Plate Carre with latitude shift

[Frank Warmerdam]

Espen Isaksen wrote:
> Ok, I set my mapfile like this:
> 
> EXTENT 10.6661 59.9155 10.6824 59.9214
> PROJECTION
>     "+proj=eqc +lat_ts=60 +lon_0=0 +x_0=0 +y_0=0 +datum=WGS84"
> END
> 
> and this is what I have had before:
> 
> EXTENT 10.6661 59.9155 10.6824 59.9214
> PROJECTION
>     "init=EPSG:4326"
> END
> 
>>From my understanding the former mapfile should give the same map as
> the latter, but the east-west coordinates should be pushed together as
> this formula would indicate: x=lon*cos(lat) where lat is 60 and the
> formula then gives x=lon*0.5?
> 
> All I get is a blank map, so I suppose there is something I have misunderstood?

Espen,

EPSG:4326 is a geographic coordinate system, and the coordinates are in
decimal degrees.  +proj=eqc is a projected coordinate system and the
coordinates are meters.  The location (-180,90) would be roughly
(-20000000,100000).

Essentially eqc (ie. equidistant cylindrical or Plate Carree) is just
a rescaling of EPSG:4326 from degrees to meters.

I'm afraid I just don't get what you hope to accomplish with +lat_ts=60.
Are you hoping to get one projected meter being one meter on the ground
at 60N as opposed to it being one meter at the equator as is the default?
I'm not aware of proj=eqc supporting any such option.

Best regards,
-- 
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