eci2geo: Convert Earth-centered inertial coordinates to geographic...

In astrolibR: Astronomy Users Library

Description

Convert Earth-centered inertial coordinates to geographic spherical coordinates

Usage

eci2geo(eci_xyz, jdtim)

Arguments

eci_xyz	ECI [X,Y,Z] coordinates (in km), can be an array [3,n] of n such coordinates.
jdtim	Julian Day time, double precision. Can be a 1-D array of n such times.

Details

Converts from ECI (Earth-Centered Inertial) (X,Y,Z) rectangular coordinates to geographic spherical coordinates (latitude, longitude, altitude). JD time is also needed as input.

ECI coordinates are in km from Earth center. Geographic coordinates are in degrees/degrees/km. Geographic coordinates assume the Earth is a perfect sphere, with radius equal to its equatorial radius.

gcoord can be further transformed into geodetic coordinates (using astrolib geo2geodetic) or into geomagnetic coordinates (using geo2mag)

Value

lat, lon, alt

3-element array of geographic [latitude,longitude,altitude], or an array [3,n] of n such coordinates, double precision

Author(s)

Written by Pascal Saint-Hilaire ([e-mail]) on 2001/05/13

R adaptation by Arnab Chakraborty (June 2013)

See Also

ct2lst

Examples

eci2geo(c(6378.137+600, 0, 0), 2452343.38982663)  # result 0.0000000  232.27096 600.00000

Example output

[1]   0.000 232.271 600.000

astrolibR documentation built on May 2, 2019, 3:26 a.m.