Hi Martin,

The problem turned out to be that I was using version 1.0 instead of 1.1. Once 
I updated my pom the warning message went away, and I got the correct result.

Thank you.

Daniel

From: Martin Desruisseaux <[email protected]>
Sent: Friday, December 3, 2021 4:59 PM
To: [email protected]
Subject: Re: NTv2 Canada file

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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)

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