Returns the ground distance, in nautical miles, from the user's aircraft to the specified latitude and longitude.
Note: As distances increase, this function becomes less accurate.
Syntax
Ground_Distance (lat, lon)
where
| lat | Specifies the latitude. | 
| lon | Specifies the longitude. | 
Example
DECLARE GD2_Meigs
GD2_Meigs = GROUND_DISTANCE(41:51:13.3942, 087:36:27.2470)