Space Applications in Communication, Meteorology, Agriculture, and Disaster Management is part of Space Technology. Below are notes on 17 sub-topics, followed by practice MCQs from State PSC and UPSC papers.

Sindhu Netra Satellite

Launched in 2021 by DRDO via PSLV-C51 to enhance India's surveillance capability in the Indian Ocean Region (IOR), crucial for maritime security and environmental monitoring. night, all-weather. Examples: Synthetic Aperture Radar (SAR), Lidar.

  • NISAR (NASA-ISRO Synthetic Aperture Radar): Joint mission by NASA and ISRO.
  • NISAR: Low Earth Orbit (LEO) observatory.
  • NISAR: Objective is to launch a dual-frequency (L-band and S-band) Synthetic Aperture Radar (SAR) Earth observation satellite (active sensor).
  • NISAR: Planned launch in 2024.
  • CARTOSAT-1 & 2, RISAT-1 & 3, and SARAL are Earth observation satellites.
  • RISAT series: Utilizes Synthetic Aperture Radar (SAR), an active sensor, for allweather, day/night imaging.
  • SARAL (Satellite with Argos and Altika): Joint ISRO-CNES mission for oceanography.
  • ETRSS-1 (Ethiopian Remote Sensing Satellite-1): Ethiopia's first Earth observation satellite. Launched in 2019.
  • EOS-07: ISRO Earth Observation Satellite.
  • EOS-07: Launched by SSLV-D2 (Small Satellite Launch Vehicle - Developmental Flight 2) from Satish Dhawan Space Centre, Sriharikota.
  • SSLV-D2 mission: Successfully launched EOS-07 along with two co-passenger satellites (AzaadiSAT-2, Janus-1).
  • X-band data transmission: Commonly used in Earth observation satellites for highresolution data.
  • Note: No ISRO Earth Observation Satellite named EOS-08 has been launched by SSLVD3 as of early 2024.

Satellite

Systems:

GPS,

GLONASS, Galileo, NavIC (IRNSS)

  • Navigation Satellite Systems provide Position, Navigation, and Timing (PNT) services.
    • Developed by ISRO (India).
    • NavIC

is the full form of

with

Indian

Constellation.

    • Regional coverage: India and the region extending up to 1500 km from its boundary (primary service area).
    • Constellation of seven satellites in orbit: 3 Geostationary Earth Orbit (GEO) and 4 Geosynchronous Orbit (GSO)/Inclined Geosynchronous Orbit (IGSO).
    • Works in tandem with ground stations.
    • Provides a position accuracy of better than 20 meters in the primary service area.
    • IRNSS-1A spacecraft provides a short message broadcast service (messaging service) to users in the Indian region.
  • Applications of GNSS (e.g., GPS, NavIC) technology

GPS (Global Positioning System)

Developed by the USA. Global coverage. Constellation primarily of MEO satellites (currently ~31 operational).

  • GLONASS

(Globalnaya

Galileo

Developed by the European Union. Global coverage. Constellation of MEO satellites (nominally 24 operational + spares, total 30).

Mobile phone operations

For location-based services, navigation.

Banking operations

Precise timing synchronization for financial transactions, network operations.

Controlling power grids

Synchronization of smart grids and phasor measurement units.

    • Navigation (automotive, aviation, marine), mapping, surveying, precision agriculture, disaster management, scientific research, tracking.

Remote Sensing for Crop Acreage and Yield Estimation

  • EOS-01 is an Earth Observation Satellite launched by ISRO in November 2020.
  • Its primary applications include supporting agriculture, forestry, and disaster management.
  • EOS-01 is not intended for applications like artificial rain generation.

