[gdal-dev] Required PROJ data in PROJ7

[John Daniel]

Hello,
The old proj-datumgrid is divided into a small, 13 MB required dataset and a number of much larger optional regional datasets. The new proj-data doesn't seem to have this distinction. It is smaller overall, but still 500 MB. 

I am interested in using GDAL in mobile apps so I don't want to include that much data. Is there a smaller set of proj-data files that can be used instead? Which of those files are required and which can be omitted? For example, it is possible to split the data by region, but with the software work with only a partial set of files? Can the data files be downloaded at runtime, on demand? If so, I'm sure I will need to include a few of them by default.

It looks like PROJ 7 can still be used with the old data. Is PROJ 7 safe for use with other projects? I have seen some messages that suggested that this was a problem for some projects. I think Spatialite was one. I won't be distributing with GPL projects like GEOS or Spatialite, but I would still like to use them for local testing.

Thanks.

John Daniel
Etresoft, Inc.