Types of satellites

<2/”>a >Satellites based on application can be categorized as follows:

Earth Observation satellite->

Starting with IRS-1A in 1988, ISRO has launched many operational remote sensing satellites. Today, India has one of the largest constellations of remote sensing satellites in operation. Currently, *thirteen* operational satellites are in Sun-synchronous orbit – RESOURCESAT-1, 2, 2A CARTOSAT-1, 2, 2A, 2B, RISAT-1 and 2, OCEANSAT-2, Megha-Tropiques, SARAL and SCATSAT-1, and *four* in Geostationary orbit- INSAT-3D, Kalpana & INSAT 3A, INSAT -3DR. Varieties of instruments have been flown onboard these satellites to provide necessary data in a diversified spatial, spectral and temporal resolutions to cater to different user requirements in the country and for global usage. The data from these satellites are used for several applications covering agriculture, water Resources, urban planning, rural development, mineral prospecting, Environment, Forestry, ocean resources and Disaster Management.

Communication satellite->

The Indian National Satellite (INSAT) system is one of the largest domestic communication satellite systems in Asia-Pacific region with nine operational communication satellites placed in Geo-stationary orbit. Established in 1983 with commissioning of INSAT-1B, it initiated a major revolution in India’s communications sector and sustained the same later. GSAT-18 joins the constellation of INSAT System consisting 14 operational satellites, namely – INSAT-3A, 3C, 4A, 4B, 4CR, 3DR and GSAT-6, 7, 8, 10, 12, 14, 15 and 16.

The INSAT system with more than 200 transponders in the C, Extended C and Ku-bands provides Services to telecommunications, television broadcasting, satellite newsgathering, societal applications, weather forecasting, disaster warning and Search and Rescue operations.

 

Navigation satellite->

Satellite Navigation service is an emerging satellite based system with commercial and strategic applications. ISRO is committed to provide the satellite based Navigation services to meet the emerging demands of the Civil Aviation requirements and to meet the user requirements of the positioning, navigation and timing based on the independent satellite navigation system. To meet the Civil Aviation requirements, ISRO is working jointly with Airport Authority of India (AAI) in establishing the GPS Aided Geo Augmented Navigation (GAGAN) system. To meet the user requirements of the positioning, navigation and timing services based on the indigenous system, ISRO is establishing a regional satellite navigation system called Indian Regional Navigation Satellite System (IRNSS).

(a) GPS Aided GEO Augmented Navigation (GAGAN):

This is a Satellite Based Augmentation System (SBAS) implemented jointly with Airport Authority of India (AAI). The main objectives of GAGAN are to provide Satellite-based Navigation services with accuracy and Integrity required for civil aviation applications and to provide better Air Traffic Management over Indian Airspace. The system will be interoperable with other international SBAS systems and provide seamless navigation across regional boundaries. The GAGAN Signal-In-Space (SIS) is available through GSAT-8 and GSAT-10.

(b) Indian Regional Navigation Satellite System (IRNSS) : NavIC

This is an independent Indian Satellite based positioning system for critical National applications. The main objective is to provide Reliable Position, Navigation and Timing services over India and its neighbourhood, to provide fairly good accuracy to the user. The IRNSS will provide basically two types of services

Standard Positioning Service (SPS)

Restricted Service (RS)

Space Segment consists of seven satellites, three satellites in GEO stationary orbit (GEO) and four satellites in Geo Synchronous Orbit (GSO) orbit with inclination of 29° to the equatorial plane. This constellation of seven satellites was named as “NavIC” (Navigation Indian Constellation) by the Honourable Prime Minister of India, Mr. Narendra Modi and dedicated to the Nation on the occasion of successful launch of IRNSS-1G, the seventh and last satellite of NavIC. All the satellites will be visible at all times in the Indian region. All the seven Satellites of NavIC, namely, IRNSS-1A, 1B, 1C, ID,1E, 1F and 1G were successfully launched on July 02, 2013, Apr 04, 2014, Oct 16, 2014, Mar 28, 2015, Jan 20, 2016, Mar 10, 2016 and Apr 28, 2016 respectively and all are functioning satisfactorily from their designated orbital positions.

