Method and apparatus of using height aiding from a contour table for GNSS positioning
First Claim
1. A method for determining a position of a GPS receiver, the method comprising:
- at the GPS receiver;
computing a coarse estimate of an absolute position of the GPS receiver using GNSS signals;
retrieving height information stored in a contour table associated with the GPS receiver using the coarse estimate; and
computing a final estimate of the absolute position of the GPS receiver by using the retrieved height information and the GNSS signals.
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Abstract
The present invention is related to location positioning systems, and more particularly, to a method and apparatus for making accuracy improvements to a GPS receiver'"'"'s navigation calculations. According to a first aspect, the invention includes maintaining a table of height attributes for major cities and urban areas around the world (contour table) in the GNSS chipset. The information in the table preferably includes latitude, longitude of the city along with height attributes of those cities, such as the average, min, max height and region boundary etc. Additional information such as average gradient could also be saved in the table. According to further aspects, when GPS signals are degraded in environments such as urban canyons, the height information can be obtained from the table and used to improve the navigation solution.
39 Citations
21 Claims
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1. A method for determining a position of a GPS receiver, the method comprising:
at the GPS receiver; computing a coarse estimate of an absolute position of the GPS receiver using GNSS signals; retrieving height information stored in a contour table associated with the GPS receiver using the coarse estimate; and computing a final estimate of the absolute position of the GPS receiver by using the retrieved height information and the GNSS signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 18, 21)
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9. A method for determining a position of a GPS receiver, the method comprising:
at the GPS receiver; retrieving height information stored in a contour table associated with the GPS receiver; and computing a position fix of the GPS receiver by using the retrieved height information, wherein retrieving height information includes; computing a coarse position; comparing the coarse position with entries in the contour table, each entry comprising height information for a corresponding location, wherein comparing a position associated with one of the entries to determine whether it is within a predetermined distance of the coarse position, wherein the predetermined distance is adjusted based on a height of the coarse position; and finding one or more matching entries in the contour table.
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19. A device, comprising:
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a contour table; and a GPS receiver coupled to the contour table, the GPS receiver including a processor that is programmed to perform a method comprising; computing a coarse estimate of an absolute position of the GPS receiver using GNSS signals; retrieving height information stored in a contour table associated with the GPS receiver using the coarse estimate; and computing a final estimate of the absolute position of the GPS receiver by using the retrieved height information and the GNSS signals. - View Dependent Claims (20)
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Specification