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Station Declination & Zero Bearing Direction
The The VOR.zeroBearingDirection is is used to code the direction of the 'zero bearing' provided by the station. For example: magnetic north ('MAG'), true north ('TRUE').
The angular difference between the direction of the 'zero bearing' indicated by the station and the direction of the True North at the time the VOR station is calibrated is coded by the attribute VOR.declination.
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