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RISAT

RISAT (Radar Imaging Satellite) is a series of Indian radar imaging reconnaissance satellites built by the Indian Space Research Organization (ISRO). They provide all-weather surveillance using synthetic aperture radars (SAR).

RISAT
(Radar Imaging Satellite)
Render of Radar Imaging Satellite RISAT-1 in deployed configuration.
ManufacturerISRO
Country of originIndia
OperatorISRO
ApplicationsEarth imaging SAR
Specifications
Launch mass400 kg (880 lb)-2,000 kg (4,400 lb)
PowerUp to 2200 W
BatteriesSolar
EquipmentSynthetic Aperture Radar
RegimeSSO
Production
StatusOperational
Launched6
Operational4
Lost1
Maiden launchRISAT-2 (2009)
Last launchRISAT-1A (2022)

The RISAT series are the first all-weather Earth observation satellites from ISRO. Previous Indian observation satellites relied primarily on optical and spectral sensors which were hampered by cloud cover.

After the 26 November 2008, 2008 Mumbai attacks, the launch plan was modified to launch RISAT-2 before RISAT-1, since the indigenous C-band SAR to be used for RISAT-1 was not ready. RISAT-2 used an Israel Aerospace Industries (IAI) X-band SAR sensor similar to the one employed on TecSAR.

Satellites

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RISAT 2

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Main article: RISAT-2

RISAT-2 was the last of the RISAT series to reach orbit.[1] It was launched successfully on 20 April 2009 at 0015 hours GMT by a PSLV rocket. The 300-kg satellite was built by ISRO using a X-band SAR manufactured by IAI.[2][3][4]

This satellite was fast tracked in the aftermath of the 2008 Mumbai attacks.[5] The satellite will be used for border surveillance, to deter insurgent infiltration and for anti-terrorist operations.[6] It is likely to be placed under the Aerospace Command of the Indian Air Force.[7]

No details of the technical specifications of RISAT-2 have been published. However, it is likely to have a spatial resolution of about a metre or so. Ship detection algorithms for radar satellites of this class are well-known and available. The satellite also has applications in the area of disaster management and agriculture-related activities.[6][8]

RISAT 1

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Main article: RISAT-1

RISAT-1 was an indigenously developed radar imaging satellite successfully launched by a PSLV-XL rocket on 26 April 2012 from Satish Dhawan Space Centre, Shriharikota. RISAT-1 was postponed in order to prioritize the building and launch of RISAT-2.[5][9][10][11]

The features of RISAT-1 include:

  • 160 x 4 Mbit/s data handling system
  • 50 Newton-meter-second reaction wheels
  • SAR antenna deployment mechanism
  • Phased array antenna with dual polarisation

RISAT 2B

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Main article: RISAT-2B

RISAT-2B is an indigenously developed Synthetic Aperture Radar (SAR) imaging satellite operating in X Band with 3.6 m radial rib antenna.[12] It was launched by PSLV C46 (Core Alone) on 22 May 2019 at 0000 (UTC) from First Launch Pad of SDSC (SHAR).[13]

The satellite has the capability to operate in different modes including Very High Resolution RADAR imaging modes of 1m × 0.5m resolution and 0.5m × 0.3m resolution. RISAT-2B is placed in an inclined orbit for better revisit rates over area of interest. Being Radar Imaging satellite, it can image during day / night / all weather conditions. The Satellite will be utilized for high resolution spot imaging of locations of interest.[14][15]

  • Mass: 615 kg[16]
  • Orbit: 557 km (circular) at inclination of 37°[16]
  • Mission life: 5 years[16]

RISAT 2BR1

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Main article: RISAT-2BR1

RISAT-2BR1 is an Indian radar reconnaissance satellite that is part of India's RISAT programme and the fourth satellite in the series. It is built by Indian Space Research Organisation (ISRO). It was launched on 11 December 2019 at 3:25 PM IST on board PSLV rocket from Satish Dhawan Space Centre.[17]

The satellite has resolution of 0.35 meters by which two objects separated by distance of 0.35 metres can be distinctly identified. The mission duration is planned to be 5 years. It is the 50th launch of Polar Satellite Launch Vehicle and 75th launch from Satish Dhawan Space Centre.[18][19]

  • Mass: 628 kg[18]
  • Orbit: 560 km[18]
  • Mission life : 5 years[18]

