Geosynchronous vs Geostationary Satellites.
□ Geostationary satellite is a Special case of Geosynchronous satellite.
□ Therefore, it can be said that all Geostationary satellites are Geosynchronous but vice-versa is not true.
□ Geostationary satellite is a geosynchronous satellite whose orbit is circular & is in the plane of Equator.
Hence, a Geostationary satellite appear stationary from any point on Earth. That is why it is used in communication & broadcasting extensively as you can point a TV satellite antenna to a particular direction which can be fixed & will always point to the Goestationary satellite.
While the Geosynchronous satellites have elliptical & inclined orbits.
If elliptical is made circular (a=b),
angle of inclination with Equator is made = zero,
then the satellite is called as Geostationary satellite.
Since, the geosynchronous satellites are not stationary wrt the Earth therefore Tracking Antennas are used. From the ground, the geosynchronous satellites oscillate daily from a fixed point.
P.S.1. The time period of both Geosynchronous as well as Geostationary is Earth’s sidereal rotation period that is approximately 24 hours.
P.S.2. Geosynchronous satellite orbits can be many but Geostationary satellite orbit is only one.
With Great Love,
Er. Amit Yadav