Function Rotation_HOR_EQJ

Rotation_HOR_EQJ(time: FlexibleDateTime, observer: Observer): RotationMatrix
Calculates a rotation matrix from horizontal (HOR) to J2000 equatorial (EQJ).

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 the J2000 epoch.
Parameters
- time: FlexibleDateTime
  The date and time of the observation.
- observer: Observer
  A location near the Earth's mean sea level that defines the observer's horizon.
Returns RotationMatrix
A rotation matrix that converts HOR to EQJ at time and for observer.