[Qgis-user] QGIS 3.10.1A Geotiff Coordinate Transform Problem

[Mike Flannigan]

Thank you for so thoroughly explaining a problem
I have been having for about a month now.  I
was wondering if I was the only one.

I get errors:
proj_create_from_database: crs not found

and "Invalid data source".

and the file does not open.
I am looking forward to this being corrected
in future versions.


Mike


On 1/19/20 11:19 AM, qgis-user-request at lists.osgeo.org wrote:
> Date: Sat, 18 Jan 2020 22:10:38 -0500
> From: Stewart Holt<stewartbholt at gmail.com>
> To:qgis-user at lists.osgeo.org
> Subject: [Qgis-user] QGIS 3.10.1A Geotiff Coordinate Transform Problem
> Message-ID:
> 	<CAFnvfO2JmfTh8rhCU4V7ytDJU93EOgeQkUMm8T3-pCfmpCpkxA at mail.gmail.com>
> Content-Type: text/plain; charset="utf-8"
>
> I have QGIS 3.10.1 installed and I can no longer display historic USGS
> geofiffs. I probably have not used these since at least version 3.8. I got
> a message saying that the transform could not be done. The file had a CRS
> that was apparently user generated (automatically) based on NAD27. I have
> over 50 of these files and each seems to have a different User CRS. The
> project CRS is EPSG:3857.
>
> The transform failure message provided a link to download the grid shift
> file ntv2_0.gsb. I clicked the link which downloaded a zip file. I
> extracted only  ntv2_0.gsb from it and browsed to it using the "Install
> ntv2_0.gsb from Folder..." button. It installed with a message indicating
> success. I closed and reopened the project as directed, and selected the
> geotiff file layer. There was no error but the canvas was obviously far
> from the rest of my project (SE US). I zoomed to the geotiff layer and
> selected the Google satellite view. I zoomed out until I recognized the
> area as being northern Africa. Approximate center coordinates
> were: 32.78461469, -0.00187768.
>
> The projection file GA_Hightower Bald_245924_1988_24000_geo.tif.prj
> contains this:
>
> PROJCS["Transverse_Mercator",GEOGCS["GCS_North_American_1927",DATUM["D_North_American_1927",SPHEROID["Clarke_1866",6378206.4,294.9786982]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]],PROJECTION["Transverse_Mercator"],PARAMETER["latitude_of_origin",0],PARAMETER["central_meridian",-83.56299999999918],PARAMETER["scale_factor",1],PARAMETER["false_easting",0],PARAMETER["false_northing",0],UNIT["Meter",1]]
>
> Previously, I had not even downloaded the .prj files because QGIS seemed to
> handle the geotiff files with no problem. I tried downloading the tfw and
> prj files but it made no difference. I also tried to set the CRS for the
> geotiff based on the prj file and that gave the same result.
>
> I think that after installing the grid shift file, there is no error
> detected but the transformation fails.
>
> Has anyone had any experience with USGS geotiff files and QGIS 3.10.1?
>
> A download link for the files above is:
> ftp://rockyftp.cr.usgs.gov/vdelivery/Datasets/Staged/Maps/HistoricalTopo/GeoTIFF/GA/
>
> Any help to solve this would be appreciated.
>
> Thanks,
>
> Stewart Holt
> Georgia Appalachian Trail Club