5.6.2+
You may select a Projection for your Map Source by picking an entry from the list. There is a default Projection that is configured via the iShare Settings on the General tab under the Web heading.
In previous versions of iShare the .map file points to the Projections supplied by MapServer which contains a long list of SRID without any descriptions. Astun now supply a cut down Projection file in a projections folder that will not be overwritten if MapServer is upgraded e.g. D:\iShareData\Astun\_MapServerConfig\projections\epsg
Configure your .MAP file to use the new Projections file
If you wish to use this file instead of the default MapServer projection file you will need to edit your .map file to point to the new projections file by changing the CONFIG "PROJ_LIB" entry e.g.
CONFIG "PROJ_LIB" "projections"
Adding your own Projections
You may add your own Projections by opening the file in a Text Editor such as Notepad++. The entries must be formatted correctly to display in the list correctly e.g. for BNG
# OSGB 1936 / British National Grid <27700> +title=British National Grid +proj=tmerc +lat_0=49 +lon_0=-2 +k=0.999601 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs no_defs <>
The first line is just a comment the next has the following formatting requirement:
| Code | Descrption |
|---|---|
<27700> | The SRID for the projection |
+title=British National Grid | The Title to display |
+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.999601 +x_0=400000 +y_0=-100000 +ellps=airy +units=m +no_defs no_defs | The Projection definition. In order to find the correct definition for your required projection please see http://spatialreference.org/ref/ select the relevant entry and then click on the Proj4 link which will give you what you require. |
| <> | The end of line |