Canadian Transformation GSB Files

[Pointdump]

In C:\ProgramData\Autodesk\GeospatialCoordinateSystems 14.10\Canada there is a ReadMe.txt file, which has been there in every version I can remember back to at least 2016. Attached.
"This text file discusses issues concerning geodetic grid interpolation data files which are supported by Autodesk products, but which are not distributed with Autodesk products."
I can find no information on exactly which files need to go where in MAPCSLIBRARY.
We'll start with a drawing assigned NS.ATS77.MTM-5 coordinate system. In MAPCSLIBRARY it shows that CS uses the NS.ATS77 Datum.
Searching NS.ATS77 in MAPCSLIBRARY checking boxes for Datum, Geodetic Transformation, and Geodetic Transformation Path produces this:

C3D and M3D seem to require a Geodetic Transformation to WGS84 to work, so sure enough there's a Geodetic Transformation Path listed for NS.ATS77_to_WGS84:

Let's look at all 4 Geodetic Transformations listed there. First on the list is NS.ATS77_to_NS.NAD83.2010. There are 3 ways to transform between datums, but the only one not greyed out is "-Grid Data File Interpolation". It's empty. Which means there is a null transformation:

If you go to >>>NRCAN<<<(requires creating a free account) and scroll down to Nova Scotia they have 2 available GSB files:

Next is NS.NAD83.2010_to_CSRS.2010. All 3 methods of Geodetic Transformation are greyed out and the Edit Button is also greyed out, so there is no way to further define this.

Next is CSRS_to_CSRS.2010. Empty.

Last one is WGS84_to_CSRS. All 3 methods are greyed out. And no Edit Button:

It would be nice to have more information on this from Autodesk.
Dave

[Kyle-Evans]

Basically at it's essence, the Government of Canada does not allow Autodesk to supply the required .GSB file. I do not know why, I just know that I have been dealing with this for many many many... years. It is rather annoying that every version I need to supply the file (willingly provided by the Government) and map it into my Civil 3D.

https://open.canada.ca/data/en/dataset/b3534942-31ea-59cf-bcc3-f8dc4875081a

You can hopefully find the NTV_2.0.GSB file at the above link, as I am not sure I can even upload it to the forums. 

Under Map CS Library, I have to manually add it to the NAD83_to_SCRS library. 

[Pointdump]

Hi Kyle,
"...does not allow Autodesk to supply the required .GSB file."
Yup, I've read about that many times. And each year I keep hoping that maybe they'll either install the files or tell how to use the province specific files. Both the Autodesk page and your link are exasperatingly deficient in information. Both pages talk about "...a shift between the NAD27 and NAD83 datums." "Binary Grid Shift File (.GSB format) to transform coordinates between the NAD27 and NAD83 reference systems..."
Neither Autodesk nor NRCan will explicitly name the epoch. I'm assuming it's NAD83(86), but is it the US or the CSRS version? Isn't that what it's supposed to be about? And unless I have data or drawing in NAD27, why would this be used at all?
All the provinces have specific GSB files, and I've used them. They looked OK, but I really would like something definitive. NRCan has online and standalone versions of TRX transformations, but I can't find any solid metadata on control point coords to test.
Dave

[Kyle-Evans]

I have found the NTV_2.0.GSB file covers everything that I need. It includes provincial-specific items and NAD 27 shenanigans. I will see if I can track down an actual download link from the Canada webpage.

From what I remember, when I last looked into this 5-6 years ago it was hidden behind 5-10 different weblinks and a NRCAN account. 

[Kyle-Evans]

Here is a link I created to a Youtube video years ago...

https://youtu.be/gjS__MAugt0?si=djQ13z3z_9RGivc9&t=171 

I also have this comment as NRCAN moved the file after I made the video.

Instead of Clicking on the Help for NTv2, click on the coordinate transformation page just above it. On the next page that loads, scroll down a touch and under Horizontal 2D Transformations expand National. Then you can click on Download NTV2_0.GSB. You will need to make an account with the Government of Canada in order to access this file.

[Kyle-Evans]

Found it!!

https://webapp.csrs-scrs.nrcan-rncan.gc.ca/geod/account-compte/login.php

If you go to this webpage, create an account and sign in. You can scroll down to Horizontal (2D Transformations) and download the entire countries .GSB files. It looks like most/if not all of the provinces are included.

As for how to set them all up inside of Civil 3D, that would require a lot more digging I assume. My video link basically shows what I need and what I use. 

[Pointdump]

Kyle,
Yup, I included that link in my 1st post.
"...all of the provinces are included. As for how to set them all up inside of Civil 3D, that would require a lot more digging I assume."
This is EXACTLY the question I'm asking. I can GUESS how to use the province-specific files, but I'd rather KNOW how to use them.
Dave