Hi folks...
hat's my first mail, thanks for grass.
I'm from Chile, South America. Here we use PSAD-56 datum,
international ellipsoid from 1909 (1924).
I have the Molodensky constant for PSAD-56 datum (dx, dy and
dz). I have semiaxes values too.
I wnat to lnow how can i add this datum to the list. i had
added to /usr/local/grass5/etc/datum.table, but didn't appear
when i enter the location projection...
So, how can i do it?
Thanks.
Mauricio Vargas P.
Geólogo
MsC en Geología
Usurio Linux # 326558 counter.li.org
PS: Sorry for my english, i'm not native english speaker
On Mon, 22 Mar 2004, Mauricio Vargas P. wrote:
Hi folks...
hat's my first mail, thanks for grass.
I'm from Chile, South America. Here we use PSAD-56 datum,
international ellipsoid from 1909 (1924).
I have the Molodensky constant for PSAD-56 datum (dx, dy and
dz). I have semiaxes values too.
I wnat to lnow how can i add this datum to the list. i had
added to /usr/local/grass5/etc/datum.table, but didn't appear
when i enter the location projection...
It should; how exactly did you add it?
On Tue, 23 Mar 2004, Mauricio Vargas P. wrote:
On Tue, 23 Mar 2004 08:27:31 +0000 (GMT), Paul Kelly wrote
> It should; how exactly did you add it?
I just added it. A first line with a comentary (#blablabla),
and a second line with the paremeters...
I mean what is the line you added! And a more detailed description
of the problem (assuming you want somebody here to try and do something
about it 
)
On Tue, 23 Mar 2004, Mauricio Vargas P. wrote:
On Tue, 23 Mar 2004 14:51:26 +0000 (GMT), Paul Kelly wrote
> I mean what is the line you added! And a more detailed
> description of the problem (assuming you want somebody
> here to try and do something about it )
ok
this are the lines i added to datum.table...
# South American 1956, PSAD-56, elipsoid: international 1924
(1909)
PSAD-56 "Sudamericano 56" int1924(1909) dx=-288 dy=175 dz=-376
OK. The ellipsoid int1924(1909) doesn't exist in GRASS so you would also
need to add it to ellipse.table (in the same directory as datum.table).
However I suspect it is the same as GRASS' international ellipsoid, in
which case if you replace 'int1924(1909)' by 'international' it should
work and g.setproj will correctly prompt you for this datum (no
modifications to ellipse.table needed).
Also note that for maximum compatibility with other GIS (relevant only
when exporting projection information from GRASS 5.7) the second item
(the datum long name) should be the EPSG standard name for the datum. This
usually has spaces converted to underscores in it so the above looks wrong
to me. However it is not that important.
Paul