I was looking over the sectional near KEZF (Shannon). About 5.2 miles at 149°(38.20°N/77.37°W), there is a small black square labeled "geomagnetic center". I've looked in the FAA pubs such as the Aeronautical Chart User's Guide, internet searches, etc. and there is no explanation.
The only reference i can find is the comment "If you’re searching for truth, look in your sectionals for the geomagnetic center!" at "https://www.avweb.com/insider/trsa-asks-can-you-handle-the-truth/"
Anyone know what it is?
The only reference i can find is the comment "If you’re searching for truth, look in your sectionals for the geomagnetic center!" at "https://www.avweb.com/insider/trsa-asks-can-you-handle-the-truth/"
Anyone know what it is?