distance: Great circle distance between geographical coordinates

In argosfilter: Argos Locations Filter

Great circle distance between geographical coordinates

Description

Function distance calculates the distance, in km, between two geographical locations following the great circle route. Function distanceTrack calculates the distance, in km, between a sequence of locations.

Usage

distance(lat1, lat2, lon1, lon2)
distanceTrack(lat,lon)

Arguments

lat1	latitude of the first location, in decimal degrees
lat2	latitude of the second location, in decimal degrees
lon1	longitude of the first location, in decimal degrees
lon2	longitude of the second location, in decimal degrees
lat	vector of latitudes, in decimal degrees
lon	vector of longitudes, in decimal degrees

Details

Distances are calculated using spherical trigonometry. See details on formulae in Zwillinger (2003).

Value

distance returns the distance between the two locations. distanceTrack returns a vector of distances between the sequence of locations. In both cases, distances are given in km.

Author(s)

Carla Freitas

References

Zwillinger D. (2003) Standard Mathematical Tables and Formulae, 31st edition. Chapman & Hall/CRC, Boca Raton, FL.

See Also

bearing

Examples

# Distance between two geographical locations
lat1<-rnorm(1,80)
lon1<-rnorm(1,20)
lat2<-rnorm(1,80)
lon2<-rnorm(1,20)
distance(lat1,lat2,lon1,lon2)

# Distance between a sequence of 10 geographical locations:
lat<-rnorm(10,80)
lon<-rnorm(10,20)
distanceTrack(lat,lon)

argosfilter documentation built on Sept. 13, 2022, 5:05 p.m.