Satellite Communication Systems: DTH, VSAT, Mobile and Internet Connectivity

  • Artificial satellites are used for communication, weather forecasting, and remote sensing.
  • Electromagnetic waves used for satellite communication are primarily radio waves, often in microwave frequency bands (C, Ku, Ka). MF (Medium Frequency) is not used.
  • The orbit commonly used for communication satellites is the Geostationary/Geosynchronous Earth Orbit (GEO).
  • A geostationary satellite is placed at approximately 36,000 km altitude above the Earth's equator.
  • In a geostationary orbit, the satellite's orbital period (approximately 24 hours) matches the Earth's rotation, making it appear stationary to an observer on Earth. Its speed relative to Earth is zero.
  • Geostationary satellites are used for telecommunication, weather monitoring/forecasting, and broadcasting.
  • INSAT (Indian National Satellite System) is an Indian satellite series primarily used for telecommunication systems, TV broadcasting (DTH), weather forecasting, and disaster warning.
  • INSAT-1B was an early satellite that helped cast TV network programmes across the country.
  • ISRO's geostationary INSAT satellites have significantly improved wireless communication systems.
  • DTH (Direct-to-Home) and VSAT (Very Small Aperture Terminal) systems rely on geostationary communication satellites.
  • EDUSAT (GSAT-3) is India's first dedicated satellite for educational services, launched in 2004 as part of the EDUSAT programme.
  • India's Space Programme has made significant progress in resource management, commercializing space, assisting disaster management, weather forecasting, communication, and internal security.
  • India's advanced communication satellite GSAT-8 was launched on May 21, 2011, from Kourou (French Guiana).
  • Major solar storms (solar flares) reaching Earth can cause:
    • GPS and navigation system failures.
    • Damage to power grids.
    • Intense auroras.
    • Disturbance of satellite orbits.
    • Interruption of shortwave radio communication for aircraft over polar regions.
  • Solar storms are NOT known to directly cause tsunamis or widespread forest fires.

INSAT Series

Indian National Satellite System. Multipurpose geostationary satellites providing

5. Space Debris, Space Law, and Outer Space Governance

meteorology, and search & rescue.

  • KALPANA-1 (originally METSAT) India's first *exclusive* meteorological satellite.

KALPANA-1 Launch

Launched in September 2002.

KALPANA-1 Renaming

Renamed in 2003 in memory of Kalpana Chawla.

PSLV-C4

The launch vehicle for METSAT (KALPANA-1). This was the first PSLV mission to inject a satellite (payload 1060 kg, i.e., >1000 kg) into a Geosynchronous Transfer Orbit (GTO).

Satellite Applications

Provide crucial information for weather forecasting (tracking advancing storms, cyclones, monsoons), climate modeling, and Earth resource monitoring (forest/vegetative cover, rivers and their courses, ocean parameters, land use).

Practice MCQs: Space Applications in Communication, Meteorology, Agriculture, and Disaster Management

Environmental Monitoring: Pollution, Ozone Layer, Urban Heat Islands

  1. In the year 2021, DRDO launched which satellite by PSLV-C51 to enhance India's surveillance capability in the Indian Ocean Region (IOR)?

    Asked in: GS JE PHE 29 2023 2407 2024

    1. Satish Dhawan Satellite
    2. Sindhu Netra Satellite
    3. Sri Shakti Satellite
    4. Sindhu Durga Satellite
    Show answer

    Answer: B. Sindhu Netra Satellite

    The Sindhu Netra Satellite, launched by DRDO in 2021 via PSLV-C51, was specifically deployed to bolster India's surveillance capabilities in the Indian Ocean Region.

  2. Consider the following statements regarding launching of Earth Observation Satellite EOS-08 and choose the correct option regarding it: Statement - A : It is launched by SSLV-D3 from Satish Dhawan Space Centre, Shriharikota. Statement - B : EOS-08 carries two payloads. Statement - C : X band data transmission has been used in EOS-08. - (5) Question not attempted

    Asked in: School Lecturer (Sanskrit Edu.) 2024

    1. All the three statements are true.
    2. Statement A and B are true but Statement C is false.
    3. Statement B and C are true but Statement A is false.
    4. Statement A and C are true but Statement B is false.
    Show answer

    Answer: A. All the three statements are true.

