[GRASS-user] projection for northern europe

[Craig Leat]

Maciej Sieczka <tutey at o2.pl> wrote:
> Date: Tue, 16 Oct 2007 21:59:30 +0200
> From: Maciej Sieczka <tutey at o2.pl>
> Subject: Re: [GRASS-user] projection for northern europe
> To: Maciej Tomaszczyk <mtom at pgi.gov.pl>
> Cc: grassuser at grass.itc.it
> Message-ID: <47151822.2010600 at o2.pl>
> Content-Type: text/plain; charset=ISO-8859-2
>
> Maciej Tomaszczyk wrote:
> > > hello 
> > > I prepared a map of northern europe in Lat/lon location, now i would like to reproject
> > > it to location with meters unit so my question is, what is the best projection for this
> > > area (baltic sea area).
>
> Hi Maciej
>
> The recently deployed EPSG Geodetic Parameter Registry site
> [1] might be usefull when searching for hints in such cases.
>
> AFAIK for pan-European mapping the ETRS-LAEA (EPSG 3035) and
> ETRS-LCC (EPSG 3034) are often used.
>
> Or try asking on PROJ.4 list?
>
> [1]http://www.epsg-registry.org/
>
>   

Hi Maciej

AFAIK, ETRS89 / ETRS-LCC (EPSG 3034) is the Lambert Conformal Conic 
projection using the European Terrestrial Reference System (1989) 
ellipsoid. This is a conformal projection, so shape is preserved and the 
maps "look right".

ETRS89 / ETRS-LAEA (EPSG 3035) is the Lambert Azimuthal Equal-Area 
Projection, also using the European Terrestrial Reference System (1989) 
ellipsoid. As the name suggests this projection preserves area at the 
expense of shape and distance.

Which projection you choose to use should be determined by the purpose 
of your map. Do you want the shape of the countries to look right or do 
you want to calculate areas (or measure distance for that matter)? 
Remember to check that your current geographic (LatLon) coordinate 
system is using the same ellipsoid as your target projected coordinate 
system.

Regards

Craig Leat.