[Proj] PROJ 4.4.8 - Release Candidate

Frank Warmerdam warmerdam at pobox.com
Tue May 4 14:25:50 EDT 2004


Markus Neteler wrote:
> Frank,
> 
> thanks for the updates. However, the problem with prime meridian
> seems to be unsolved.
> 
> # LatLong to Italian Gauss Boaga Fuso Ovest (1st Zone):
> cs2cs -v +proj=latlong +datum=WGS84 +to +init=epsg:26591 \
>          +towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68
> 11d12'26E 46d06'17N 100
> -251428.83      5362296.50 54.97
> 
>  -> This result is wrong.
> 
> # Using the old method:
> cs2cs -v +proj=latlong +datum=WGS84 +to +proj=tmerc +lat_0=0 +lon_0=9 \
>        +k=0.999600 +x_0=1500000 +y_0=0 +ellps=intl +units=m \
>        +towgs84=-104.1,-49.1,-9.9,0.971,-2.917,0.714,-11.68 \
>        +no_defs
> 11d12'26E 46d06'17N 100
> 1670617.27      5108072.04 54.97
> 
>  -> This looks correct.
> 
> In my opinion the nad/epsg file entries for 26591 and 26592
> and maybe all others with +pm parameter are wrong (more than
> 60 projections). Or the prime meridian is not applied correctly.
> 
> Interesting: The lon_0 values seem to be correct in GDAL/gcs.csv
> 
> Probably I am missing something (please let me know),
>://www.remotesensing.org/mailman/listinfo/proj

Markus,

Now I remember why I put off dealing with this for so long.  There was
a tangle of problems and mistaken assumptions in the way I was processing
various longitudinal values relative to prime meridians through from the
EPSG to the PROJ.4.  I have corrected the code in GDAL/OGR used to generate
the epsg file, and issued a new PROJ 4.4.8 release with the corrected
epsg file.  The first example you gave now gives correct results.

Please verify as soon as you get a change.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent




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