Ground Segment is responsible for the maintenance and operation of the IRNSS constellation. It provides the monitoring of the constellation status, computation of the orbital and clock parameters and navigation data uploading. The Ground segment comprises of TTC & Uplinking Stations, Spacecraft Control Centre, IRNSS Timing Centre, CDMA Ranging Stations, Navigation Control Centre and Data Communication Links. Space segment is compatible with single frequency receiver for Standard Positioning Service (SPS), dual frequency receiver for both SPS & RS service and a multi mode receiver compatible with other GNSS providers.

 

Experimental satellite->

ISRO has launched many small satellites mainly for the experimental purposes. This experiment include Remote Sensing, Atmospheric Studies, Payload Development, Orbit Controls, recovery technology etc. Example- INS-1A, INS-1B, YOUTHSAT, APPLE

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Satellites are artificial objects that are placed in orbit around the Earth or another celestial body. They are used for a variety of purposes, including communication, navigation, meteorology, and astronomy.

Communication satellites are used to transmit voice, data, and video signals between different points on Earth. They are typically placed in geostationary orbit, which is an orbit that is 35,786 kilometers above the Earth’s equator. This orbit allows the satellite to remain in a fixed position relative to the Earth’s surface, which makes it ideal for communication purposes.

Earth observation satellites are used to monitor the Earth’s surface and Atmosphere. They can be used to track weather patterns, monitor deforestation, and map changes in land use. Earth observation satellites are typically placed in low Earth orbit, which is an orbit that is 160 to 2,000 kilometers above the Earth’s surface. This orbit allows the satellite to take high-resolution images of the Earth’s surface.

Navigation satellites are used to provide precise location and time information to users on Earth. They are typically placed in medium Earth orbit, which is an orbit that is 2,000 to 20,000 kilometers above the Earth’s surface. This orbit allows the satellite to provide continuous coverage of the Earth’s surface.

Meteorological satellites are used to monitor the Earth’s atmosphere and weather patterns. They can be used to predict the weather, track hurricanes, and monitor Air Pollution. Meteorological satellites are typically placed in geostationary orbit, which is an orbit that is 35,786 kilometers above the Earth’s equator. This orbit allows the satellite to remain in a fixed position relative to the Earth’s surface, which makes it ideal for weather forecasting.

Scientific satellites are used to conduct scientific experiments in space. They can be used to study the Sun, the planets, and other celestial bodies. Scientific satellites are typically placed in low Earth orbit, which is an orbit that is 160 to 2,000 kilometers above the Earth’s surface. This orbit allows the satellite to take high-resolution images of the Earth’s surface and to conduct experiments in the near-Earth environment.

Military satellites are used for a variety of purposes, including reconnaissance, surveillance, and communications. They can be used to track enemy movements, monitor troop deployments, and provide communications links between ground forces. Military satellites are typically placed in high Earth orbit, which is an orbit that is 20,000 to 36,000 kilometers above the Earth’s surface. This orbit allows the satellite to remain in a fixed position relative to the Earth’s surface, which makes it ideal for military purposes.

Reconnaissance satellites are used to gather intelligence information about enemy forces and activities. They can be used to take images of enemy territory, monitor troop movements, and track the development of new weapons systems. Reconnaissance satellites are typically placed in high Earth orbit, which is an orbit that is 20,000 to 36,000 kilometers above the Earth’s surface. This orbit allows the satellite to remain in a fixed position relative to the Earth’s surface, which makes it ideal for military purposes.

Space probes are used to explore The Solar System and beyond. They can be used to study the planets, moons, and other objects in space. Space probes are typically launched on rockets and travel to their destination using their own propulsion systems.

