Research Of The Digital Elevation Model Based On GeoGIS

Based on the theory research of digital elevation model, the paper designs and implements a module, which uses grid model and triangular irregular network model as the basic GeoGIS digital elevation models. The module covers digital elevation model’s establishment, conversion and application etc., and generally satisfies the needs of the terrain analysis in digital geological survey based on GeoGIS.For the implementation of level of detail model and the progressive transmission of digital elevation model mesh, on the basis of mesh simplification technology, the paper proposes a progressive mesh model based on collapse tree combining the existing related technologies. This model overcomes disadvantage of the general progressive mesh, which must be strictly carried out in reversed order in the process of changing from simplified mesh to fine mesh, achieves a disorder simplified mesh expansion (the inverse of the folding operation), which improves the flexibility of progressive mesh model and can meet the fining of mesh in a specific area.This paper also implements the optimized algorithm by combining the characteristics of this model and the simulated annealing algorithm. Generate a series of new simplified mesh through folding and unfolding operation, and use simulated annealing algorithm to control and optimize the mesh in the global scope. The experiment shows that the algorithm can optimize the mesh and get better global simplified results in a certain degree.