RE: Distance between 2 WGS84-LatLon Coordinates

Hi -

I'm not sure if the WGS84 distinguishes the coordinates from regular
coordinates, but here is a method which computes (estimates really) the
distance between two lat/lon coordinates:

  // 6367 is "standard" radius of earth in km
  // 1.852 is km per Nautical Mile; this converts R to radius in naut miles
  private final static double R = 6367.0 / 1.852;
  private final static double RADIANSPERDEGREE = 0.017453293;

  private double computeDistance(double lat1, double lon1, double lat2,
double lon2)
  {
    // all values are of type "double"; lat1,lon1,lat2 and lon2 are the
    // coordinates we are using in the calculation, in RADIANS.
    // You will have to convert from degrees to radians using the
    // conversion factor, RADIANSPERDEGREE
    lat2 = lat2 * RADIANSPERDEGREE;
    lon2 = lon2 * RADIANSPERDEGREE;

    double dlon = lon2 - lon1; // difference in longitude
    double dlat = lat2 - lat1; // difference in latitude

    double a = (Math.sin(dlat/2.0)* Math.sin(dlat/2.0)) +
                 (Math.cos(lat1) * Math.cos(lat2) *
                  Math.sin(dlon/2.0) * Math.sin(dlon/2.0));

    double c = 2.0 * Math.asin(Math.sqrt(a));

    return (R * c); // Final distance is in nautical miles.
  }

Hope that helps. I couldn't find any means of calculating distances between
two lat/lon points in OpenMap so I borrowed one from the net. This gives the
result in nautical miles.

  - Chris

> -----Original Message-----
> From: owner-openmap-users@bbn.com [mailto:owner-openmap-users@bbn.com]On
> Behalf Of Gubler, Rüdiger
> Sent: Thursday, March 07, 2002 8:57 AM
> To: Openmap-Users (E-Mail)
> Subject: Distance between 2 WGS84-LatLon Coordinates
>
>
>
> Hello,
>
> in which way can i calculate the distance
> between two WGS84-LatLon Coordinates?
>
>
> Thanks Rüdiger
>
> --
> [To unsubscribe to this list send an email to "majdart@bbn.com"
> with the following text in the BODY of the message "unsubscribe
> openmap-users"]

--
[To unsubscribe to this list send an email to "majdart@bbn.com"
with the following text in the BODY of the message "unsubscribe openmap-users"]