List of RISAT Satellite

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Designation Resolution (in meters) COSPAR ID NORAD ID Power Launch date, Time (UTC) Launch mass Launch vehicle Launch site Remarks
RISAT-1 1 2012-017A 38248 2200 watts [20] 26 April 2012, 00:17 1,858 kg (4,096 lb) PSLV-XL -C19 SDSC, FLP Equipped with indigenous SAR.
EOS-4/RISAT-1A 2022-013A 51656 2280 watts[21] 14 February 2022, 00:29[22] 1,710 kg (3,770 lb)[22] PSLV-XL C52 SDSC, FLP
RISAT-1B 2024 PSLV-XL SDSC
RISAT-2 Unknown 2009-019A 34807 20 April 2009, 01:15 300 kg (660 lb) PSLV-CA -C12 SDSC, SLP Equipped with Israeli SAR similar to that in TecSAR.
RISAT-2A 2024-25 PSLV-XL SDSC
RISAT-2B 0.5 x 0.3 2019-028A 44233 22 May 2019, 00:00 615 kg (1,356 lb) PSLV-CA -C46 SDSC, FLP
RISAT-2BR1 0.35 2019-089F 44857 11 December 2019, 09:55 628 kg (1,385 lb) PSLV-QL -C48 SDSC, FLP
EOS-01/RISAT-2BR2 2020-081A 46905 7 November 2020, 09:41 630 kg (1,390 lb)[23] PSLV-DL -C49 SDSC, FLP

See also

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References

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  1. ^ "Risat-2 Launched". ASM. Archived from the original on 24 April 2009. Retrieved 22 March 2009.
  2. ^ "India to launch Israel-backed satellite". CNN. 21 March 2009. Retrieved 22 March 2009.
  3. ^ "Home". iai.co.il.
  4. ^ "India set to launch imaging satellite with Israeli support". European Association of Remote Sensing Companies. 23 March 2009. Retrieved 2 January 2023.
  5. ^ a b "The difference between Risat-1 and Risat-2". ASM. Archived from the original on 12 September 2010. Retrieved 25 March 2009.
  6. ^ a b "India to launch spy satellite on April 20". The Times Of India. 8 April 2009.
  7. ^ "Indian Air Force to have independent satellite by 2010 _English_Xinhua". Archived from the original on 16 February 2009. Retrieved 6 April 2009.
  8. ^ "RISAT-2: Spy in the Sky". SP's Aviation. Retrieved 29 April 2023.
  9. ^ "ISRO's New Satellite Could See Through Even Cloudy Sky". Indo Daily. 7 November 2008. Archived from the original on 20 May 2011. Retrieved 21 March 2009.
  10. ^ Launch Info Archived 2009-05-22 at the Wayback Machine
  11. ^ "Earth Observation System". ISRO. Archived from the original on 10 October 2008. Retrieved 21 March 2009.
  12. ^ "RISAT-2B: Radial Rib Antenna - ISRO". www.isro.gov.in. Archived from the original on 29 May 2019. Retrieved 4 July 2019.
  13. ^ "PSLV-C46 successfully launches RISAT-2B - ISRO". www.isro.gov.in. Archived from the original on 28 May 2019. Retrieved 4 July 2019.
  14. ^ "Rajya Sabha Unstarred Question No. 1531 : Earth Observation satellite RISAT-2B" (PDF). 4 July 2019. Retrieved 4 July 2019.
  15. ^ "Earth Observation Satellite RISAT-2B". pib.nic.in. Retrieved 4 July 2019.
  16. ^ a b c "PSLV-C46/RISAT-2B press kit" (PDF). 17 May 2019. Archived from the original (PDF) on 14 December 2020. Retrieved 4 July 2019.
  17. ^ "ISRO's RISAT-2BR1, 9 Other Foreign Satellites Blast Off from Sriharikota". www-news18-com.cdn.ampproject.org. Retrieved 11 December 2019.
  18. ^ a b c d Singh, Surendra (3 December 2019). "Isro to launch another 'eye in the sky' Risat-2BR1 on December 11, will help boost border surveillance". The Times of India. Retrieved 11 December 2019.
  19. ^ IANS (3 December 2019). "ISRO to launch border surveillance satellite Risat-2BR1 on Dec 11". Business Standard India. Retrieved 11 December 2019.
  20. ^ RISAT-1, ISRO. "RISAT-1". isro.gov.in. ISRO. Archived from the original on 16 January 2021. Retrieved 28 October 2020.{{cite web}}: CS1 maint: numeric names: authors list (link)
  21. ^ "PSLV-C52/EOS-04 Brochure - ISRO". www.isro.gov.in. Archived from the original on 9 February 2022. Retrieved 10 February 2022.
  22. ^ a b "PSLV-C52/EOS-04 Mission - ISRO". www.isro.gov.in. Archived from the original on 9 February 2022. Retrieved 10 February 2022.
  23. ^ "Indian PSLV deploys 10 satellites in first launch since start of pandemic". Spaceflight Now. 7 November 2020. Retrieved 7 November 2020.
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