Contents
How to calculate cross track distance to great Cicle line?
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. See this link for code (using GeographicLib) to compute the cross track distance to a geodesic.
How to calculate the cross track path in JavaScript?
This does the ellipsoidal calculation and is accurate to 20 nanometers or so. Also look at “Calculation 2. Distance from a point to a line” on this site. This calculates the cross track path with Javascript and displays the result.
How to calculate the cross track distance to a rhumb line?
The solution for the cross-track distance to a rhumb line is giving in this link which computes an accurate intercept for the WGS84 ellipsoid given a sufficiently accurate initial guess. This computes the shortest geodesic intercept. The geodesic intercept has the nice property that the angle of interception is 90°.
What is the angle of intersection of the loxodrome?
Recall that the loxodrome is the curve on the sphere that intersects each meridian (line of longitude) of the sphere or Earth at the same (spherical) angle. The angle of intersection of loxodrome and meridian I call “alpha”, and I think of alpha as 0 or zero for directly North, alpha = 90 degrees for East.
How to calculate the distance to the rhumb line?
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.
Which is better the Great Circle Line or the rhumb line?
Over a longer oceanic passage, it makes sense to travel on a Great Circle Circle than the Rhumb Line due to the extra time and energy involved. Sailing between Cadiz (Spain) and Miami (US), this could amount to a day’s sailing over the passage ( 150 NM less).
Can a ship follow the great circle route?
To follow the great circle route (also called orthodromic line), a ship must constantly adjust its course. If the ship has a constant course, its route follows a rhumb line (also called loxodromic line), in blue on the simulation.