Selon "Newcomb, Doug" <[email protected]>: > Thanks! > > That should work in this case to build the virtual raster. I'm still > curious about assigning the vertical datum to the rasters.
Doug, I'm a bit surprised that the HFA driver reports a SRS with a VERTCS node as a child of the PROJCS node. I believe this is an incorrect WKT definition. There should rather be a COMPD_CS root note with 2 children: a PROJCS node for the horizontal CRS and a VERTCS node for the vertical CRS. Perhaps this SRS string is defined in the .aux.xml sidecar files that are apparently present ? Regarding your question, there are a few EPSG codes that correspond to aCOMPD_CS, for example 6349. Otherwise, GDAL allows to build a custom COMPD_CS with the syntax EPSG:XXXX+YYYY where XXXX is the EPSG code of the horizontal SRS and YYYY the EPSG code of the vertical SRS. In your case that should be EPSG:6543+5703 I think So you can do things like "gdal_translate in.tif out.tif -a_srs EPSG:6543+5703" If you read back out.tif, you will only get the horizontal SRS by default. This was for backward compatibility reason I think. But if you specify "--config GTIFF_REPORT_COMPD_CS YES" you will get the COMPD_CS. Even > > Doug > > On Tue, Jun 9, 2015 at 1:48 AM, Hermann Peifer <[email protected]> wrote: > > > > > About your initial problem: > > > but gdalbuildvrt complained, informing me that > > > they were not in the same projection. > > > > What about using the below gdalbuildvrt option? > > > > Hermann > > > > -allow_projection_difference: > > (starting with GDAL 1.7.0) When this option is specified, the utility will > > accept to make a VRT even if the input datasets have not the same > > projection. Note: this does not mean that they will be reprojected. Their > > projection will just be ignored. > > > > Source: http://www.gdal.org/gdalbuildvrt.html > > > > > > > > On 2015-06-08 21:01, Newcomb, Doug wrote: > > > >> Hi Folks, > >> I have a directory of 783 .img format Lidar - based DEMs in the same > >> projection, North Carolina State Plane Feet (2011) , NAD 83 , NVD88. I > >> was going to use gdalbuildvrt to create a single virtual image for the > >> area, but gdalbuildvrt complained, informing me that they were not in > >> the same projection. > >> > >> A couple of quick bash scripts/commands > >> > >> for x in *.img; do gdalinfo $x >>img_info.txt;done > >> > >> and > >> grep PROJCS img_info.txt|sort|uniq -c > >> > >> gives me the following: > >> > >> 437 PROJCS["NAD_1983_2011_StatePlane_North_Carolina_FIPS_3200_Ft_US", > >> 346 PROJCS["NAD_1983_StatePlane_North_Carolina_FIPS_3200_Feet_2011", > >> > >> gdalinfo gives the following for each type of file ( origin section > >> clipped out) : > >> > >> Driver: HFA/Erdas Imagine Images (.img) > >> Files: D05_37_20878102_20141231.img > >> D05_37_20878102_20141231.img.aux.xml > >> Size is 1000, 1000 > >> Coordinate System is: > >> PROJCS["NAD_1983_2011_StatePlane_North_Carolina_FIPS_3200_Ft_US", > >> GEOGCS["GCS_NAD_1983_2011", > >> DATUM["NAD_1983_2011", > >> SPHEROID["GRS_1980",6378137.0,298.257222101]], > >> PRIMEM["Greenwich",0.0], > >> UNIT["Degree",0.017453292519943295]], > >> PROJECTION["Lambert_Conformal_Conic_2SP"], > >> PARAMETER["False_Easting",2000000.0], > >> PARAMETER["False_Northing",0.0], > >> PARAMETER["Central_Meridian",-79.0], > >> PARAMETER["Standard_Parallel_1",34.3333333333333], > >> PARAMETER["Standard_Parallel_2",36.1666666666667], > >> PARAMETER["Latitude_Of_Origin",33.75], > >> UNIT["Foot_US",0.30480060960121924], > >> VERTCS["NAVD_1988_Foot_US", > >> VDATUM["North_American_Vertical_Datum_1988"], > >> PARAMETER["Vertical_Shift",0.0], > >> PARAMETER["Direction",1.0], > >> UNIT["Foot_US",0.3048006096012192]]] > >> > >> > >> Driver: HFA/Erdas Imagine Images (.img) > >> Files: D05_37_20957301_20141231.img > >> D05_37_20957301_20141231.img.aux.xml > >> Size is 1000, 1000 > >> Coordinate System is: > >> PROJCS["NAD_1983_StatePlane_North_Carolina_FIPS_3200_Feet_2011", > >> GEOGCS["GCS_NAD_1983_2011", > >> DATUM["NAD_1983_2011", > >> SPHEROID["GRS_1980",6378137.0,298.257222101]], > >> PRIMEM["Greenwich",0.0], > >> UNIT["Degree",0.0174532925199433]], > >> PROJECTION["Lambert_Conformal_Conic_2SP"], > >> PARAMETER["False_Easting",2000000.002616666], > >> PARAMETER["False_Northing",0.0], > >> PARAMETER["Central_Meridian",-79.0], > >> PARAMETER["Standard_Parallel_1",34.33333333333334], > >> PARAMETER["Standard_Parallel_2",36.16666666666666], > >> PARAMETER["Latitude_Of_Origin",33.75], > >> UNIT["Foot_US",0.30480060960121924], > >> VERTCS["NAVD_1988_Foot_US", > >> VDATUM["North_American_Vertical_Datum_1988"], > >> PARAMETER["Vertical_Shift",0.0], > >> PARAMETER["Direction",1.0], > >> UNIT["Foot_US",0.3048006096012192]]] > >> > >> > >> > >> In theory, these should all be EPSG:6543, so just assigning the correct > >> horizontal projection/datum with the epsg code should make things > >> usable. (i.e, > >> gdal_translate -a_"srs epsg:6543" --config GDAL_CACHEMAX 512 -of GTiff > >> -co COMPRESS=DEFLATE -co PREDICTOR=3 in.img out.tif ) ( Thank you for > >> the EPSG:6543 projection support in GDAL 2.0!) > >> > >> However, this only assigns the horizontal infomation, how does one > >> assign a vertical datum with a horizontal EPSG code? > >> > >> I see the NVD88 code in vertcs.csv , but how would I implement it in the > >> above command? > >> > >> Using gdal 2.0 Beta2 > >> > >> > >> Doug > >> -- > >> Doug Newcomb > >> USFWS > >> Raleigh, NC > >> 919-856-4520 ext. 14 [email protected] <mailto:[email protected]> > >> > >> > --------------------------------------------------------------------------------------------------------- > >> The opinions I express are my own and are not representative of the > >> official policy of the U.S.Fish and Wildlife Service or Dept. of the > >> Interior. Life is too short for undocumented, proprietary data formats. > >> > >> > >> _______________________________________________ > >> gdal-dev mailing list > >> [email protected] > >> http://lists.osgeo.org/mailman/listinfo/gdal-dev > >> > >> > > > > > -- > Doug Newcomb > USFWS > Raleigh, NC > 919-856-4520 ext. 14 [email protected] > --------------------------------------------------------------------------------------------------------- > The opinions I express are my own and are not representative of the > official policy of the U.S.Fish and Wildlife Service or Dept. of the > Interior. Life is too short for undocumented, proprietary data formats. > -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
