[mapserver-users] changing projection

[Paul Spencer]

You will need to specify the projection of the source data in each of  
the layers and then specify the output projection you wish to have at  
the map level and mapserver will reproject your data on the fly.

Note that you need to set your extent and units at the map level  
appropriately to the output projection.  For instance, if your source  
data is in lat/lon (decimal degrees) you would be using UNITS DD but  
if you change to output the projection below, you would need to change  
to UNITS METERS

Cheers

Paul

On 15-Jul-08, at 6:36 PM, boice tomlin wrote:

>
> Hello,
>
> We are using mapserver version 4.10 and in our mapfile we don't  
> specify a projection at the map level or in any of the layers.
>
> Now we need to change the projection to;
>
> North_America_Albers_Equal_Area_Conic projection
>
> I have added the following projection information to the map file  
> but it does not effect our map at all.
>
> PROJECTION
>     "+proj=aea +lat_1=20 +lat_2=60 +lat_0=40 +lon_0=-96 +x_0=0  
> +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs"
> END
>
> I'm assuming there are some other things we need to do besides  
> specifying the projection in the mapfile.  Can anyone provide me the  
> appropriate steps?
>
> We are using PHP Mapscript and shape file from the US census.
>
> Should we expect to be able to change projections on the fly by  
> specifying the projection we want to use in the mapfile?
>
> thank you for the information.
>
> -boice
>
>
>
>
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users


__________________________________________

    Paul Spencer
    Chief Technology Officer
    DM Solutions Group Inc
    http://www.dmsolutions.ca/