// Distance from London to Paris
echo GreatCircle::distance(51.507222, -0.1275, 48.8567, 2.3508);
// Output: 343.46748684413

// Distance from JFK airport to La Guardia airport in feet
echo GreatCircle::distance(40.63980103, -73.77890015, 40.77719879, -73.87259674, "FT");
// Output: 56425.612628758

// Distance between North and South poles on Mars (3389.5 is mean radius of Mars in kilometers)
echo GreatCircle::distance(90, 0, -90, 0, 3389.5);
// Output: 10648.428299343

// Distance between Moscow and New York in furlongs (31670.092 is Earth radius in furlongs)
echo GreatCircle::distance(55.75, 37.616667, 40.7127, -74.0059, 31670.092);
// Output: 37335.295755141

// Bearing from Paris to London in decimal degrees
echo GreatCircle::bearing(48.8567, 2.3508, 51.507222, -0.1275);
// Output: 330.03509575101

// Coordinates of a location 100 KM away from Paris, traveling in the direction of London
$dest = GreatCircle::destination(48.8567, 2.3508, 330.035, 100);
printf("Latitude: %f, Longitude: %f", $dest["LAT"], $dest["LON"]);
// Output: Latitude: 49.633753, Longitude: 1.657274

// Coordinates of a location 500 nautical miles away from Paris, traveling in the direction of New York
$brg = GreatCircle::bearing(48.8567, 2.3508, 40.7127, -74.0059);
$dest = GreatCircle::destination(48.8567, 2.3508, $brg, 500, "NM");
printf("Latitude: %f, Longitude: %f", $dest["LAT"], $dest["LON"]);
// Output: Latitude: 51.306719, Longitude: -10.071875