Method for generating three-dimensional terrain feature points on irregular triangulation network

Abstract

The invention provides a method for generating three-dimensional terrain feature points on an irregular triangulation network. The method comprises the following steps of: (1) extracting a three-dimensional terrain detail feature area; (2) intelligently interpolating three-dimensional feature points into the terrain feature area; (3) harmonizing drainage feature factors; and (4) generating the three-dimensional terrain feature points by taking terrain details into account. According to the method for generating the three-dimensional terrain feature points on the irregular triangulation network, terrain feature analysis, terrain feature extraction, terrain positive / negative trend judgment, drainage relationship harmonization, water elevation calculation, terrain detail optimization and refining and the like can be automatically realized on the irregular triangulation network, and the problems of low terrain detail accuracy and terrain detail loss when the irregular triangulation network is constructed by using a contour line as a data source are solved; and the method can be widely used in the fields of terrain data detail refining and optimization, geoanalysis, digital elevation model (DEM) data generation and the like.

Description

technical field [0001] The invention relates to a method for selecting three-dimensional terrain features, in particular to a method for generating three-dimensional terrain feature points on an irregular triangulation network. Background technique [0002] Three-dimensional terrain feature points refer to some special points that determine the overall contour of the terrain, terrain undulations, and trends. From a mathematical point of view, three-dimensional coordinates are used to determine the sampling points of the two-dimensional surface of the terrain. Once these terrain feature points are determined, the outline, undulation, and direction of the entire two-dimensional surface describing the terrain can be roughly determined, so they play an extremely important role in terrain representation. [0003] The three-dimensional terrain feature points mainly include mountain tops, depression points, ridge points, valley points, saddle points, and water body range points. A...

AI Technical Summary

Problems solved by technology

The contour curvature discrimination method is to extract feature points from digital contour data. When extracting terrain feature points, the method first calculates the curvature of discrete points on each contour line, and then calculates the curvature of discrete points whose absolute value is greater than a certain threshold. Points are selected as terrain feature points. This method ignores the changing law of each contour line. When the threshold value is selected larger, many points on the terrain feature line will be lost. When the threshold value is selected smaller, the points that are not terrain features will be lost. The points on the line are mistakenly regarded as terrain feature points, and in areas with broken terrain or rough contour lines, it will be very difficult to extract terrain features; For symmetrical changes, the extracted terrain feature lines have a large degree of similarity, and most of the extracted terrain feature points do not match the terrain changes, and when the contour lines are not smooth or there is noise, the result is even worse

Images