Geosynchronous and Geostationary Satellites

Geosynchronous Satellite and Geosynchronous Orbit (GSO)

A geosynchronous satellite is a communication satellite that has an orbital period same as the period of rotation of the earth. Hence, it appears to be permanently in the same area of the sky at a particular time each day when viewed by an observer on the earth.

The orbit in which a geosynchronous satellite is placed is called geosynchronous orbit (GSO). Its orbital period is the sidereal day, i.e. 23 hours 56 minutes 4 seconds and its orbital altitude is 35,800 km.

Geostationary Satellite and Geostationary Orbit (GEO)

A circular geosynchronous satellite which is placed at 0^o angle to the equatorial plane is called a geostationary satellite. It appears to be stationary at a fixed position of the sky throughout the day by a ground observer.

The orbit in which a geostationary satellite is placed is called a geostationary orbit (GEO). It is placed 35, 800 km above the earth’s equator and has an orbital period equal to the sidereal day.

Uses and Examples of Geosynchronous Satellites

Uses

• Voice and data communication
• Internet
• Broadcasting cable TV and radio signals

Examples

• Raduga 29 of Russia
• Astra 1C of India
• MEASAT 2 of Malaysia

Uses and Examples of Geostationary Satellites

Uses

• Weather reports about a particular region
• Weather forecasting
• Terrestrial reports of a geographical area
• Spy networks

Examples

• Geostationary Operational Environmental Satellite (GEOS) of USA
• INSAT of India
• Himawari of Japan
• Fengyun of China
• Meteostat of Europe