a function of the range of altitudes of the terrain.

13. (canceled)

16-22. -22. (canceled)