Patent ID: 6985903
Filing Date: 2006-01-10
Classification: G01C,G01S,H03M,H04W

Abstract:
1. A method to retrieve elevation data, the method comprising: locating a first compressed portion of a Digital Elevation Model (DEM) using a first index, the Digital Elevation Model comprising a plurality of compressed portions which are portions of compressed profiles in a first tile of the Digital Elevation Model, the compressed portions stored in one of: a Memory Mapped File (MMF), Random Access Memory (RAM), and a file in a file system on a digital processing system, the plurality of compressed portions including the first compressed portion, the first index pointing to a storage location where the first compressed portion is stored; decompressing the first compressed portion to retrieve first elevation data for at least one sample point in the Digital Elevation Model; identifying the first tile, the first tile containing a first location and being one of a plurality of tiles in an area of the Digital Elevation Model; and identifying a first profile that is in the vicinity of the first location, the first compressed portion being a portion of the first profile.