Tyler, I think the following might work. Pick up the NAD27toATS77 and ATS77toNAD83 here: http://georepository.com/search/by-name/query/Ats77/transformation_page/1/#transformation
Add the two multiband grids together somehow (open gsb's as raster in qgis) i.e. Band 1 longitude shift and band 2 latitude shift. The other two bands can be zero. Save the new grid as a multi band geotif. From a command prompt Navigate to gdal_translate located in QGIS 2.16\Bin\ or equivalent Then type: gdal_translate <path\multibandgeo.tif> -of NTV2 <path\new_ntv2_grid.gsb> This will create new_ntv2_grid.gsb which will be NAD27toNAD83 ( a proxy for wgs84 as far as proj4 is concerned). Just remember to put the gsb on your from string, and your to string +towgs84=0,0,0,0,0,0,0 -- Sent from: http://osgeo-org.1560.x6.nabble.com/QGIS-User-f4125267.html _______________________________________________ Qgis-user mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
