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2D-Cartesian Grid for Europe

Posted: Wed Jan 07, 2009 2:46 pm
by GreekBoy
Hello,

Thanks for the excellent GpsTools product. I mostly use it for conversions between different datum/grid systems. I am already a registered user.

I am new in the area and I have an urgent question:

I just started developing a fleet management software that, until now, has been intended for Greece and the GGRS87 Grid worked perfectly.

From now on, the software should be able to work on a paneuropean basis. Obviously, the GGRS87 Grid is no more accurate (shifts eastings or northings while in other countries).

Thus, I need a new Grid system that covers the whole Europe. Due to the nature of the calculations in the software, it should remain two dimensional (UTM_NORTH that additionally uses the zone would pose severe changes in the business logic). Moreover, I need to be able to calculate distances using pythagorean theorem for distances in different countries like I did using the Greek Grid System until now.

What kind of solution would you recommend for my problem?

Any answer is welcome and highly appreciated, thanks in advance!

RE: 2D-Cartesian Grid for Europe

Posted: Wed Jan 07, 2009 2:54 pm
by johan
For larger areas like whole Europe you cannot use a grid, and you cannot use Pythagorean theorem to calculate distances. This is because The Earth is a sphere and grids makes different kind of approximations to make it "flat".

You need to use a datum longitude/latitude. The best choice is WGS84. To calculate distances over a datum you use Great Circle Distance calculations. More info here:
http://franson.com/gpstools/reference_manual.asp?comp=tools&class=Position&item=Distance&platform=net

Regards,
Johan

Franson Support

RE: 2D-Cartesian Grid for Europe

Posted: Fri Oct 23, 2009 2:23 am
by thomasv
Hello GreekBoy,

i am trying to develop a pda application using GGRS87 maps.
i have worked previously with WGS84 with no problem.

Can you please advise me what i have to do to work with GGRS87. i create the maplib and i load it in the application but i cannot see it.

Your help will be very much appreciated.

Many thanks

Thomas