Opened 15 years ago
Closed 15 years ago
#3017 closed defect (fixed)
GDAL changes projection parameter values
Reported by: | peifer | Owned by: | warmerdam |
---|---|---|---|
Priority: | normal | Milestone: | 1.6.2 |
Component: | GDAL_Raster | Version: | 1.6.0 |
Severity: | normal | Keywords: | LAEA morph |
Cc: |
Description
Hermann wrote to the gdal mailing list:
> My original ccordinate system is > PROJCS["ETRS_1989_LAEA_L52_M10", > GEOGCS["GCS_ETRS_1989", > DATUM["European_Terrestrial_Reference_System_1989", > SPHEROID["GRS_1980",6378137.0,298.257222101]], > PRIMEM["Greenwich",0.0], > UNIT["Degree",0.0174532925199433]], > PROJECTION["Lambert_Azimuthal_Equal_Area"], > PARAMETER["False_Easting",4321000.0], > PARAMETER["False_Northing",3210000.0], > PARAMETER["Central_Meridian",10.0], <--- > PARAMETER["Latitude_Of_Origin",52.0], <--- > UNIT["Meter",1.0]] > ... after using gdal_translate, the coordinate system changes to: > PROJCS["ETRS_1989_LAEA_L52_M10", > GEOGCS["GCS_ETRS_1989", > DATUM["European_Terrestrial_Reference_System_1989", > SPHEROID["GRS 1980",6378137,298.2572221010042, > AUTHORITY["EPSG","7019"]], > AUTHORITY["EPSG","6258"]], > PRIMEM["Greenwich",0], > UNIT["degree",0.0174532925199433]], > PROJECTION["Lambert_Azimuthal_Equal_Area"], > PARAMETER["latitude_of_center",0], <-- > PARAMETER["longitude_of_center",0], <-- > PARAMETER["false_easting",4321000], > PARAMETER["false_northing",3210000], > UNIT["metre",1, > AUTHORITY["EPSG","9001"]]]
Frank replied:
The problem appears to be that for the first file the coordinate system is being read from the .aux file, but not properly converted from ESRI format to OGR format. So the parameters should be named latitude_of_center and longitude_of_center but instead are still using the ESRI names of Central_Meridian and Latitude_Of_Origin. The GeoTIFF writer does not notice these values and writes default zeros for the lat/long of center parameters in the geotiff file and that is what you get on read back.
I believe this is a failure of the .aux file reading logic to normalize the coordinate system properly. Looking in the morphFromESRI() code there appears to be handling for this transformation, so I suspect it is subtly broken, or not being invoked by the .aux reader.
Attachments (1)
Change History (3)
by , 15 years ago
Attachment: | lceugr100_06_pct.aux added |
---|
comment:1 by , 15 years ago
comment:2 by , 15 years ago
Keywords: | LAEA morph added |
---|---|
Milestone: | → 1.6.2 |
Resolution: | → fixed |
Status: | new → closed |
I think this is fixed in GDAL 1.7.0dev. See :
whereas with GDAL 1.6.x, I also get "Central_Meridian" and "Latitude_Of_Origin". By looking (quickly) at the diff between trunk and GDAL 1.6.x in ogr/ogr_srs_esri.cpp, it appears that substantial work has been done, and in particular for LAEA projection to remap the parameter name.
Probably this change :