System and method of processing digital terrain information

Claim 1

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: obtaining digital terrain elevation data posts; calculating a normal relative to the terrain surface for each digital terrain elevation data post; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 2

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: obtaining digital terrain elevation data posts; calculating a normal relative to the terrain surface for each digital terrain elevation data post; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 9

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: processing digital terrain elevation data using a graphics application programming interface (API) to create a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; calculating a normal relative to the terrain surface for each digital terrain elevation data post; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 10

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: processing digital terrain elevation data using a graphics application programming interface (API) to create a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; calculating a normal relative to the terrain surface for each digital terrain elevation data post; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 17

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: processing digital terrain elevation data using a graphics application programming interface (API) to create a texture image of a plurality of terrain blocks, each terrain bock having a terrain elevation data post; calculating a normal value relative to the terrain surface for each digital terrain elevation data post as two fixed point numbers corresponding respectively to a slope tilt value and slope azimuth value; concatenating the two fixed point numbers into a color table reference number for each digital terrain elevation data post; applying each color table reference number as part of a color index for a color table; and applying an offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 18

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: processing digital terrain elevation data using a graphics application programming interface (API) to create a texture image of a plurality of terrain blocks, each terrain bock having a terrain elevation data post; calculating a normal value relative to the terrain surface for each digital terrain elevation data post as two fixed point numbers corresponding respectively to a slope tilt value and slope azimuth value; concatenating the two fixed point numbers into a color table reference number for each digital terrain elevation data post; applying each color table reference number as part of a color index for a color table; and applying an offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 25

A system for processing digital terrain elevation data (DTED) for a digital terrain map comprising: a graphics application programming interface for receiving and processing digital terrain elevation data and creating a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; a processor for calculating a normal relative to the terrain surface for each digital terrain elevation data post, forming a color table reference number for each post and used as an index in a color table, and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 26

A system for processing digital terrain elevation data (DTED) for a digital terrain map comprising: a graphics application programming interface for receiving and processing digital terrain elevation data and creating a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; a processor for calculating a normal relative to the terrain surface for each digital terrain elevation data post, forming a color table reference number for each post and used as an index in a color table, and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 30

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: obtaining digital terrain elevation data posts; calculating a normal relative to the terrain surface for each digital terrain elevation data post within a polar coordinate system wherein the normal comprises a slope tilt value and a slope azimuth value as two fixed point numbers that are concatenated into a color table reference number; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying an offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 31

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: obtaining digital terrain elevation data posts; calculating a normal relative to the terrain surface for each digital terrain elevation data post within a polar coordinate system wherein the normal comprises a slope tilt value and a slope azimuth value as two fixed point numbers that are concatenated into a color table reference number; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying an offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 32

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: processing digital terrain elevation data using a graphics application programming interface (API) to create a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; calculating a normal relative to the terrain surface for each digital terrain elevation data post within a polar coordinate system wherein the normal comprises a slope tilt value and a slope azimuth value as two fixed point numbers that are concatenated into a single table reference number; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying an offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 33

A method of processing digital terrain elevation data (DTED) for a digital terrain map comprising the steps of: processing digital terrain elevation data using a graphics application programming interface (API) to create a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; calculating a normal relative to the terrain surface for each digital terrain elevation data post within a polar coordinate system wherein the normal comprises a slope tilt value and a slope azimuth value as two fixed point numbers that are concatenated into a single table reference number; forming a color table reference number used in a color table for each digital terrain elevation data post; and applying an offset to each reference number in the color table for generating a correct sun-angle color when the heading angle of the digital terrain map changes.

Claim 34

A system for processing digital terrain elevation data (DTED) for a digital terrain map comprising: a graphics application programming interface for receiving and processing digital terrain elevation data and creating a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; a processor for calculating a normal relative to the terrain surface for each digital terrain elevation data post, forming a color table reference number as a concatenated value obtained from a slope tilt value and a slope azimuth value for each post and used as an index in a color table, and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angel of digital terrain map changes.

Claim 35

A system for processing digital terrain elevation data (DTED) for a digital terrain map comprising: a graphics application programming interface for receiving and processing digital terrain elevation data and creating a texture image of a plurality of terrain blocks, each terrain block having a terrain elevation data post; a processor for calculating a normal relative to the terrain surface for each digital terrain elevation data post, forming a color table reference number as a concatenated value obtained from a slope tilt value and a slope azimuth value for each post and used as an index in a color table, and applying a single offset to each reference number in the color table for generating a correct sun-angle color when the heading angel of digital terrain map changes.