[GRASS5] problems with [rsv].proj

GRASS GRASS developer
1

Bernhard wrote:

On Thu, May 30, 2002 at 09:26:50AM -0400, Frank Warmerdam wrote:

Hopefully this can be properly incorporated into GRASS in 5.1. I
was a bit weirded out that datum shifting was grafted into GRASS late in the
pre-release countdown sequence.

Yes, it was a mistake.

Making the changes was not a mistake. The mistake was in not making the changes months ago.

GRASS5.0.0 stable will be of relatively little use in the US if it were released without the ability to perform the nad27<->nad83 datum shifts. The situation is made even worse because the projection and region information provided by GRASS makes it appear that datum conversions are done.

Markus agreed about a year ago (May 27, 2001, to be exact) that datum conversions should be included in 5.0.0stable before it is released.

GRASS5.0.0 probably should support datum changes other than nad27<->nad83. That is a very fundamental capability.

Roger Miller

2

On Thu, May 30, 2002 at 03:16:31PM -0400, rgrmill wrote:
[...]

GRASS5.0.0 probably should support datum changes other than nad27<->nad83.
That is a very fundamental capability.

Apart from the discussion when to submit datum support: I agree that
GRASS should *as soon as possible* (whatever that means) support
datum changes other than nad27<->nad83.

Find attached an ongoing small test with northern Italian sample
coordinates. The datum support already present in PROJ4 improves
the result significantly (from 25m E-W and 70m N-S shifts to 2m E-W
and 9m N-S using the cs2cs program with datum).

Find attached preliminary results. I'll post the complete results later
in PROJ4 mailing list after receiving more known points for other
parts of Italy (is anyone there who can deliver this?).

Cheers

Markus

(attachments)

projection_povo_points_proj4res.txt (2.72 KB)