OPERATION:
1. Enter your Latitude and Longitude in "Lat 1" and "Long 1". Enter Lat/Long in the form DD.dddddd (do not use a negative sign for West longitudes or South latitudes) or DD:MM.mmm or DD:MM:SS.ss, where colons separate degrees, minutes and seconds. Different styles may be used for each Lat/Long entry. Entry of decimal places is not required for the calculator to operate, but all four lat/long boxes must have something entered (even a single zero).
2. Select desired distance units and earth model, and click on the "COMPUTE" box.
3. If the calculation does not complete click the "RESET KBS LAT/LONG" button, re-enter your lat/long, then click "COMPUTE" again.
4. For calculating coordinates for kBS click the "RESET kBS LAT/LONG" button, re-enter your lat/long, then click "COMPUTE".
Notes
1. Conversion factors used (exact figures, by international definition): International Nautical Mile = 1852m; Statute Mile = 5280ft; 2.54cm = 1 inch = 1/12 ft.
2. Above about 89 degrees latitude, and between near-antipodal (opposite) points, courses may not be accurate.
Calculation program: by Ed Williams. Calculations use the Vicenty Algorithm (Source: Direct and Inverse Solutions of Geodesics on the Ellipsoid with Application of Nested Equations, Survey Review, XXII, 176 (1975)). See also the Aviation Formulary (http://www.best.com/~williams/avform.htm), also by Ed Williams.
Text: by Ian Strachan (highly edited by Leo)