Re: [Qgis-user] NTV2 Grid Shits

I have no need to transform from ATS77 to NAD27 but it sounds like a good idea if one had to. I have 2 GSB Files PE7783V2.gsb from the GeoCalc Software designed by GeoNB for PEI to transform from ATS77 to NAD83 and NTv2.gsb which is a national gsb for going from NAD27 to NAD83. I came back to this

Re: [Qgis-user] NTV2 Grid Shits

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

Re: [Qgis-user] NTV2 Grid Shits

Am 24.10.2017 um 22:42 schrieb stevejking: Tyler, NAD27 and ATS77 don't seem to share the same ellipsoid. spatialreference.org lists ATS77 as +proj=sterea +lat_0=47.25 +lon_0=-63 +k=0.12 +x_0=70 +y_0=40 +a=6378135 +b=6356750.304921594 +units=m +no_defs It's missing a +towgs84= or

Re: [Qgis-user] NTV2 Grid Shits

Tyler, NAD27 and ATS77 don't seem to share the same ellipsoid. spatialreference.org lists ATS77 as +proj=sterea +lat_0=47.25 +lon_0=-63 +k=0.12 +x_0=70 +y_0=40 +a=6378135 +b=6356750.304921594 +units=m +no_defs It's missing a +towgs84= or +nadgrids= BUT Notice the ellipsoid a and b

Re: [Qgis-user] NTV2 Grid Shits

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Re: [Qgis-user] NTV2 Grid Shits

Last I checked QGIS 2.14 ignored any +geoidgrid= But it works fine in various stand alone Proj4 tools. Alternatively, any nadgrids and any geoidgrids files will open in QGIS as raster grids, so you can use them that way too. For example A gsb file will be multi band, latitude shift, longitude

Re: [Qgis-user] NTV2 Grid Shits

Dear Tyler! proj4 projections definitions are stored on ubuntu in the file /usr/share/proj/epsg, edit this file to add +geoidgrids=your_grid. QGIS projection definitions are stored in a sqlite database, on ubuntu you can find the srs.db in the /usr/share/qgis/resources directory. You can

Re: [Qgis-user] NTV2 Grid Shits

Since you guys both know more about PROJ4 than I do I thought I would just tag this question on; Where is QGIS/PROJ4 with support for vertical datums? Is there a way I can attach a vertical datum to a CRS in PROJ4? Tyler On Mon, Oct 23, 2017 at 9:09 AM, Tyler Veinot

Re: [Qgis-user] NTV2 Grid Shits

Am 20.10.2017 um 14:31 schrieb Tyler Veinot: Anyone knowledge in using grid shift files (gsb) with QGIS? I have a local CRS NAD27 Double Stereographic Imperial that I need to transform to NAD83 CSRS 2010 Epoch. I have the CRS properly defined using the provincial description Can you add your