Web-Enabled Raster GIS Services for Large Image and Map Databases

While there is a rapidly increasing demand for flexible, ubiquitous access to ever-growing archives of raster images and maps of various types, data management technology lags behind, as raster structures (i.e., arrays) for a long time have been neglected in database research. File-based solutions prevail in products, and in research only prototypes with relatively narrow functionality have been tested. The RasGEO database application provides interactive navigation on unbounded continuous raster maps as well as ad-hoc generation of compound map products. RasGEO integrates all kind of rasterized map data, up to user-defined hyperspectral imagery and DEMs. The tool is implemented as a servlet-based Web application on top of the RasDaMan multidimensional DBMS. RasGEO user input is transformed into a query sent to the DBMS server. The server's response is a JPEG image which RasGEO forwards to the client. Any Web browser can be used, as the front end is purely HTML based. RasDaMan and RasGEO are commercial products operational at many sites, deployed with continuous aerial images in excess of .5 TB.