[Proj] Proj 4.9.3RC1 Released
sebastic at xs4all.nl
Wed Aug 17 03:04:17 EST 2016
On 08/17/16 04:35, Howard Butler wrote:
>> On Aug 16, 2016, at 2:48 AM, Sebastiaan Couwenberg <sebastic at xs4all.nl> wrote:
>> May I also request that proj-datumgrid-1.6RC1  is promoted to final
>> along with the last proj-4.9.3RC?
> We can promote it, but surely there have been updates since 2012? I unfortunately do not know how this was produced, and I don't know how to refresh it with current grid files. Frank's original message pointing to it from April 2012 is here .
>  http://osgeo-org.1560.x6.nabble.com/Datum-Grid-Files-td4900930.html
proj-datumgrid-1.6RC1 is already three years more recent than 1.5 that
most distributions are still using, so that upgrade is already very welcome.
Hopefully Frank will be able to clarify the process to create the
proj-datumgrid distributions, or someone will need to reverse engineer it.
I guess the process involves using nad2bin from proj >= 4.8 to convert
the .lla source to the ctable2 output format.
For the content of the files you probably need the government
organisations of the countries in question that provide the source data,
as a Dutchman I'm not too familiar with those for US/Canada/France/New
Zealand. For the latter two I investigated the origin of their
respective .gsb files as part of the discussion with the Dutch Kadaster
when they published their grid shift files for The Netherlands
specifically for PROJ.4.
The French grid is derived from public data, see:
The New Zealand data should be public too, and probably originates from:
>> No issues have been reported with the proj-datumgrid-1.5 upgrade to
>> proj-datumgrid-1.6RC1 in the Debian package which has been available for
>> some time now, and included in Ubuntu since wily. I don't think there
>> are any blockers to promoting proj-datumgrid-1.6RC1 to final.
> I'm happy to simply promote it, but is there is value in bringing it forward to 1.7 and including any updated grids? It will probably be another year before we have a proj.4 release unless some critical thing shows up, so it would be best to knock these things out while there's attention.
Let's first make 1.6RC1 one final, before worrying about 1.7. It's worth
investigating whether the data for the US has changed or if the .lla
files from 1.5 were used to create the ctable2 format binary files in
1.6RC1 (which I suspect is the case).
For the long term viability of proj-datumgrid getting a more formal
release process is a good thing. That includes documenting where the
data comes from and how to update it.
The number of countries supported by proj-datumgrid is very limited, for
every other country users need to obtain the grid shift files themselves
(although I've packaged the Dutch grid shift files for Debian), e.g.
using the links from the Grids documentation page:
An argument could be made to just drop the proj-datumgrid distribution
and leave it up to users to obtain the data files. But I suspect the
effort involved getting the data was the reason to bundle them in
proj-datumgrids to save others that pain.
GPG Key ID: 4096R/6750F10AE88D4AF1
Fingerprint: 8182 DE41 7056 408D 6146 50D1 6750 F10A E88D 4AF1
More information about the Proj