A Tool to Query and Visualize the Complete SRTM Data Set Indexed by the Q-tree in an Open GIS

Geospatial data are increasingly frequent and useful in Visualization, Virtual Reality and, of course, Geographic Information System (GIS) applications due to its realism. Most of the geospatial data sources are heterogeneous because they come from diverse satellites and the data are of different nature. Nevertheless, the Shuttle Radar Topographic Mission (SRTM) provided an unique source of uniform data of the almost entire Earth´s surface. On the other hand, to make effective and efficient regional queries over these SRTM data, the indexing with a space partitioning data structure is needed, making easy the visualization of their results. This paper presents a tool to query an visualize the complete SRTM data set indexed by the Q-tree multidimensional index structure. The tool .is totally integrated into the VTBuilder, an open GIS, allowing the visual selection of rectangular and polygonal spatial query regions and the retrieval of the query results by using the multidimensional index. The query results of the selected regions can also be exported to files with two specific format types for their further analysis. Finally, the visualization takes place in both 2D and virtual 3D rendering for its visual analysis.