Opened 10 years ago

Last modified 9 years ago

#5670 closed defect

Incorrect False Northing extracted from GEOTIFF Citation geokeys — at Initial Version

Reported by: murphke1 Owned by: warmerdam
Priority: normal Milestone: 2.0.0
Component: default Version: unspecified
Severity: normal Keywords: Georegistration
Cc:

Description

I have a theoretically matching GEOTIFF DEM and MrSid imagery in State Planes/Alaska. When extracting WKT using GDAL, the MrSid comes out correctly and the GEOTIFF does not. The significant difference appears to be that the MrSid ends up with the "False Easting" properly in feet, while the Geotiff ends up with the "False Easting" with a value that is clearly in meters but labelled as "feet". The GEOTIFF WKT also ends up with the PCS code 26934 used as the EPSG Authority listed for the Units (instead of the proper 9003). The GEOTIFF contains the proper PCS and LinearUnits keys, but GDAL appears to end up lousing up the false easting when it parses the IMAGINE Geotiff citation keys. If I create a copy of the GEOTIFF that is exactly the same save for blanking the Citation Geokeys then everything works properly. Attempting to get customer permission to provide the data.

Correct WKT from MrSid: PROJCS["NAD83 / Alaska zone 4",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS 1980",6378137,298.2572221010002,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433],AUTHORITY["EPSG","4269"]],PROJECTIONTransverse_Mercator,PARAMETER["latitude_of_origin",54],PARAMETER["central_meridian",-150],PARAMETER["scale_factor",0.9999],PARAMETER["false_easting",1640416.666666667],PARAMETER["false_northing",0],UNIT["US survey foot",0.3048006096012192,AUTHORITY["EPSG","9003"]]]

Incorrect WKT from GEOTIFF: PROJCS["NAD_1983_StatePlane_Alaska_4_FIPS_5004_Feet",GEOGCS["NAD83",DATUM["North_American_Datum_1983",SPHEROID["GRS 1980",6378137,298.2572221010002,AUTHORITY["EPSG","7019"]],AUTHORITY["EPSG","6269"]],PRIMEM["Greenwich",0],UNIT["degree",0.0174532925199433],AUTHORITY["EPSG","4269"]],PROJECTIONTransverse_Mercator,PARAMETER["latitude_of_origin",54],PARAMETER["central_meridian",-150],PARAMETER["scale_factor",0.9999],PARAMETER["false_easting",5381933.680555555],PARAMETER["false_northing",0],UNIT["us_survey_feet",0.3048006096012192],AUTHORITY["EPSG","26934"]]

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