Correct Answer : Horizontal system
Explanation : Azimuth Elevation system is also known as the Horizontal system because the horizontal plane is taken as reference in it. The equatorial system is another type of coordinate system, which uses the celestial equatorial plane as reference. Ecliptic system is another type of coordinate system, which uses the ecliptic plane as reference. Ecliptic plane is the path traversed by the sun around the earth, keeping earth fixed at the centre of the celestial sphere.
