Hello, I've created a new project (CRS=EPSG:25832 ETRS89/UTM32N) using QGIS 3.10.8 (on Debian 11, PROJ version 7.1.0) which contains several multi polygon layers (land parcels). Those layers were imported from shape files containing either EPSG:25832 (as is the project) or legacy EPSG:31468 (DHDN/3° Gauss-Krueger Zone 4) data. QGIS gave me a couple of transformation options via Project -> Properties -> CRS -> Datum Transformations but none of those is accurate enough for my purposes. I need sub centimeter accuracy.
Therefore I'd like to go for an NTv2 grid based approach using a gsb file. I've put the grid file to /usr/share/proj/kanu_ntv2_oberfranken.gsb and added several rows to /usr/share/qgis/resources/srs.db like so (don't remember all the variations): INSERT INTO tbl_datum_transform VALUES (99999, 1000997, 4314, 4326, 9615, 'kanu_ntv2_mittelfranken.gsb', NULL, NULL, NULL, NULL, NULL, NULL, 'Für ALKIS Bayern, amtliche Gitterdatei des LDBV', 'Für Genauigkeitsanforderungen im cm Bereich', 1, 0, NULL); or INSERT INTO tbl_datum_transform VALUES (99999, 1000998, 4314, 4258, 9615, 'kanu_ntv2_mittelfranken.gsb', NULL, NULL, NULL, NULL, NULL, NULL, 'Für ALKIS Bayern, amtliche Gitterdatei des LDBV', 'Für Genauigkeitsanforderungen im cm Bereich', 1, 0, 3339); No matter what I add there QGIS never lists a new transformation option in Project -> Properties -> CRS -> Datum Transformations -> '+' when selecting Source = EPSG:31468 and Destination = EPSG:25832. I only get +proj=pipeline +step +inv +proj=tmerc +lat_0=0 +lon_0=12 +k=1 +x_0=4500000 +y_0=0 +ellps=bessel +step +proj=hgridshift +grids=de_adv_BETA2007.tif +step +proj=utm +zone=32 +ellps=GRS80 +proj=pipeline +step +inv +proj=tmerc +lat_0=0 +lon_0=12 +k=1 +x_0=4500000 +y_0=0 +ellps=bessel +step +proj=push +v_3 +step +proj=cart +ellps=bessel +step +proj=helmert +x=598.1 +y=73.7 +z=418.2 +rx=0.202 +ry=0.045 +rz=-2.455 +s=6.7 +convention=position_vector +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=utm +zone=32 +ellps=GRS80 +proj=pipeline +step +inv +proj=tmerc +lat_0=0 +lon_0=12 +k=1 +x_0=4500000 +y_0=0 +ellps=bessel +step +proj=push +v_3 +step +proj=cart +ellps=bessel +step +proj=helmert +x=597.1 +y=71.4 +z=412.1 +rx=0.894 +ry=0.068 +rz=-1.563 +s=7.58 +convention=position_vector +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=utm +zone=32 +ellps=GRS80 +proj=pipeline +step +inv +proj=tmerc +lat_0=0 +lon_0=12 +k=1 +x_0=4500000 +y_0=0 +ellps=bessel +step +proj=push +v_3 +step +proj=cart +ellps=bessel +step +proj=helmert +x=584.8 +y=67 +z=400.3 +rx=0.105 +ry=0.013 +rz=-2.378 +s=10.29 +convention=position_vector +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=utm +zone=32 +ellps=GRS80 +proj=pipeline +step +inv +proj=tmerc +lat_0=0 +lon_0=12 +k=1 +x_0=4500000 +y_0=0 +ellps=bessel +step +proj=push +v_3 +step +proj=cart +ellps=bessel +step +proj=helmert +x=590.5 +y=69.5 +z=411.6 +rx=-0.796 +ry=-0.052 +rz=-3.601 +s=8.3 +convention=position_vector +step +inv +proj=cart +ellps=GRS80 +step +proj=pop +v_3 +step +proj=utm +zone=32 +ellps=GRS80 I would expect there to be something like +nadgrids=kanu_ntv2_oberfranken.gsb. What could be going wrong here? Am I missing something? Thank you in advance and best regards! Thomas _______________________________________________ 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
