How to calculate cross track distance to great cicle line and rhumb line?
For great circle line, I've tried this formula, but it is not accurate while the distance is less than 0.1nm.
For rhumb line, I've applied the cartesian vector projection method(see: dist_Point_to_Segment). Take one point as origin and calculate vectors based on rhumb distance and bearing. Then find the closest point on rhumb line, and calculte great circle distance on it. But I'm not sure whether this method is correct for the case.