Large-scale Multidimensional Coverage Databases

With GIS technology for Web-enabled vector and meta data access becoming mature, the next quest is towards fast, flexible services on extremely large raster data assets. Currently 2-D images (satellite imagery, ortho photos) prevail, but at the horizon higher-dimensional objects appear, such as 3-D time satellite image time series and seismic data, and 4-D climate simulations. At the same time, database researchers are getting aware of the specific challenges such multidimensional coverages pose. Some promising recent work shows that database systems with optimising query languages actually are superior to file-based systems in performance, flexibility, and scalability. We demonstrate three applications: a 2-D ortho photo maintained by the Bavarian State Survey, a 3-D AVHRR time series deployed as experimental Web service by the German Aerospace Association, and a 4-D climate simulation database implemented by Max-Planck-Institute for Meteorology. All of them use the identical underlying database technology, namely RasDaMan / Oracle with the RasDaMan raster query language. WHY RASTER DATABASES? * Increasingly raster data are complementing vectorial data in geo applications. On the one hand, storage facilities allow to keep substantial raster archives online, on the other hand acquisition of raster data is rapidly getting easier and less expensive. Additionally, timeliness of raster imagery is significantly higher as compared to vector data, due to the easier acquisition. This advance in technology is paired by a rapidly increasing user demand for flexible, ubiquitous access to large archives of raster images and maps of various types. A broad range of raster imagery has to be considered in geo data management: grayscale and colour aerial images, multiand hyperspectral satellite images, topographical raster maps, RADAR and laser scan, and Digital * Work in part funded by the European Commission under grant no. IST-1999-11009 ESTEDI, www.estedi.org, and IST2000-28766 EuroClim, http://euroclim.nr.no. 26th GITA Annual Conference, San Antonio, March 2 – 5, 2003