[OpenLayers-Users] How to define a custom Proj4js.defs["myown"]?

[Mike Adair]

It should be something like:

+proj=stere +lat_0=90 +lat_ts=60 +lon_0=263 +k=??? +x_0=3450000 
+y_0=7450000 +ellps=WGS84 +datum=WGS84 +units=m

I'm not positive about the lon_0 param, and the k param is a ratio of 
resolution at standard parallel to another resolution value but I'm not 
sure what that other value is.  To test to see if the above works, set 
k=1.0 and we can look up what the correct value for K should be.

Mike Adair



stephane.poirier at usherbrooke.ca wrote:
> Hi All,
>  
> How to define a custom Proj4js.def["myown"] when it is not in 
> http://spatialreference.org/ref
> but when I have the following projection parameters?
>  
> lon_0??       > 
> polar_stereographic:straight_vertical_longitude_from_pole = 263.f ;
> lat_ts           > polar_stereographic:standard_parallel = 60.f ;
> x_0             > polar_stereographic:false_easting = 3450000.f ;
> y_0             > polar_stereographic:false_northing = 7450000.f ;
> lat_0           > polar_stereographic:latitude_of_projection_origin = 
> 90.f ;  
> proj=stere   > polar_stereographic:grid_mapping_name = 
> "polar_stereographic" ;
>                    > 
> polar_stereographic:resolution_at_standard_parallel = 50000.f ;
>  
> For example, using 
> http://spatialreference.org/ref/epsg/32661/proj4js/ for universal 
> polar stereographic (which is usefull when used for area above the 60 
> degrees north ), I get Proj4js.defs["EPSG:32661"] = "+proj=stere 
> +lat_0=90 +lat_ts=90 +lon_0=0 +k=0.994 +x_0=2000000 +y_0=2000000 
> +ellps=WGS84 +datum=WGS84 +units=m +no_defs";
>  
> Regards,
>  
> Stephane
>  
>  
> Stephane Poirier, M.Sc. Optics Physics
> Remote Sensing Research Professional
> University of Sherbrooke, QC, Canada
> Stephane.Poirier at USherbrooke.ca <mailto:Stephane.Poirier at USherbrooke.ca>
> http://www.usherbrooke.ca/cartel
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-- 
   Michael Adair
   Senior Software Architect
   DM Solutions Group Inc.

   Office: (613) 565-5056 x26
   madair at dmsolutions.ca
   http://www.dmsolutions.ca
   http://research.dmsolutions.ca