[postgis-users] Create spatial_ref_sys entry from srtext ?

[Nicolas Ribot]

> Hi list !
>
> I received a bunch of shapefiles with a .prj file.
> I can't find the projection in the spatial_ref_sys table (it looks
> quite strange, it says "IGNBelg_Lam72").
> How can I insert a record for this projection in the
> spatial_ref_sys table ?
>
> Here is the .prj file content :
> PROJCS["IGNBelg_Lam72",
>     GEOGCS["Hayford 1924",
>       DATUM["<custom>",
>           SPHEROID["International_1924",6378388.0,297.0]
>         ],
>         PRIMEM["Greenwich",0.0],
>         UNIT["Degree",0.0174532925199433]
>     ],
>     PROJECTION["Lambert_Conformal_Conic"],
>     PARAMETER["False_Easting",150000.013],
>     PARAMETER["False_Northing",5400088.438],
>     PARAMETER["Central_Meridian",4.367486666667],
>     PARAMETER["Standard_Parallel_1",49.83333389],
>     PARAMETER["Standard_Parallel_2",51.16666729],
>     PARAMETER["Scale_Factor",1.0],
>     PARAMETER["Latitude_Of_Origin",90.0],
>     UNIT["Meter",1.0]
>    ]
>
>

Hi Arnaud,
You will have to find proj4 parameters (or infer them from the
parameters given in the .prj) for this new Spatial Reference System,
as Postgis uses proj4 to perform transformations.

After that, you can prepare an insert command, giving the proj4
parameters string, the SRTEXT, a new SRID (taken from the range of
public EPSG codes, for instance), and an authority id (the
organisation that gave you the projection, for example)

Nicolas