Plane Azimuth- magnetic, true or grid values?..?

[havardnesgmail.com]

Hi!

What kind of azimuth values should I use when defining the plane azimuth? Magnetic, true or grid values?

Thanks!

[André Mermoud]

In PVsyst, the azimuth is defined as function of the geometric "true" North (or South) , i.e. parallel to a longitude line.

[havardnesgmail.com]

Thanks! Maybe it was a dumb question, since i couldn't find it in the FAQ nor the web.

Håvard

[Soldnerkugel]

Hi!

What kind of azimuth values should I use when defining the plane azimuth? Magnetic, true or grid values?

Thanks!

Magnetic declination is not constant, it is varying. magnetic meridians are not parallel, therefore it is not useful to use magnetic north/ south as a reference. You need a reference which is constant, so you only can use geographic north/ south (although this reuqires an approximation of the shape of planet earth as it is not able to be modelled by mathematic functions. Grid north/ south is also not applicable as grid north/ south depends on the mapping projection. I.e. there are mapping projections which are non-cartesian: Lambert projection in France, Krovak projection in Czech republic etc etc. always bear in mind that there is a difference between grid north and true north. I.e. in check republic this difference can reach up to ca. 12 degrees. Even cartesian projections like Gauß-Krüger, OS Grid, UTM differ from true north.