    This question tests knowledge about specific Indian space missions, including the launch vehicle, launch site, payloads, and technological features of a satellite.

  1. Full form of NavIC is :

    Asked in: CGPSC Prelims Exam 2021

    1. Navigation without International Control
    2. Navigation with Indian Constellation
    3. Navigation with Indian Coastal
    4. Navigation with Indian Cooperation
    Show answer

    Answer: B. Navigation with Indian Constellation

    - NavIC is India's independent regional navigation satellite system. - It is designed to provide accurate position information service to users in India and the region extending up to 1,500 km from its boundary.

  2. Which of the following statements are correct regarding Indian Regional Navigation Satellite System (IRNSS) : NavIC? 1. It is designed to provide accurate position information service to users in India as well as the region extending up to 1500 km from its boundary 2. The IRNSS System is expected to provide a position accuracy of better than 20 meters in the primary service area. 3. IRNSS-1A spacecraft provides messaging service to users in the Indian region.

    Asked in: GPSC Prelims CSP 2 2022

    1. 1, 2 and 3
    2. 2 and 3 only
    3. 1 and 3 only
    4. 1 and 2 only
    Show answer

    Answer: A. 1, 2 and 3

    - Statement 1 is correct. The Indian Regional Navigation Satellite System (IRNSS), officially named NavIC (Navigation with Indian Constellation), is an independent regional navigation satellite system developed by ISRO. It is designed to provide accurate real-time positioning, navigation, and timing services primarily to users in India and the region extending up to 1500 km from its national boundary. - Statement 2 is correct. NavIC is designed to provide a position accuracy of better than 20 meters in the primary service area and better than 10 meters in specific applications like the Precise Service. - Statement 3 is correct. IRNSS-1A was the first of the planned seven satellites in the NavIC constellation. Besides the standard navigation payload, it carried a C-band transponder for ranging and a messaging payload for providing disaster management and other specialized services.

  3. In which of the following areas can GPS technology be used ? 1. Mobile phone operations 2. Banking operations 3. Controlling the power grids Select the correct answer using the code given below :

    Asked in: UPSC IAS 2018

    1. 1 only
    2. 2 and 3 only
    3. 1 and 3 only
    4. 1, 2 and 3
    Show answer

    Answer: D. 1, 2 and 3

    GPS (Global Positioning System) provides precise location and time information, which has applications across numerous sectors.

  4. The Navigation with Indian Constellation (NavIC) is a regional navigation satellite system developed by ISRO that is a

    Asked in: Insp Stat GK 04 2023

    1. geostationary satellite that works in direct link with strategic ground stations
    2. constellation of seven satellites in orbit that works in tandem with ground stations
    3. low earth orbit satellite which is used for remote sensing, high-resolution earth observation, scientific research, as data can be acquired and transmitted rapidly
    4. None of the above
    Show answer

    Answer: B. constellation of seven satellites in orbit that works in tandem with ground stations

    NavIC is ISRO's own regional navigation satellite system. It consists of a constellation of seven satellites. It is designed to provide PNT (Positioning, Navigation, and Timing) services in the Indian subcontinent and surrounding regions.

Remote Sensing for Crop Acreage and Yield Estimation

  1. ________ is an Earth observation satellite launched by ISRO in November 2020 to support applications in agriculture and forestry and disaster management.

    Asked in: GPSC Prelims CSP 2 2021

    1. EOS-01 Satellite
    2. DMS-01 Satellite
    3. AFDM-01 Satellite
    4. None of the above
    Show answer

    Answer: A. EOS-01 Satellite

    EOS-01 is an Indian Earth observation satellite launched by the Indian Space Research Organisation (ISRO) on November 7, 2020. It was the first satellite launched by ISRO after the COVID-19 lockdown.

