spheroid.distance: Vincenty Direct Calculation of Distance and Direction

In jeffreyevans/landmetrics: Legacy landscape metrics from spatialEco

Vincenty Direct Calculation of Distance and Direction

Description

Estimates the distance on a sphere using lat and long coordinates

Usage

spheroid.distance(lat1, lon1 = NULL, lat2 = NULL, lon2 = NULL, bearing = FALSE)

Arguments

lat1	a single value or vector of values representing latitude in decimal degrees from -90 to 90 degrees. Alternatively, a data.frame or matrix can be used here with each column representing lat1, lon1, lat2, lon2 (in that order).
lon1	a single value or vector of values representing longitude in decimal degrees from -180 to 180 degrees. If NULL, lat1 is assumed to be a matrix or data.frame.
lat2	a single value or vector of values representing latitude in decimal degrees from -90 to 90 degrees. If NULL, lat1 is assumed to be a matrix or data.frame.
lon2	a single value or vector of values representing longitude in decimal degrees from -180 to 180 degrees. If NULL, lat1 is assumed to be a matrix or data.frame.
bearing	boolean value as to calculate the direction as well as the distance.

Value

Returns a data.frame with:

• lon1 - the original longitude

• lat1 - the original latitude

• lon2 - the destination longitude

• lat2 - the destination latitude

• distance - the distance used

• bearing - if requested, the bearing between the two points

Note

The spheroid.distance estimates the distance given a starting and ending latitude and longitude. Vincenty's approach, is described as: Vincenty's formula are two related iterative methods used in geodesy to calculate the distance between two points on the surface of an spheroid. They are based on the assumption that the figure of the Earth is an oblate spheroid, and hence are more accurate than methods such as great-circle distance which assume a spherical Earth. Note: this method assumes a locations are lat & lon given in WGS 84.Direction, if requested, is the the initial bearing (sometimes referred to as forward azimuth) which one would follow as a straight line along a great-circle arc from start to finish. That this will fail if there are NA's in the data.

Author(s)

Jeremy VanDerWal (depreciated/orphaned SDMTools package) and Jeffrey S. Evans

References

Vincenty, T. (1975). Direct and Inverse Solutions of Geodesics on the Ellipsoid with application of Nested Equations. Survey Review, vol XXII no 176.

jeffreyevans/landmetrics documentation built on Nov. 14, 2023, 3:13 p.m.