[mapguide-users] BC Albers Projection

[Paul Ramsey]

The official EPSG number for BC Albers is 3005.  You might find you  
can simply use that number.
If you have to hand add it, find the "epsg" file in your installation  
and edit it and add a line like this:

<3005> +proj=aea +lat_1=50.0 +lat_2=58.5 +lat_0=45.0 +lon_0=-126.0  
+x_0=1000000.0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs  <>

And yes, adding it manually to the epsg file should work  
automagically. (No re-start required, etc.)

(Interesting FYI to the developers: we had a very very large UMN  
Mapserver .map file and we found that with our projections defined as  
EPSG numbers an astounding amount of time servicing each request was  
being spent opening and scanning through the epsg file.  So much so  
that changing the references from epsg numbers to full proj strings  
(thereby removing the need for a file lookup) substantially affected  
service performance.)

On 12-May-06, at 3:33 PM, Kori Maleski wrote:

> Here is the BC Albers:
>
> British Columbia Albers Standard Projection
> In 1994, the MSRM GIS Working Group chose a standard projection and  
> datum for all spatial data stored in ARC/INFO.
> The projection is Albers Equal Area Conic, with parameters of :
> Central meridian: -126.0 (126:00:00 West longitude)
> Latitude of projection origin: 45.0 (45:00:00 North latitude)
> First standard parallel: 50.0 (50:00:00 North latitude)
> Second standard parallel: 58.5 (58:30:00 North latitude)
> False easting: 1000000.0 (one million metres)
> False northing: 0.0
>
>
> I think the EPSG goes like this:
>
> # British Columbia Albers Standard Projection
> <9822> +proj=aea +lat_1=50.0 +lat_2=58.5 +lat_0=45.0 +lon_0=-126.0  
> +x_0=1000000.0 +y_0=0 +ellps=GRS80 +datum=NAD83 +units=m +no_defs  <>
>
>
> Not sure how to add it to the projection database.If you open up  
> the epsg file in the NAD directory with notepad you could just add  
> manually.  Not sure whether it will work...
>
>
>
>
>
> Kori Maleski  BSc.
> Senior Technical Consultant
>
> Pacific Alliance Technologies
> Suite 400 - 534 17 Ave. SW Calgary, AB CANADA T2S 0B1
> TEL 403.770.1917 FAX 877.691.9149 TOL 877.691.9171 www.pat.ca  
> <http://www.pat.ca/>
>
> ________________________________
>
> From: Joy Appler [mailto:jappler at my.bcit.ca]
> Sent: Fri 12/05/2006 2:48 PM
> To: users at mapguide.osgeo.org
> Subject: [mapguide-users] BC Albers Projection
>
>
>
> Has anyone defined a BC Albers map projection yet, or have any tips on
> how to modify the epsg file to add it?
>
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