Here's a more current link: http://www.gdal.org/gdaldem.html
And you could look into the VRT format to see if can help with the nodata problem. > You could use the OFFSITE value in the higher resolution layer. > Basically in this scheme, mapserver would render each layer, and any > place with an OFFSITE value would show the value from the layer under > it. > > A more basic problem is how do you want the elevation value to be > rendered to a visible image? You could use GDAL to pre-process the > SRTM DEMs (http://www.perrygeo.net/wordpress/?p=7), or use mapserver to > classify the DEM values to colors on the fly. > > Best Regards, > Brent Fraser > >> How do I construct a map file that can handle different resolutions of >> terrain, with fallback to lower resolution when a no-value is found? In >> Google Earth Fusion, I can specify multiple terrain sources and tell it >> which value(s) represent missing data, and it will then process the >> terrain, checking for availability of each type of terrain, falling back >> if there isn't any in a geographic area and falling back if there is >> missing data. >> >> For simple fallback based on area coverage, I can use a map file like >> the >> one below (using 30 Arcsecond SRTM and 1 Arcsecond DTED). Now, what >> would >> I need to do to have it use/interpolate data from the 30 Arcsecond >> values >> when there is a missing data/NODATA/hole in the DTED? In the file >> below, >> gdaltindex has been used to generate the coverage shapefiles. >> >> The example below is a simple one, and it would be really helpful to be >> able to have multiple terrain sources and a way to automatically fill >> voids the same way that transparency works with raster image layers. >> Specifying that terrain values are posts and not pixels would be good >> too, >> but lower priority. >> >> Xander >> >> MAP >> NAME "srtm" >> EXTENT -180 -90 180 90 >> SIZE 512 512 >> UNITS DD >> IMAGETYPE bil >> >> PROJECTION >> "init=epsg:4326" >> END >> >> OUTPUTFORMAT >> NAME "bil" >> DRIVER "GDAL/EHdr" >> MIMETYPE "image/bil" >> EXTENSION "bil" >> IMAGEMODE INT16 >> END >> >> OUTPUTFORMAT >> NAME "bil16" >> DRIVER "GDAL/EHdr" >> MIMETYPE "application/bil16" >> EXTENSION "bil" >> IMAGEMODE INT16 >> END >> >> OUTPUTFORMAT >> NAME "gtiff_16" >> DRIVER "GDAL/GTiff" >> MIMETYPE "image/tiff" >> EXTENSION "tif" >> IMAGEMODE INT16 >> END >> >> WEB >> IMAGEPATH "/tmp/" >> IMAGEURL "/tmp/" >> LOG "/tmp/srtm.err" >> METADATA >> wms_title "SRTM Terrain" >> END >> END >> >> # >> # Coarse (30 ArcSecond) terrain. There is worldwide coverage, so this >> # is good for areas uncovered by SRTM data, as well as for high >> # scale values. >> # >> LAYER >> NAME "srtm" >> TILEINDEX "SRTM30/bathmetry.shp" >> TYPE RASTER >> PROCESSING "RESAMPLE=BICUBIC" >> STATUS ON >> >> METADATA >> "wms_title" "SRTM 30 ArcSecond Bathmetry" >> "wms_group_title" "srtm30" >> "wms_srs" "epsg:4326" >> "wms_style" "Default" >> "wms_extent" "-180 -90 180 90" >> END >> >> MAXSCALEDENOM 1000000000 >> MINSCALEDENOM 10 >> END >> >> # >> # Moderate resolution (1 ArcSecond) terrain. Coverage is available >> worldwide >> # for most land areas between latitudes -60 and +60. >> # >> LAYER >> NAME "srtm" >> TILEINDEX "srt2f_1/srt2f_1.shp" >> TYPE RASTER >> PROCESSING "RESAMPLE=BICUBIC" >> STATUS ON >> >> METADATA >> "wms_title" "SRTM 1 ArcSecond Bathmetry" >> "wms_group_title" "srtm30" >> "wms_srs" "epsg:4326" >> "wms_style" "Default" >> "wms_extent" "-180 -60 180 60" >> END >> >> MAXSCALEDENOM 1000000 >> END >> >> END >> >> _______________________________________________ >> mapserver-users mailing list >> [email protected] >> http://lists.osgeo.org/mailman/listinfo/mapserver-users >> > > > > _______________________________________________ > mapserver-users mailing list > [email protected] > http://lists.osgeo.org/mailman/listinfo/mapserver-users > _______________________________________________ mapserver-users mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/mapserver-users
