[postgis-users] spatial_ref_sys

[Jürgen Mischker]

I found some wrong lat_0 parameters in proj4text fields:
The affected projections are for (tiny) Austria and have the srids: 31281, 31282, 31283, 31288 - 31293

an example, srid 31281 (Austrian West Zone):

proj4text:
=+proj=tmerc +lat_0=0 +lon_0=45.6666666666666 +k=1 +x_0=0 +y_0=0 +ellps=bessel +pm=ferro +units=m +no_defs
The Primary Meridian (+pm) was set to "ferro" but the lat_0 parameter to 45.6... which would be the value for Greenwich, the right value would be 28 (45°40' - 17°40'). The srtext field is correct "...PARAMETER["central_meridian",28]..."
Same thing for the other 2 meridians M31 and M34.

Also a good thing would be to add projection definitions for all three meridians (M28, M31, M34) with a false_northing value of -5000000 (a very common thing here;-) )

Thanks to Franz Suppan for his redemptive help...

Jürgen

DDI Jürgen Mischker
Insitut f. Vermessung, Fernerkundung und Landinformation,
Universität für Bodenkultur, BOKU, Wien
Institute of Surveying, Remote Sensing and Land Information.
University of Natural Resources and Applied Life Science, Vienna.
Tel.: +43 1 47654-5132
Fax.: +43 1 47654-5142
email: jmischker at boku.ac.at