  2. EOS-01 is an earth observation satellite and is NOT intended for application in

    Asked in: UPPSC ACF RFO gs 2 2021

    1. Agriculture
    2. Forestry
    3. Disaster management support
    4. Artificial rains
    Show answer

    Answer: D. Artificial rains

    EOS-01 (Earth Observation Satellite-01) is an advanced earth observation satellite developed by ISRO. Its primary applications include agriculture, forestry, and disaster management support. It provides multi-spectral imagery that aids in monitoring natural resources, assessing crop health, mapping forest cover, and providing crucial data during natural calamities like floods, cyclones, and droughts.

Satellite Communication Systems: DTH, VSAT, Mobile and Internet Connectivity

  1. Which of the following satellites helps to cast TV network programmes all over the country?

    Asked in: APSC CCE Prelims Exam 2014

    1. Aryabhatta
    2. APPLE
    3. Rohini
    4. INSAT-1B
    Show answer

    Answer: D. INSAT-1B

    The INSAT (Indian National Satellite System) series of satellites are multi-purpose geostationary satellites used for telecommunications, broadcasting, meteorology, and search and rescue operations. INSAT-1B was one of the early satellites in this operational series that facilitated nationwide TV network programmes.

  2. In which year was the EDUSAT programme launched?

    Asked in: APSC CCE Prelims Exam 2015

    1. 2005
    2. 2000
    3. 1998
    4. 2004
    Show answer

    Answer: D. 2004

    EDUSAT was designed to provide satellite-based interactive distance education to schools, colleges, and higher educational institutions across India.

  3. The electromagnetic waves, which are used for satellite communication, are

    Asked in: UPSC CDS 1 2020

    1. infrared radiations
    2. ultraviolet radiations
    3. radio waves
    4. visible lights
    Show answer

    Answer: C. radio waves

    Infrared radiation is used for shorter-range communication like remote controls or fiber optics but is not suitable for long-distance satellite communication due to atmospheric absorption. Ultraviolet radiation is largely absorbed by the atmosphere and is not used for this purpose. Visible light is also affected by atmospheric conditions (clouds, scattering) and is generally not used for long-distance space communication, although optical communication with satellites is an emerging technology. Radio waves/microwaves are the standard for current satellite communication systems.

  4. What has the geostationary satellite INSAT put in orbit by ISRO India improved ?

    Asked in: MPSC CS Prelims 2012

    1. Geological survey
    2. Highway systems
    3. Wireless Communication systems
    4. River systems
    Show answer

    Answer: C. Wireless Communication systems

    INSAT (Indian National Satellite System) is a series of multi-purpose geostationary satellites built and launched by ISRO to satisfy the telecommunications, broadcasting, meteorology, and search and rescue needs of India. Geostationary satellites are positioned above the same point on Earth, making them ideal for continuous communication and broadcasting services.

  5. Consider the following statements : (a) The speed of telecommunication satellite relative to earth is zero. (b) Hence it appears to be stationary to a person on the earth.

    Asked in: MPSC CS Prelims 2020

    1. Both statements are false
    2. (a) is true and is a reason of (b)
    3. (a) is true and is not a reason of (b)
    4. (a) is correct, (b) is not
    Show answer

    Answer: B. (a) is true and is a reason of (b)

    - Geostationary satellites have zero relative speed with respect to a point on the Earth's surface directly below them. - This zero relative speed makes them appear stationary from Earth.

  6. Which of the following is used for communication, weather forecasting and remote sensing ?

    Asked in: OPSC CS Prelims 2016

    1. Natural satellites
    2. Artificial satellites
    3. Space shuttles
    4. Supper computers
    Show answer

    Answer: B. Artificial satellites

    Artificial satellites are key technological assets enabling modern global communication, environmental monitoring, and data collection from space.

  7. Which of the following frequency bands is not used in INSAT/GSAT satellite communication?

    Asked in: RPSC RAS Prelims 2021

    1. Ka
    2. C
    3. MF
    4. Ku
    Show answer

    Answer: C. MF

    - INSAT/GSAT satellites are geostationary satellites used for communication and broadcasting. - These satellites primarily operate in higher frequency bands like C-band, Extended C-band, Ku-band, and Ka-band due to their capacity for large bandwidth and smaller antenna sizes at ground stations. - The MF band is part of the radio spectrum (300 kHz to 3 MHz) and is primarily used for AM radio broadcasting, maritime communication, and navigational beacons, not for high-frequency satellite links like those used by INSAT/GSAT.

