Geo-Stationary and Sun
Synchronous Satellites
Presented by: Tilok Chetri
MSc GIS and RS
Introduction
The path followed by a satellite is referred to as its orbit.
An object in orbit is called a satellite.
A satellite can be natural, like the moon or it can be
human-made like, like the space station.
The moon goes in orbit around Earth.
Satellite orbits are matched to the capability and
objective of the sensor(s) they carry.
Orbit selection can vary in terms of altitude and their
orientation and rotation relative to the Earth.
Various orbits are possible depending on the inclination of the
orbital plane with the plane containing the earth’s equator.
Orbits
Schematics showing different types of orbits
Apogee: It is a point on the orbit where
distance of the satellite from the
Earth’s surface is maximum.
Perigee: It is a point on the orbit where
distance of the satellite from the
Earth’s surface is smallest.
Inclination: The angle between the
plane of orbit of the satellite and plane
of the equator of Earth is called
inclination of the orbit.
The following three parameters define the orbit of a satellite
Polar
Sun Synchronous
Geo Synchronous
Types of Orbits
Types of Orbits
Near Polar Orbits
These orbits have an inclination near 90
degrees.
This allows the satellite to see virtually
every part of the Earth.
It takes approximately 90 minutes for
the satellite to complete one orbit.
These satellites have many uses such as
measuring ozone concentrations in the
stratosphere or measuring temperatures
in the atmosphere.
Sun Synchronous Orbits
These orbits allows a satellite to pass
over a section of the Earth at the same
time of day.
These satellites orbit at an altitude
between 700 to 800 km.
These orbits are used for satellites that
need a constant amount of sunlight.
Satellites that take pictures of the
Earth would work best with bright
sunlight.
Types of Orbits
Diagram showing orbit of sun-synchronous satellite
Geo Synchronous Orbits
It is also known as geostationary orbits,
satellites in these orbits circle the
Earth at the same rate as the Earth
spins.
These satellites are used to study large
scale phenomenon such as hurricanes,
or cyclones.
These orbits are also used for
communication satellites.
The other disadvantage is that these
satellites have trouble monitoring
activities near the poles.
Types of Orbits
A satellite is an object put into orbit around the earth or any
other planet in order to relay communication signals or transmit
scientific data.
Satellites
Geo Synchronous Satellite
It is parked in space 35,790
km above the equator of the
stationary earth.
At this altitude, one orbit
takes approx. 24 hours to
rotate.
Uses:
weather forecasting
satellite television
satellite radio etc.
Geostationary satellite
Sun Synchronous Satellite
Those satellites that moves
around the earth and
always gets its power source
from the sun.
Located approx. 750 km
above the surface of the
earth
Landsat, Quick bird etc.
Uses:
Military purposes
Remote Sensing
Thank you. . .
Types of Orbits• Different orbits serve different purposes. Each has its own advantages and disadvantages. There are
several types of orbits:
• Polar
• Sun Synchronous
• Geosynchronous
• Near Polar Orbits
• These orbits have an inclination near 90 degrees..
• This allows the satellite to see virtually every part of the Earth as the Earth rotates underneath it.
• It takes approximately 90 minutes for the satellite to complete one orbit.
• These satellites have many uses such as measuring ozone concentrations in the stratosphere or measuring temperatures in the atmosphere.
• Sun Synchronous Orbits
• These orbits allows a satellite to pass over a section of the Earth at the same time of day.
• These satellites orbit at an altitude between 700 to 800 km.
• These orbits are used for satellites that need a constant amount of sunlight.
• Satellites that take pictures of the Earth would work best with bright sunlight, while satellites that measure long wave radiation would work best in complete darkness
• Geo Synchronous Orbits
• Also known as geostationary orbits, satellites in these orbits circle the Earth at the same rate as the Earth spins.
• The satellites are located near the equator so there is a constant force of gravity all directions. Geosynchronous orbits allow the satellite to observe almost a full hemisphere of the Earth.
• These satellites are used to study large scale phenomenon such as hurricanes, or cyclones.
• These orbits are also used for communication satellites.
• The disadvantage of this type of orbit is that since these satellites are very far away, they have poor resolution. The other disadvantage is that these satellites have trouble monitoring activities near the poles.
Introduction• Moon revolves around the Earth, It is a natural satellite
• A satellite launched by man around any planet for our own purpose is called an artificial satellite or man-made satellite. Sputnik-I, Explorer-I, GSAT-I and GSAT-II are examples of artificial satellites.
• Satellites provide a great deal of the remote sensing imagery commonly used today
• The path followed by a satellite is referred to as its orbit. Satellite orbits are matched to the capability and objective of the sensor(s) they carry. Orbit selection can vary in terms of altitude (their height above the Earth's surface) and their orientation and rotation relative to the Earth.
