1.. _raster.rasdaman: 2 3================================================================================ 4Rasdaman GDAL driver 5================================================================================ 6 7.. shortname:: Rasdaman 8 9.. build_dependencies:: raslib 10 11Rasdaman is a raster database middleware offering an SQL-style query 12language on multi-dimensional arrays of unlimited size, stored in a 13relational database. See `www.rasdaman.org <http://www.rasdaman.org>`__ 14for the open-source code, documentation, etc. Currently rasdaman is 15under consideration for OSGeo incubation. 16 17In our driver implementation, GDAL connects to rasdaman by defining a 18query template which is instantiated with the concrete subsetting box 19upon every access. This allows delivering 2-D cutouts from n-D data sets 20(such as hyperspectral satellite time series, multi-variable climate 21simulation data, ocean model data, etc.). In particular, virtual imagery 22can be offered which is derived on demand from ground truth data. Some 23more technical details are given below. 24 25| The connect string syntax follows the WKT Raster pattern and goes like 26 this: 27| rasdaman: query='select a[$x_lo:$x_hi,$y_lo:$y_hi] from MyImages as a' 28 [tileXSize=1024] [tileYSize=1024] [host='localhost'] [port=7001] 29 [database='RASBASE'] [user='rasguest'] [password='rasguest'] 30 31The rasdaman query language (rasql) string in this case only performs 32subsetting. Upon image access by GDAL, the $ parameters are substituted 33by the concrete bounding box computed from the input tile coordinates. 34 35| However, the query provided can include any kind of processing, as 36 long as it returns something 2-D. For example, this determines the 37 average of red and near-infrared pixels from the oldest image time 38 series: 39| query='select ( a.red+a.nir ) /2 [$x_lo:$x_hi,$y_lo:$y_hi, 0 ] from 40 SatStack as a' 41 42Currently there is no support for reading or writing georeferencing 43information. 44 45See Also 46-------- 47 48- `Rasdaman Project <http://www.rasdaman.org/>`__ 49