Enter lat/lon of points, select distance units and earth model and click
"compute". Lat/lons may be entered in DD.DD, DD:MM.MM or
DD:MM:SS.SS formats.

Note that if either point is very close to a pole,
the course may be inaccurate, because of its extreme sensitivity to position
and inevitable rounding error.

Enter lat/lon of initial point, true course and distance.
Select distance units and earth model and click
"compute". Lat/lons may be entered in DD.DD, DD:MM.MM or
DD:MM:SS.SS formats.

Note that the starting point cannot be a pole.

Distance Units:
Earth model:

Spheroid

Enter "user defined" spheroid parameters here:

History

6/8/03 Added option to get distance in feet

11/4/02 Added references.

8/20/01 Added FAI sphere. Made statute mile conversion to 10 sig figs
instead of 6.

3/23/00 Added warning notes about not starting at poles.
Changed default ellipsoid to WGS84

7/13/98 Removed a line of debugging code, giving irritating Javascript alerts, left
over from the 5/16/98 changes

5/16/98
Changed the great circle radial and distance algorithm to one valid for
unlimited distances. Previous was only valid for ranges up to one quarter of
the earth's circumference in longitude.
Note that the Vicenty algorithm for (ellipsoidal) course and distance may
fail to converge correctly, or at all, if the final point is within 37'
of arc of the antipodes of the first point.

5/12/98 Eccentricity of NAD27 (Clarke1866) ellipsoid obtained from my reference
"Coordinate Systems and Map Projections" by D. H. Maling was in error.
1/f changed from 298.97866982 to 294.9786982138

11/9/97 Fixed bug where if the output lat/lon was DD 6.MMMM (ie 6 minutes),
the result was incorrectly rounded up to the next degree.

3/4/97 Fixed bug where deg/minute entries 08 or 09 would be (mis)read in octal!