# Inclination (i)

Inclination is the angle between the Earth’s equatorial plane and the plane of the orbit. It describes the “tilt” of the orbit. A higher inclination will cover higher latitude values.

To the right is a ground track. It is the projection of the satellite’s orbit onto Earth's surface. Ground tracks vary based on the satellite’s orbital elements which define its motion.

The inclination can be determined by observing the satellite’s ground track. The latitude of the point furthest from the equator determines the satellite’s inclination.

Prograde (0° ≤ i < 90°)

• Orbit velocity is in the same direction as Earth’s rotation.

Retrograde (90° < i ≤ 180°)

• Orbit velocity is in the opposite direction as Earth’s rotation.

Special Case (i = 90°)

• Known as a polar orbit which covers all latitudes. This is useful for global observing satellites.