[postgis-users] help creating srid for custom projection

[Paul Ramsey]

Mostly you need a valid proj4 definition. You can fill in the rest of 
the values almost anyway you want (as long as srid remains unique).

INSERT INTO spatial_ref_sys (srid, auth_name, auth_srid, proj4text) 
VALUES (500000,'BWOOD',500000,'+proj=merc +lat_ts=-41 +lon_0=100 
+k=1.000000 +x_0=0 +y_0=0 +ellps=WGS84 +units=m');

Paul

Wood Brent wrote:

> Hi,
> 
> I have data in a custom projection written into a postgis table from a
> shapefile.
> 
> I have a copy of some docs describibing srid's but am still not sure how to
> create an appropriate entry in tne spatial_ref_sys table that will allow me to
> reproject (transform) the data to lat/long to allow spatial queries/joins with
> my other lat/long datasets.
> 
> I have been told the supplied data coordinates are mercator northings &
> eastings in metres, using wgs84 spheroid, with a central meridian of 100E and
> latitude of true scale at 41S. There are no false northing/easting offsets.
> 
> Can someone suggest how this can be specified in the spatial_ref_sys table?
> 
> 
> Thanks
> 
>   Brent Wood
> 
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      | Paul Ramsey
      | Refractions Research
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