What geographic projection is used in GREAT-ER
jan at intevation.de
Thu Jun 12 12:47:31 CEST 2003
On Thu, Jun 12, 2003 at 11:30:09AM +0100, Johan Olanders wrote:
> I wonder what geographic projection is used in GREAT-ER.
GREAT-ER uses geographic coordinates as a basis.
This is acutally no projection but really the raw data.
Decimal degrees is the unit.
> I understand that I need to have the coordinates expressed as longitude and
> latitude in decimal degrees, but what geographic projection is used. The
> formula I'm planning to use for converting from UK national grid references
> to longitude latitude needs information such as:
Your GIS should be able to perform the transformation from UK National
Grid to geographic coordinates quite easily. I recommend not to
develop your own algorithm (too much work and error-prone).
You may use the Free Software tool PROJ as a command line tool
You may want to try to install a rpm of proj:
> I guess that this information is available somewhere as soon as I know what
> projection is used. I want "my" catchment to show up at the right place!
Hope my hints help to get the catchment done soon :-)
Jan-Oliver Wagner http://intevation.de/~jan/
Intevation GmbH http://intevation.de/
More information about the Great-er-list