Maciej Sieczka <[EMAIL PROTECTED]> wrote:
Date: Tue, 16 Oct 2007 21:59:30 +0200
From: Maciej Sieczka <[EMAIL PROTECTED]>
Subject: Re: [GRASS-user] projection for northern europe
To: Maciej Tomaszczyk <[EMAIL PROTECTED]>
Cc: grassuser@grass.itc.it
Message-ID: <[EMAIL PROTECTED]>
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.
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