I have downloaded the Declination Diagram toolbox for ArcGIS 10.2 and am having some difficulties with it's execution.
I follow the instructions provided and have copied the elements into my map.
When running the tool in my projected map (UTM z XX), it does calculate True North and a centroid for my map, however the tool calculates the Magnetic Declination Angle in Decimal Degrees as 'None', and hence it spits out the following:
Magnetic Declination Angle in Decimal Degrees = None
Annual Drift = None
Magnetic Declination Direction = W
Exception : int() argument must be a string or a number, not 'NoneType'
The tool fails to execute.
Can anybody offer any suggestions as to why the tool is calculating the magnetic declination angle as None?