  8. Indian Satellite series which is being used for telecommunication system is

    Asked in: UKPSC CS Prelims 2016

    1. Rohini
    2. I.R.S.
    3. CARTOSAT
    4. INSAT
    Show answer

    Answer: D. INSAT

    - The INSAT (Indian National Satellite System) series is a multi-purpose geostationary satellite system developed by ISRO. - These satellites are primarily used for telecommunications (including telephony, VSAT, etc.), broadcasting (TV, DTH), meteorology, and satellite-based search and rescue services.

  9. If a major solar storm (solar flare) reaches the Earth, which of the following are the possible effects on the Earth? GPS and navigation systems could fail. Tsunamis could occur at equatorial regions. Power grids could be damaged. Intense auroras could occur over much of the Earth. Forest fires could take place over much of the planet. Orbits of the satellites could be disturbed. Shortwave radio communication of the aircraft flying over polar regions could be interrupted. Select the correct answer using the code given below :

    Asked in: UPSC IAS 2022

    1. 1, 2, 4 and 5 only
    2. 2, 3, 5, 6 and 7 only
    3. 1, 3, 4, 6 and 7 only
    4. 1, 2, 3, 4, 5, 6 and 7
    Show answer

    Answer: C. 1, 3, 4, 6 and 7 only

    - Statement 1 (GPS): Correct. Solar storms can disrupt the ionosphere, through which GPS signals pass, causing navigation errors or outages. - Statement 2 (Tsunamis): Incorrect. Solar storms affect the space environment around Earth and the upper atmosphere, not geological processes that cause tsunamis. - Statement 3 (Power grids): Correct. Geomagnetic storms can induce currents in long conductors like power lines, potentially damaging transformers and causing blackouts. - Statement 4 (Auroras): Correct. Increased particle influx from solar storms enhances auroral displays, making them more intense and visible at lower latitudes than usual. - Statement 5 (Forest fires): Incorrect. There is no direct link between solar storms and the ignition or spread of forest fires. - Statement 6 (Satellite orbits): Correct. Increased heating of the upper atmosphere by particle influx causes it to expand, increasing drag on satellites in Low Earth Orbit (LEO) and affecting their trajectories. - Statement 7 (Shortwave radio): Correct. Shortwave radio relies on reflection from the ionosphere. Solar storms can cause ionospheric disturbances (radio blackouts), especially affecting high- latitude regions where aircraft often use shortwave communication.

  10. India's advanced communication satellite GSAT-8 was launched on May 21, 2011 from

    Asked in: UPPSC Upper Mains 2010

    1. Hassan
    2. Kourou
    3. Sriharikota
    4. Thiruvananthapuram
    Show answer

    Answer: B. Kourou

    GSAT-8 was a geostationary communication satellite built by ISRO. Due to its heavy weight (over 3 tonnes), it was launched by the European Ariane 5 rocket, as ISRO's GSLV at the time did not have the capacity for such heavy payloads to GTO.

  11. The orbit commonly used for communication satellite is

    Asked in: JUNIOR ACCOUNTANT AND TRA 2013

    1. polar orbit
    2. sun synchronous orbit
    3. geo-synchronous orbit
    4. any of these
    Show answer

    Answer: C. geo-synchronous orbit

    Geo-synchronous orbit is commonly used for communication satellites.

  12. Which of the following is a type of orbit used by communication satellites that allows them to remain in a fixed position relative to the Earth's surface?

    Asked in: Local Self Government Dept. Exam 2022

    1. Low Earth Orbit
    2. Geostationary Orbit
    3. Polar Orbit
    4. Sun Synchronous Orbit
    Show answer

    Answer: B. Geostationary Orbit

    Geostationary Orbit allows communication satellites to maintain a constant position over a specific point on Earth, facilitating uninterrupted signal transmission.

