Method and apparatus for providing a tile-based digital elevation model

An apparatus for providing a digital elevation model comprising:

• at least one processor;
• and
• at least one memory including computer program code for one or more programs,
• the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following,
• process map elevation data to create a hierarchical resolution tile representation of the digital elevation model for a geographic area,
• wherein the hierarchical resolution tile representation includes a plurality of resolution levels, each of the plurality of levels representing the digital elevation model at a different resolution,
• wherein the digital elevation model includes a plurality of control points, each of the plurality of control points being associated with an elevation data point determined from the map elevation data;
• for a tile at one level of the plurality of resolution levels, create a local digital elevation model by projecting the map elevation data for the tile to a tangent plane comprising a plurality of elevation data points;
• compute a probability map for the plurality of elevation data points, the probability map indicating respective probability data that each of the plurality of elevation data points is associated with a corresponding elevation value;
• and
• create a new local digital elevation model based on the probability map.

A non-transitory computer-readable storage medium for providing a digital elevation model, and carrying one or more sequences of one or more instructions which, when executed by one or more processors, cause an apparatus to perform:

• processing map elevation data to create a hierarchical resolution tile representation of the digital elevation model for a geographic area,
• wherein the hierarchical resolution tile representation includes a plurality of resolution levels, each of the plurality of levels representing the digital elevation model at a different resolution,
• wherein the digital elevation model includes a plurality of control points, each of the plurality of control points being associated with an elevation data point determined from the map elevation data;
• for a tile at one level of the plurality of resolution levels, creating a local digital elevation model by projecting the map elevation data for the tile to a tangent plane comprising a plurality of elevation data points;
• computing a probability map for the plurality of elevation data points, the probability map indicating respective probability data that each of the plurality of elevation data points is associated with a corresponding elevation value;
• and
• creating a new local digital elevation model based on the probability map.

A method for providing a digital elevation model comprising:

• processing, by a processor, map elevation data to create a hierarchical resolution tile representation of the digital elevation model for a geographic area,
• wherein the hierarchical resolution tile representation includes a plurality of resolution levels, each of the plurality of levels representing the digital elevation model at a different resolution;
• wherein the digital elevation model includes a plurality of control points, each of the plurality of control points being associated with an elevation data point determined from the map elevation data,
• wherein the map elevation data for said each of the plurality of resolution levels is retrieved from a plurality of different data sources;
• and
• performing a cross-level alignment, a same-level alignment, or a combination thereof among the plurality of different data sources for said each of the plurality of resolution levels,
• wherein the creation of the hierarchical resolution tile representation is further based on the cross-level alignment, the same-level alignment, or a combination thereof,
• wherein the cross-level alignment is performed between two non-neighboring resolution levels of the plurality of resolutions levels.