[GRASS5] Branching for 5.0.0 ahead

[Glynn Clements]

rgrmill at rt66.com wrote:

> > > The proj library is updated in everything but the make process, which I 
> > > think is in Glynn's capable hands.
> > 
> > It should be done, in that the .lla files are being compiled and
> > stored in $GISBASE/etc/nad.
> > 
> > A couple of issues:
> > 
> > 1. Should the ntv1_can.dat file be copied to $GISBASE/etc/nad also?
> 
> Yes.  That file is necessary for conversions in Newfoundland and in most 
> of Canada north of 50 degrees N; it is the preferred data for any 
> location in Canada.  The modules aren't currently using that grid, but 
> the proj library can use it and I expect the modules will be updated to 
> use it in the near future.

I've updated the Gmakefile to copy that file.

> > 2. What's the situation with the two-letter files (FL.lla etc)? 
> > According to nad/README (in proj-4.4.5), these are NAD83->NAD83,
> > whereas the others (e.g. conus.lla) are NAD27->NAD83. Are they meant
> > to be applied as a "correction" after NAD27->NAD83 conversion?
> 
> I think these should also be included to make the installation complete, 
> but if there is some problem then they can be omitted.  The two-letter 
> files provide grid conversions with more precision than is available 
> from the normal grids.  The modules don't currently use the high 
> precision files and I don't expect that the modules will use them until 
> there is some way of offering them to US users without also complicating 
> things for non-US users.

OK. They are being compiled and installed; I just wanted to check that
they were meant to get the same treatment as the other files.

-- 
Glynn Clements <glynn.clements at virgin.net>