[gdal-dev] could GDAL enforce towgs84=0,0,0 for ETRS89-based CRSs?

[Maciej Sieczka]

Another interesting thing: reprojecting rasters using an EPSG code of an
ETRS89 based CRS, results in a GeoTIFF header lacking the latlong
boundaries (the last 5 lines of gdalinfo output below):

$ gdalwarp -t_srs EPSG:3035 N51E016.hgt srtm_etrs89.tif

$ gdalinfo srtm_etrs89.tif

Driver: GTiff/GeoTIFF
Files: srtm_etrs89.tif
Size is 1023, 1516
Coordinate System is:
PROJCS["ETRS89 / ETRS-LAEA",
     GEOGCS["ETRS89",
         DATUM["European_Terrestrial_Reference_System_1989",
             SPHEROID["GRS 1980",6378137,298.2572221010002,
                 AUTHORITY["EPSG","7019"]],
             AUTHORITY["EPSG","6258"]],
         PRIMEM["Greenwich",0],
         UNIT["degree",0.0174532925199433],
         AUTHORITY["EPSG","4258"]],
     UNIT["metre",1,
         AUTHORITY["EPSG","9001"]],
     AUTHORITY["EPSG","3035"]]
Origin = (4732497.919957611709833,3233119.219332384876907)
Pixel Size = (77.290356972219669,-77.290356972219669)
Metadata:
   AREA_OR_POINT=Area
Image Structure Metadata:
   INTERLEAVE=BAND
Corner Coordinates:
Upper Left  ( 4732497.920, 3233119.219)
Lower Left  ( 4732497.920, 3115947.038)
Upper Right ( 4811565.955, 3233119.219)
Lower Right ( 4811565.955, 3115947.038)
Center      ( 4772031.938, 3174533.129)
Band 1 Block=1023x4 Type=Int16, ColorInterp=Gray



Whereas the same raster reprojected to e.g. a Pulkovo 1942(58) based CRS
has these latlon coordinates in place:

$ gdalwarp -t_srs EPSG:2174 N51E016.hgt srtm_pulkovo.tif

$ gdalinfo srtm_pulkovo.tif

Driver: GTiff/GeoTIFF
Files: srtm_pulkovo.tif
Size is 909, 1444
Coordinate System is:
PROJCS["Pulkovo 1942(58) / Poland zone IV",
     GEOGCS["Pulkovo 1942(58)",
         DATUM["Pulkovo_1942_58",
             SPHEROID["Krassowsky 1940",6378245,298.2999999999985,
                 AUTHORITY["EPSG","7024"]],
             AUTHORITY["EPSG","6179"]],
         PRIMEM["Greenwich",0],
         UNIT["degree",0.0174532925199433],
         AUTHORITY["EPSG","4179"]],
     PROJECTION["Oblique_Stereographic"],
     PARAMETER["latitude_of_origin",51.67083333333333],
     PARAMETER["central_meridian",16.67222222222222],
     PARAMETER["scale_factor",0.9998],
     PARAMETER["false_easting",3703000],
     PARAMETER["false_northing",5627000],
     UNIT["metre",1,
         AUTHORITY["EPSG","9001"]],
     AUTHORITY["EPSG","2174"]]
Origin = (3655914.793169156182557,5663915.491245908662677)
Pixel Size = (77.265039270892487,-77.265039270892487)
Metadata:
   AREA_OR_POINT=Area
Image Structure Metadata:
   INTERLEAVE=BAND
Corner Coordinates:
Upper Left  ( 3655914.793, 5663915.491) ( 15d59'11.37"E, 52d 0'2.46"N)
Lower Left  ( 3655914.793, 5552344.775) ( 16d 0'5.03"E, 50d59'51.91"N)
Upper Right ( 3726148.714, 5663915.491) ( 17d 0'33.70"E, 52d 0'7.90"N)
Lower Right ( 3726148.714, 5552344.775) ( 17d 0'7.31"E, 50d59'57.19"N)
Center      ( 3691031.754, 5608130.133) ( 16d29'59.40"E, 51d30'3.86"N)
Band 1 Block=909x4 Type=Int16, ColorInterp=Gray

Why the difference?

Maciek

-- 
Maciej Sieczka
www.sieczka.org