Vincenty geodesic distance in WWJ

[nlneilson]

WWJ has a clipped version of the Vincenty Formula in:
worldwind/geom/LatLon.java #627

    public static double ellipsoidalDistance(LatLon p1, LatLon p2, double equatorialRadius, double polarRadius)

Here is how it can be implemented.

//=======================  Vincenty
		    LatLon p1;
		    LatLon p2;
		    double eqR = 6378137.0;     // equatorialRadius  for Earth WGS84
		    double poR = 6356752.3142;  // polarRadius
		    
//		    p1 = LatLon.fromDegrees(loc[0], loc[1]);
//		    p2 = LatLon.fromDegrees(34.2124, -119.1935);

		    p1 = LatLon.fromDegrees(33.94, -118.40); // LAX
		    p2 = LatLon.fromDegrees(41.98, -87.90);  // O'Hare, Chicago

		    double geoDist = LatLon.ellipsoidalDistance(p1, p2, eqR, poR);
		    System.out.println(String.format("%.6fm geodesic distance", geoDist));

2807507.159913m geodesic distance

OK to 4 decimal places in WWJ (.1mm LAX to O'Hare in Chicago)

Just to compare it with the full Vincenty Formula:

Vincenty Inverse Input
Lat1 33.940000 Lon1 -118.400000
Lat2 41.980000 Lon2 -87.900000
Output
s = 2807507.159896060000
aIn = 62.464405076619 aFn = 81.551461342173

Vincenty Direct Input
Lat1 33.940000 Lon1 -118.400000
s = 2807507.159896060000 aIn = 62.464405076619
Output
Lat2 41.979999999984 Lon2 -87.900000000145
aFn = 81.551461342076

OK to 9 decimal paces