Spy satellites are used to gather intelligence information about enemy forces and activities. They can be used to take images of enemy territory, monitor troop movements, and track the development of new weapons systems. Spy satellites are typically placed in high Earth orbit, which is an orbit that is 20,000 to 36,000 kilometers above the Earth’s surface. This orbit allows the satellite to remain in a fixed position relative to the Earth’s surface, which makes it ideal for military purposes.

Technology demonstration satellites are used to test new technologies in space. They can be used to test new propulsion systems, new materials, and new instruments. Technology demonstration satellites are typically launched on rockets and travel to their destination using their own propulsion systems.

Transfer orbit satellites are used to transport spacecraft from low Earth orbit to higher orbits. They are typically used to transport spacecraft to geostationary orbit or to the International Space Station. Transfer orbit satellites are launched on rockets and use their own propulsion systems to reach their destination.

Space debris is any man-made object that is in orbit around the Earth. It includes defunct satellites, rocket stages, and other pieces of debris. Space debris can pose a hazard to spacecraft, as it can collide with them and cause damage.

Here are some frequently asked questions about satellites, along with short answers:

  1. What is a satellite?
    A satellite is an object that orbits, or circles, a planet or other celestial body.

  2. What are the different types of satellites?
    There are many different types of satellites, but they can be broadly divided into two categories: natural satellites and artificial satellites. Natural satellites are objects that orbit a planet or other celestial body without being launched from Earth. Artificial satellites are objects that are launched from Earth and orbit a planet or other celestial body.

  3. What are some examples of natural satellites?
    The Moon is the Earth’s only natural satellite. Other planets in our solar system also have natural satellites, such as Jupiter’s moons Ganymede and Callisto.

  4. What are some examples of artificial satellites?
    The International Space Station is an example of an artificial satellite. It is a large spacecraft that orbits Earth and serves as a home for astronauts from different countries. Other examples of artificial satellites include weather satellites, communications satellites, and navigation satellites.

  5. What are some of the benefits of satellites?
    Satellites provide many benefits to humans. They are used for communication, navigation, weather forecasting, and scientific research.

  6. What are some of the challenges of satellites?
    Satellites can be expensive to launch and maintain. They can also be vulnerable to damage from space debris and solar storms.

  7. What is the future of satellites?
    Satellites are likely to play an even greater role in our lives in the future. They are being used to develop new technologies, such as self-driving cars and virtual reality. They are also being used to explore new frontiers, such as Mars and the outer reaches of our solar system.

  1. Which of the following is not a type of satellite?
    (A) Communication satellite
    (B) Weather satellite
    (C) Navigation satellite
    (D) Artificial satellite

  2. Which of the following is the most common type of satellite?
    (A) Communication satellite
    (B) Weather satellite
    (C) Navigation satellite
    (D) Artificial satellite

  3. Communication satellites are used for which of the following?
    (A) To provide communication services
    (B) To monitor the weather
    (C) To navigate ships and airplanes
    (D) To study the Earth’s atmosphere

  4. Weather satellites are used for which of the following?
    (A) To provide communication services
    (B) To monitor the weather
    (C) To navigate ships and airplanes
    (D) To study the Earth’s atmosphere

  5. Navigation satellites are used for which of the following?
    (A) To provide communication services
    (B) To monitor the weather
    (C) To navigate ships and airplanes
    (D) To study the Earth’s atmosphere

  6. Artificial satellites are man-made objects that orbit the Earth.
    (A) True
    (B) False

  7. The first artificial satellite was Sputnik 1, which was launched by the Soviet Union in 1957.
    (A) True
    (B) False

  8. There are currently over 2,000 artificial satellites in orbit around the Earth.
    (A) True
    (B) False

  9. Artificial satellites are used for a variety of purposes, including communication, weather monitoring, navigation, and Earth observation.
    (A) True
    (B) False

  10. The International Space Station is an artificial satellite that is used for scientific research.
    (A) True
    (B) False