StarSpan is designed to bridge the raster and vector worlds of spatial analysis using fast algorithms for pixel level extraction from geometry features (points, lines, polygons). StarSpan generates databases of extracted pixel values (from one or a set of raster images), fused with the database attributes from the vector files. This allows a user to do statistical analysis of the pixel vs. attribute data in many existing packages and can greatly speed up classification training and testing. See the documentation for more details about commands, operations, and options.
This development has been possible thanks to California State Department of Boating and Waterways.
StarSpan should compile and run on most Unix flavor (including MacOs X and Windows via MinGW) although it has been mainly tested on Linux and MacOS X. StarSpan's core program is run from the command line. An experimental Java-based graphical user interface (GUI) is also available though no longer currently maintained.
StarSpan requires the GDAL and GEOS libraries properly installed on your system. Please note that starspan currently requires GEOS <= 3.2.x; GEOS 3.3+ will not work (see wiki page for details).
git clone git://github.com/Ecotrust/starspan.git
cd starspan
./configure
make
sudo make install
For more details, see INSTALL.
A common use case for starspan is to summarize raster pixel values by vector geometries. For instance, you may want to find the average NDVI value for each polygon in a shapefile.
starspan --vector zonemap.shp --raster ndvi.tif --stats avg \
--out-prefix ndvi --out-type table --summary-suffix _stats.csv
This would output a csv file named test_stats.csv which would provide statistics for each
polygon feature, one per row.
FID,id,RID,numPixels,avg_Band1
0,1,ndvi.tif,2890,3.869815
2,3,ndvi.tif,225,4.781782
3,4,ndvi.tif,682,4.871310
This is an open source software project and you are welcome to use the tool and contribute to this ongoing project. Please read the copyright agreement (copyright.txt).
The original project was developed at UC Davis (formerly housed at
http://casil.ucdavis.edu/projects/starspan/). The project is being moved
to github, unfortunately without any of the CVS history. It is currently
being maintained by perrygeo with support from Ecotrust.
Documentation, as you may notice, is very lacking. I hope to remedy this in the future. Please bear with us as we make the transition.