[postgis-users] Error in some reference systems in the table SPATIAL_REF_SYS

[Gino Lucrezi]

Hi!

I use postgis 8.1, with the proj4 library Rel. 4.4.8, dated 3 May 2004 

I know postgis 8.2 is already out, I'll install it soon, but I see that this table hasn't changed, either in 8.2 or in the CVS version.

I think my version of Proj4 it's the latest version, too, but today their web site is down so I can't check it).

Anyway, the entries in the table SPATIAL_REF_SYS for the Gauss-Boaga system, widely used in Italy, are incorrect. If I try to transform some data from another system into Gauss-Boaga, the results for longitude are wrong.

Browsing in the archives of the proj4 support list I could see that there is a problem in the entries. The pm (Prime Meridian) attribute is not needed, and it is a cause of error.
If I remove it, transforms are correct.

Here are the corrected entries for spatial_ref_sys.sql:

INSERT INTO "spatial_ref_sys" (srid, auth_name, auth_srid, srtext, proj4text) VALUES (26591,'EPSG',26591,'PROJCS["Monte_Mario_Rome_Italy_1",GEOGCS["GCS_Monte_Mario_Rome",DATUM["D_Monte_Mario",SPHEROID["International_1924",6378388,297]],,UNIT["Degree",0.017453292519943295]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",1500000],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",-3.45233333],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0],UNIT["Meter",1]]','+proj=tmerc +lat_0=0 +lon_0=9.00000000333333 +k=0.999600 +x_0=1500000 +y_0=0 +ellps=intl +units=m');

INSERT INTO "spatial_ref_sys" (srid, auth_name, auth_srid, srtext, proj4text) VALUES (26592,'EPSG',26592,'PROJCS["Monte_Mario_Rome_Italy_2",GEOGCS["GCS_Monte_Mario_Rome",DATUM["D_Monte_Mario",SPHEROID["International_1924",6378388,297]],,UNIT["Degree",0.017453292519943295]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",2520000],PARAMETER["False_Northing",0],PARAMETER["Central_Meridian",2.54766667],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0],UNIT["Meter",1]]','+proj=tmerc +lat_0=0 +lon_0=15.00000000333333 +k=0.999600 +x_0=2520000 +y_0=0 +ellps=intl +units=m');


Thank you to all PostGIS developers for their efforts!

Gino Lucrezi
Penta Consulting Services Srl