Rotation Matrix from ECL to HOR — astro_rotation_ECL

Calculates a rotation matrix from J2000 mean ecliptic (ECL) to horizontal (HOR).

Usage

astro_rotation_ECL_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 ECL to HOR. The components of the horizontal vector are: x = north, y = west, z = zenith (straight up from the observer).

Details

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

Source: ECL = ecliptic system, using equator at J2000 epoch.

Target: HOR = horizontal system (x = north, y = west, z = zenith).

Examples

astro_rotation_ECL_HOR(Sys.time(), latitude = -35.28, longitude = 149.12, height = 0)
#>           [,1]       [,2]       [,3]
#> [1,] 0.4408241  0.6503593  0.6186331
#> [2,] 0.6689301 -0.6975928  0.2567038
#> [3,] 0.5985037  0.3006611 -0.7425606