  13. India's first dedicated satellite for educational services –

    Asked in: School Lecturer (Sanskrit Edu.) 2018

    1. (1) KALAM SAT-V
    2. (2) PRATHAM
    3. (3) SWAYAM-I
    4. (4) EDUSAT
    Show answer

    Answer: D. (4) EDUSAT

    Recalling India's pioneering efforts in using space technology for education.

  14. The twin objectives of India's Space programme are-discovery and exploration and research and education related to Space Science. Now, keeping in view the above mentioned objectives, in which of the following areas India's Space programme has made significant progress?

    Asked in: ARO GS 252022 74 2024

    1. Resource management
    2. Commercializing space programme and assisting disaster management
    3. Weather forecasting, communication, internal security and combating terrorism
    4. All of the above
    Show answer

    Answer: D. All of the above

    India's Space programme, spearheaded by ISRO (Indian Space Research Organisation), has a broad mandate that includes scientific discovery, exploration, and research. The programme has achieved remarkable success in various application-oriented areas: Resource Management Utilizing satellite data for mapping natural resources (minerals, water, forests), agricultural monitoring, and land use planning. Commercializing Space Programme and Assisting Disaster Management India has successfully commercialized its launch vehicle capabilities (e.g., PSLV) and satellite manufacturing. ISRO's satellites play a crucial role in disaster monitoring, early warning systems (cyclones, floods), and communication during emergencies. Weather Forecasting, Communication, Internal Security, and Combating Terrorism Satellites like INSAT and GSAT provide vital services for weather forecasting, telecommunications, broadcasting, navigation, and surveillance. Earth observation satellites are used for border surveillance, mapping for internal security, and intelligence gathering relevant to combating terrorism.Since significant progress has been made in all these distinct areas, option D is the most comprehensive and correct answer.

  15. An artificial satellite placed in a geosynchronous object is used for

    Asked in: Civil Engg GA 24 2023 CO 1505 2024

    1. telecommunication and weather monitoring
    2. telecommunication and atmospheric remote sensing
    3. surveillance and mineral exploration
    4. GPS and surveillance
    Show answer

    Answer: A. telecommunication and weather monitoring

    Geosynchronous/geostationary satellites are primarily used for telecommunication and weather monitoring due to their fixed position relative to Earth.

  16. At what altitude above the earth is a geostationary communications satellite placed and why?

    Asked in: Paper I Part II General Knowledege AAO APDCL

    1. At 36000 km because from this height most of the earth's surface is covered.
    2. At 36000 km because its revolution around the earth coincides with the rotation of the earth.
    3. At 24000 km because its revolution coincides with the rotation of the earth.
    4. At 24000 km because loss of signal is minim‐ um at this distance for communication.
    Show answer

    Answer: B. At 36000 km because its revolution around the earth coincides with the rotation of the earth.

    Geostationary satellites are placed at 36,000 km altitude because their revolution around the Earth coincides with the Earth's rotation.

Satellite-based Weather Forecasting and Climate Modeling

  1. Which is the first in the series of Exclusive Meteorological Satellites of India ?

    Asked in: GPSC Prelims CSP 2 2017

    1. INSAT-2
    2. GSAT-18
    3. GSAT-10
    4. KALPANA-1
    Show answer

    Answer: D. KALPANA-1

    Unlike the earlier INSAT series satellites which were multi-purpose (carrying payloads for communication, broadcasting, and meteorology), KALPANA-1 was solely dedicated to meteorological observations.

  2. Indian Satellite Series 'INSAT' is an example of :

    Asked in: JPSC CS Prelims 2021

    1. Meteorological Satellite
    2. Resource Satellite
    3. Military Satellite
    4. Polar orbiting Satellite
    Show answer

    Answer: A. Meteorological Satellite

    The Indian National Satellite (INSAT) system is a series of multipurpose geostationary satellites used for telecommunications, broadcasting, and meteorology. Meteorology is a primary and continuous application of the INSAT series.