Magnetic North is certainly a difficult thing to take into account these days ..
Currently accelerating and shifting between 35 and 40 miles a year toward Russia..
This equates to roughly 1 degree per year..
The rate of accelerated shift is apparently moving faster atm than at any time in human history ...or so its said.
So this deviation from the true north to magnetic compass points has to be taken into consideration when calculating to install satellite dishes with the aid of a compass.
Not to mention the effects on aviation etc..
Also probably responsible in part for the Climate changes which we humans are compounding.
I believe the current deviation is around 10 > 11 degrees East of true north