Rotation Matrix from J2000 Equatorial to Horizontal — astro_rotation_EQJ

Calculates a rotation matrix from J2000 mean equator (EQJ) to horizontal (HOR).

Usage

astro_rotation_EQJ_HOR(time, latitude, longitude, height)

Arguments

time: A POSIXct object representing the date and time of observation.
latitude: The observer's geographic latitude in degrees.
longitude: The observer's geographic longitude in degrees.
height: The observer's elevation above sea level in meters.

Value

A rotation matrix that converts EQJ to HOR. The components represent: x = north, y = west, z = zenith (straight up from observer).

Details

This is one of the family of functions that returns a rotation matrix for converting from one orientation to another.

Source: EQJ = equatorial system, using the equator at J2000 epoch.

Target: HOR = horizontal system (x=North, y=West, z=Zenith).

Examples

astro_rotation_EQJ_HOR(Sys.time(), latitude = -35.28, longitude = 149.12, height = 0)
#>            [,1]        [,2]       [,3]
#> [1,] -0.2962078  0.85630807 -0.4230809
#> [2,]  0.4946108  0.51646067  0.6990197
#> [3,]  0.8170809 -0.00220526 -0.5765189