الأقمار الصناعية والمدارات المغلقة

• Satellites utilize various closed orbits for operation.

Geosynchronous Orbit

• Geosynchronous orbit is a high Earth orbit.
• Satellites in geosynchronous orbit have an orbital period matching the Earth's rotation period.
• The altitude of a geosynchronous orbit is approximately 35,786 km (22,236 miles) above the Earth's equator.
• A special case of geosynchronous orbit is the geostationary orbit.
• Satellites in geostationary orbit appear stationary relative to a point on the Earth's surface.
• Geostationary orbits are achieved by maintaining a zero inclination with respect to the Equator.
• Geosynchronous orbits are valuable for communication satellites.
• These satellites provide continuous coverage to specific areas on Earth.
• Weather forecasting is another application of satellites in geosynchronous orbit.
• It allows for continuous monitoring of weather patterns.

Sun-synchronous Orbit

• Sun-synchronous orbit is a near-polar orbit.
• Satellites in sun-synchronous orbit pass over a particular location at the same local solar time.
• The orbit is designed to precess (rotate) around the Earth.
• The precession matches the Earth's yearly orbit around the Sun.
• The typical altitude of a sun-synchronous orbit is between 600 to 800 km.
• Satellites in sun-synchronous orbit are useful for Earth observation.
• This includes imaging and remote sensing.
• Consistent lighting conditions are ensured as the satellite passes over different locations.
• This is due to the fixed angle between the satellite, the Sun, and the Earth.
• This consistent lightning improves the quality and comparability of images taken over long periods.