Method and apparatus for generating and using a regional-terrain model
AssigneeGlobal Locate, Inc.
InventorFrank Van Diggelen
Life of this patent
Estimating the term…
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.
Claims17
A method for computing position in a receiver, comprising:
- obtaining pseudorange measurements at a location, with a circuit of the receiver;
- determining a speed of the receiver;
- comparing the speed of the receiver to a threshold value;
- and
- if the speed of the receiver is below the threshold value,
- obtaining from a regional-terrain model altitude information associated with a modeled region, wherein the location is in a vicinity of the modeled region;
- and
- computing a position as a function of the pseudorange measurements and the altitude information,
- wherein obtaining from a regional-terrain model altitude information comprises obtaining from the regional-terrain model an altitude and an altitude uncertainty.
A method for forming a regional terrain model, the method comprising:
- defining at least one modeled region of the regional terrain model as a function of a boundary formed using a first altitude at a first location and at least a second altitude at a second location, wherein the first altitude and the second altitude are within a range of altitudes, including:
- obtaining from a point-based terrain model the first altitude at the first location;
- locating in the point-based terrain model an additional location, wherein the additional location is spaced apart from the first location;
- obtaining from the point-based terrain model an additional altitude associated with the additional location;
- excluding from the boundary the additional location when the additional altitude is not within the range of altitudes;
- and
- including in the boundary the additional location as the second location when the additional altitude is within the range of altitudes;
- and
- storing the modeled region in the regional terrain model in a memory.
A method for computing a position of a receiver, comprising:
- computing a transitional position of the receiver with a circuit;
- determining a speed of the receiver;
- comparing the speed of the receiver to a threshold value;
- and
- if the speed of the receiver is below the threshold value,
- obtaining from a regional-terrain model altitude information associated with a modeled region, wherein the transitional position is in a vicinity of the modeled region;
- and
- computing the position of the receiver as a function of the altitude information.
A method for forming a regional-terrain model, the method comprising:
- collecting, at a mobile receiver, a plurality of altitudes associated with a respective plurality of positions of the mobile receiver;
- defining, by the mobile receiver, at least one modeled region using the plurality of altitudes, wherein the modeled region is associated with an altitude and altitude uncertainty;
- and
- storing the modeled region in the regional-terrain model at the mobile receiver.
A receiver, comprising:
- a memory configured to store a regional-terrain model;
- a module configured to determine a speed of the receiver and to compare the speed of the receiver to a threshold value;
- and
- a positioning module configured to obtain pseudorange measurements associated with a location of the receiver, the positioning module further configured, if the speed of the receiver is below the threshold value, to obtain from the regional-terrain model altitude information associated with a modeled region, wherein the location of the receiver is in a vicinity of the modeled region, and to compute a position of the receiver as a function of the pseudorange measurements and the altitude information.
Dependencies are inferred from the claim text.