Hello Daniel
I just downloaded the NTV2_0.gsb file from the webapp.geod.nrcan.gc.ca
web site and tried to transform the "NAD27 input" point. I got the
following result, which seem to match the expected result. No warning
was reported during my test.
Expected: 51.325841, -115.15486299
Actual: 51.32584099858066 -115.1548629958289
Maybe the NTV2 file has been altered during the transfer? What is the
output of "md5sum NTV2_0.gsb" on your file? In my case I get the following:
f91da910eb02304456c2f7372a596ead NTV2_0.gsb
Also which version of SIS is used, and is the system a Windows, Linus or
MacOS system?
Martin
Le 03/12/2021 à 23:02, Daniel E Harter a écrit :
I downloaded NTV2_0.GSB grid file from the Canadian Government
site[1]. It is used in the transformations EPSG:1313 NAD27 to NAD83
(4) and EPSG:1693 NAD27 to WGS 84 (33). When I try to use either
transform, I get the following in the console:
Dec 03, 2021 1:38:43 PM
org.apache.sis.internal.referencing.provider.NTv2 createMathTransform
WARNING: Loading of “NTv2_0.gsb” done, but some records were ignored
because of unrecognized keywords: DATUM_F, DATUM_T
NAD27 input: (51.325795, -115.15383774, NaN)
Transform EPSG:1313 NAD83 result: (51.325853158412635,
-115.15382696154606, NaN)
Transform EPSG:1693 WGS84 result: (51.325853158412635,
-115.15382696154606, NaN)
Expected result From Canada NTv2 webapp: (51.325841, -115.15486299, NaN)
