Re: [PanoTools-devel] Equirectangular Projection and new projections

[Erik K. <eri...@gm...>]

On Monday, December 11, 2006 at 9:52, Daniel M. German wrote:

> I was learning this morning about map projections and I read that
> equirectangular projections has a variable parameter called the
> "standard parallel". 
> 
> >>From the wikipedia:
> 
> (\lamba, \theta) -> (\lamba * cos (\theta_1), \theta)
> 
> \theta_1 is the standard parallel. 
> 
> Is \theta_1 =3D=3D 0 in hugin/panotools/nona?

Yes, as far as I understand it. They say: "\phi_1 are the standard 
parallels (north and south of the equator) where the scale of the 
projection is true."

In map projections scale is an important factor, since if the scale 
is true you can measure distances easily. For our equirect projection 
(what they call "plate carr=E9e") with 2:1 aspect ratio scale is only 
true horizontally along the equator and vertically. 

best regards
-- 
Erik Krause
Resources, not only for panorama creation: 
http://www.erik-krause.de/