Rotation Matrix from Horizontal to J2000 Equatorial — astro_rotation_HOR

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

Usage

astro_rotation_HOR_EQJ(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 HOR to EQJ at time and for the observer.

Details

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

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

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

Examples

astro_rotation_HOR_EQJ(Sys.time(), latitude = -35.28, longitude = 149.12, height = 0)
#>            [,1]      [,2]         [,3]
#> [1,] -0.2962250 0.4946004  0.817080916
#> [2,]  0.8562901 0.5164905 -0.002205216
#> [3,] -0.4231052 0.6990051 -0.576518788