Geodetic Distances from Latitude and Longitude

Given two sets of points on the earth's surface in latitude, longitude form, returns the geodetic distances in meters between corresponding points.

geoDist(lat1, lon1, lat2, lon2, NAOK = TRUE)

Arguments

lat1, lon1, lat2, lon2

Latitude and longitude co-ordinates for the two sets of points.

NAOK

Are NA values allowed in the co-ordinates? Default: TRUE. If so, corresponding elements of the distance will also be NA.

Value

numeric vector of distances, optionally including NA values if those are allowed and present in any of the coordinates.

Details

Uses a classic Fortran algorithm implementing a method that allows for the non-spherical shape of the earth. See comments in the Fortran code for the history of the implementation.

References

Vincenty,T. (1975). Direct and inverse solutions of geodesics on the ellipsoid with application of nested equations. Survey Review, vol. 23(176):88-94.

Author

John Chambers, Stanford Data Science, Stanford University (formerly at Bell Labs). Transfer of this function from SoDA to adespatial by Guillaume Guénard, with permission of John Chambers.