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Cavewhere / cavewhere

3D Cave Mapping Software
https://cavewhere.com
GNU General Public License v3.0
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Compass Declination +/- #140

Open erichahn opened 6 years ago

erichahn commented 6 years ago

Note on declination in cavewhere is helpful. If https://www.ngdc.noaa.gov/geomag-web/ tells me I have an 8 degree west declination does that mean I enter + 8 or -8 into cavewhere?

Conversion Site

Magnetic + Declination = True Bearing.

THIS ONE? 100 magnetic + +8W declination = 108?

100 Magnetic + -8W Delcination = 92?

NOAA says: Declination: The angle of difference between true North and magnetic North. For instance, if the declination at a certain point were 10° W, then a compass at that location pointing north (magnetic) would actually align 10° W of true North. True North would be 10° E relative to the magnetic North direction given by the compass. Declination varies with location and slowly changes in time.

vpicaver commented 4 years ago

You should enter -8. I need to make cave where update automatically.