
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div dir="ltr"><meta http-equiv="content-type" content="text/html; charset=utf-8"><div dir="ltr">Hi,</div><div dir="ltr">You probably found this but I am posting anyways in case you did not</div><div dir="ltr"><br></div><div dir="ltr"><a href="http://www.naref.org/transf/nad83_hydroscan2006.pdf">http://www.naref.org/transf/nad83_hydroscan2006.pdf</a></div></div><meta http-equiv="content-type" content="text/html; charset=utf-8"><div dir="ltr"><div dir="ltr"></div><div dir="ltr"><br></div><div dir="ltr"><a href="https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ntv2.php?locale=en">https://webapp.geod.nrcan.gc.ca/geod/tools-outils/ntv2.php?locale=en</a></div><div dir="ltr"><br></div><div dir="ltr"><a href="https://www.nrcan.gc.ca/maps-tools-and-publications/tools/geodetic-reference-systems-tools/tools-applications/10925#Epochs">https://www.nrcan.gc.ca/maps-tools-and-publications/tools/geodetic-reference-systems-tools/tools-applications/10925#Epochs</a></div><div dir="ltr"><br></div><div dir="ltr">Look for Trx and NTv2 tools.</div><div dir="ltr"><br></div><div dir="ltr">Nicolas</div><div dir="ltr"><br></div><div dir="ltr"><br></div><div dir="ltr"><br><blockquote type="cite">Le 22 nov. 2019 à 17:41, mhw-at-yg <matt.wilkie@gov.yk.ca> a écrit :<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><span>Hello,</span><br><span></span><br><span>Within the Yukon and NWT (Canada), how do you convert spatial data</span><br><span>horizontal datum from NAD83-Original (circa 1994) to NAD83-CSRS (2002+)?</span><br><span></span><br><span>I’ve been up and down NRCAN’s geodetic reference site[0] and a bunch of</span><br><span>other ones and am more confused than when I started. The consensus on the</span><br><span>net seems to be to use NTv2 to migrate from Original to CSRS, but there are</span><br><span>no grid shift files for the territories [1],[2].</span><br><span></span><br><span>Esri (ArcGIS Desktop) and Safe (FME) use transforms which are a null</span><br><span>operation, all that happens is a change in the name, the coordinates are</span><br><span>left unaltered. However looking at the v7 velocity grid[3] it looks like</span><br><span>there have been significant shifts since the 1990s.</span><br><span></span><br><span>Most of our new data acquisitions from survey and LiDAR are coming in as</span><br><span>CSRS. When combining with our old data and project-on-the-fly I’ve observed</span><br><span>different coordinates for the same points depending on how the locations are</span><br><span>reported. So we need to bring our holdings into a common coordinate system</span><br><span>to be assured our analyses are the most correct they can be, but how?</span><br><span></span><br><span>[0]:</span><br><span>https://www.nrcan.gc.ca/maps-tools-and-publications/tools/geodetic-reference-systems/18766</span><br><span>[1]: https://webapp.geod.nrcan.gc.ca/geod/tools-outils/grids.php (List)</span><br><span>[2]: https://webapp.geod.nrcan.gc.ca/geod/data-donnees/transformations.php</span><br><span>(Download, sign in but free account)</span><br><span>[3]: https://webapp.geod.nrcan.gc.ca/geod/tools-outils/nad83-docs.php</span><br><span></span><br><span>Thanks in advance for your advice,</span><br><span></span><br><span>Matt Wilkie</span><br><span>Geomatics Analyst</span><br><span>Environment | Information Management & Technology</span><br><span>T 867-667-8133 | Yukon.ca</span><br><span></span><br><span></span><br><span></span><br><span></span><br><span>-----</span><br><span>-Matt</span><br><span>--</span><br><span>Sent from: http://osgeo-org.1560.x6.nabble.com/PROJ-4-f3840930.html</span><br><span>_______________________________________________</span><br><span>PROJ mailing list</span><br><span>PROJ@lists.osgeo.org</span><br><span>https://lists.osgeo.org/mailman/listinfo/proj</span><br></div></blockquote></div></div></body></html>