I am looking to determine the correct Grid Shift Binary (gsb) file for transforming data from the NAD83 original to NAD83(CSRS) geodetic datum for the NWT in Canada. I was able to find reference for a NAD83-98.gsb file for this purpose for Quebec, and I believe I saw another for Ontario, and other provinces, but nothing for NWT.
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Would this one for entire Canada be useful for you? open.canada.ca/data/en/dataset/…– Hans ErrenCommented May 14, 2019 at 16:07
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1@HansErren reviving old comments on an old question, but I have some more insight on this now, and figured I'd share. The GSB file you link to here is for transforming from NAD 1927 to NAD 1983 (Original), using the NTv2 grid-shift transformation; not for a NAD 1983 (Original) to NAD 1983 (CSRS).– rgmrtnCommented Nov 20, 2019 at 15:13
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1 Answer
Unlike some other provinces (see list in answer comments). There is no specific transformation from NAD 1983(Original) to NAD 1983(CSRS) specific to the Northwest Territories, or to Canada as a whole. I have used the assumption that the differences between NAD 1983(Original) and NAD 1983(CSRS) are negligible (Figure 2.,Craymer, 2006) for specific areas.
Craymer, M. R. (2006). The evolution of nad83 in canada. GEOMATICA, 60(2), 151-164,433.
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The following is a list of province-specific NTv2 GSB files available. webapp.geod.nrcan.gc.ca/geod/tools-outils/…– rgmrtnCommented Nov 20, 2019 at 15:39
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The names in the list are useful but the links in the don't lead anywhere Commented Nov 20, 2019 at 23:32
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Thank you for the Geomatica article. The graphics for CSRS v7 at webapp.geod.nrcan.gc.ca/geod/tools-outils/nad83-docs.php indicate there are now more differences since NAD83-Original. That said I haven't found any resources yet for Original-to-CSRS in the North. Commented Nov 20, 2019 at 23:43
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@mattwilkie the list is for this tool webapp.geod.nrcan.gc.ca/geod/tools-outils/ntv2.php Thanks I should've added this.– rgmrtnCommented Nov 22, 2019 at 15:02
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1I fleshed out the info from these links into a general answer for most canadian CSRS questions at gis.stackexchange.com/questions/304398/…. Thanks rgmrtn. Commented Sep 23, 2020 at 19:20