[postgis-users] transform() does not do work for NGO1948 zone III-> WGS84 longlat (epsg:27393->epsg:4326)

[strk at refractions.net]

mmm... I checked using transform_geometry() to exclude
the new proj4 caching code... It still gives the same
result:


strk=# select astext(transform('SRID=27393;POINT(2836.394208896 185526.991186176)',4326));
                   astext
--------------------------------------------
 POINT(0.0464201635443672 59.6661916850467)
(1 row)

strk=# select astext(transform_geometry('SRID=27393;POINT(2836.394208896 185526.991186176)', get_proj4_from_srid(27393), get_proj4_from_srid(4326), 4326));
                   astext
--------------------------------------------
 POINT(0.0464201635443672 59.6661916850467)
(1 row)

This is with  Rel. 4.4.8, 3 May 2004, PostGIS 1.1.0.

PROJ4 text for 27393 is as follows:

 +proj=tmerc +lat_0=58 +lon_0=-10.72291666666667 +k=1.000000 +x_0=0 +y_0=0 +a=6377492.018 +b=6356173.508712696 +towgs84=278.3,93,474.5,7.889,0.05,-6.61,6.21 +pm=oslo +units=m +no_defs

PROJ4 text for 4326 is as follows:

 +proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs

This is both in the db and in the spatial_ref_sys.sql script in 1.1.0.

Can you check corrispondent values in your old *working* setup ?

--strk;

On Thu, Dec 22, 2005 at 01:07:17PM +0100, Havard Tveite wrote:
> It is nice to provide warnings, but for epsg:27393 -> epsg:4326
> the following problems persist:
> 
> 1) Longitude of origin (+lon_0=-10.72291666666667) is ignored
>    (as demonstrated by strk's query).
> 2) No datum shift seems to be performed.
> 
> Since the transformation runs smoothly using UMN Mapserver (
> with dynamically linked proj - so it should be 4.4.9), there
> is probably a problem somewhere.
> 
> 
> I have an old PostGIS running (0.8 over 7.4.1 - proj statically
> linked "old" version), and for that setup, the transformation
> seems to be OK (including datum shift).
> 
> select AsText(
> transform('SRID=27393;POINT(2836.394208896 185526.991186176)',4326)
> );
> >  POINT(10.7732463298862 59.665688397594)
> 
> 
> Håvard