Rotation Angle to magnetic north

[StanleyHo]

Hi,

I was wondering if it is possible to get the rotation angle of the polygon  to magnetic (true) north.

thanks

[DominiqueBroux · Accepted solution]

Magnetic North is dépendent on your location and on the date.

The NGDC provides a service returning this value: http://www.ngdc.noaa.gov/geomag-web/calculators/declinationHelp

For example in PDF or in XML.

[StanleyHo]

thanks for the reply.

I will look into it