Init from EPSG / GeoTiff-Import EPSG:21781: Wrong Datum
kopa
Global Mapper User
When I use the 'init from epsg'-function with epsg:21781, GM displays the wrong datum as default ('ch1903+' instead of 'ch1903'. I also tried to define a custom epsg code within epsg_codes.txt with the correct datum ch1903, but GM change it automatically in ch1903+.
The same problem is, when I want to import a Geotiff with EPSG:21781 in metadata. Then GM interprets the worng datum too.
Very strange is following behavior: After importing a geotiff with epsg:21781 and saving the GM-Workspace (where the wrong datum CH1903+ is displayed in the bottom right corner), the correct datum ch1903 is dispayed when reopening the workspace. But if I want to export the displayed raster image into a geotiff, GM writes the wrong epsg-code 30600 (local cs) in the metadata of the Geotiff-File.
There is a sample geotiff file with epsg 21781 on my dropbox: https://dl.dropboxusercontent.com/u/33938340/Ortho5cm_21781.tif
The same problem is, when I want to import a Geotiff with EPSG:21781 in metadata. Then GM interprets the worng datum too.
Very strange is following behavior: After importing a geotiff with epsg:21781 and saving the GM-Workspace (where the wrong datum CH1903+ is displayed in the bottom right corner), the correct datum ch1903 is dispayed when reopening the workspace. But if I want to export the displayed raster image into a geotiff, GM writes the wrong epsg-code 30600 (local cs) in the metadata of the Geotiff-File.
There is a sample geotiff file with epsg 21781 on my dropbox: https://dl.dropboxusercontent.com/u/33938340/Ortho5cm_21781.tif
Comments
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The problem is that many PRJ files will use the text 'CH1903' for both CH1903 and CH1903+ datums, so Global Mapper had some trouble distinguishing them. I have improved this now so hopefully it will stay consistent and as long as CH1903+ is somewhere in the PRJ file it will be recognized. I have placed a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v14.xx installation folder to give it a try. If you are using the 64-bit v14 version there is a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14_64bit.zip .
Thanks,
Mike
Global Mapper Guru
geohelp@bluemarblegeo.com
Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
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