The Research Of Multi-scale DEM Data Organization For Quickly Browsing The 3d Image

In recent years, emergencies occur unceasingly in our country , even in the world。How to deal with science and promptly and appropriately to emergencies is today our government has to face a major issue, and geographic information systems (GIS) visualization platform for the subject to provide an effective solution.。3D GIS platform for its fast browsing, display, query spatial information and statistically, spatial analysis and other special functions,Thus, it is government departments at all levels of decision-making and command and disposal of public emergencies has played a particularly important role.However, the accuracy of DEM data improved gradually with its advanced acquisition technology in recent years, especially the date of InSAR and Lidar, which accuracy achieve to Decimeter-level or even centimeter level. So, the efficiency of the key is how to organize this massive and multi-scale DEM data, to enable them to fast three-dimensional GIS platform, the display and browsing, and precise spatial analysis to determine the three-dimensional GIS platform.The paper mainly studies the key technologies for DEM data organization based on DEM data pre-processing and Builds a global DEM data organization model pyramids.And it further discusses lossy compression algorithm or lossless compression algorithm based on wavelet compression of DEM data, and proposes SPIHT coding of the data compression scheme combining SevenZip.In addition, The paper designs multi-scale DEM database based on Oracle Sapatial, and uses C # language to develop DEM storage software. Thus, saving storage, improve the transmission efficiency, so that in the scheduling, storage, display and browsing speed performance have been a larger increase, after evaluation, to reach the domestic advanced level in three-dimensional GIS platform.