# Rotating observer plane inside celestial sphere with a given coordinates, time and date [duplicate]

I have plotted stars around the surface of a celestial sphere. At the centre of this sphere, I have a brown plane which is the land. This plane can be rotated in the x,y and z axis.

When x,y,z rotation of the plane is set to 0,0,0:

Front View:

Top View:

Bottom View:

After the user inputs the latitude, longitude, time and date, the plane should position itself correctly so that the correct stars are above the plane.

How do I accomplish this and what is the mathematics what links latitude, longitude and the rotation of Earth depending on the time and date to the rotation of the plane in 3-dimensions?

• From my understanding, I need to calculate the altitude and azimuth of each star using the local sidereal time of the observer to position the stars correctly. This means that the plane is fixed but the stars move. Is my understanding correct?
– SidS
Commented Jun 6, 2020 at 18:52
• Any way to get the ground's normal vector pointing in the same direction as the (RA, Dec) of the zenith is fine. The ground can be what moves. Alt-az coordinates are optional. Commented Jun 6, 2020 at 19:39