RISAT

{{Infobox spacecraft class

| name = RISAT
(Radar Imaging Satellite)

| image = Render of Radar Imaging Satellite RISAT-1 in deployed configuration.png

| caption = Render of Radar Imaging Satellite RISAT-1 in deployed configuration.

| image_size = 290px

| manufacturer = ISRO

| country = India

| operator = ISRO

| lifetime =

| bus =

| applications = Earth imaging SAR

| orbit_reference = Geocentric orbit

| orbits = SSO

| status = Operational

| launched = 6

| operational = 4

| failed =

| lost = 1

| first = RISAT-2 (2009)

| last = RISAT-1A (2022)

| retired =

| mass = {{cvt|400|kg}}-{{cvt|2000|kg}}

| power = Up to 2200 W

| batteries = Solar

| equipment = Synthetic Aperture Radar

}}

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).

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

= RISAT 2 =

RISAT-2 was the last of the RISAT series to reach orbit.{{cite web|url=http://www.asmmag.com/news/risat-2-launched|title=Risat-2 Launched|publisher=ASM|access-date=2009-03-22|url-status=dead|archive-url=https://web.archive.org/web/20090424210905/http://www.asmmag.com/news/risat-2-launched|archive-date=2009-04-24}} 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.{{cite news|url=http://edition.cnn.com/2009/WORLD/asiapcf/03/21/india.satellite/|title=India to launch Israel-backed satellite|publisher=CNN|access-date=2009-03-22 | date=2009-03-21}}{{cite web |url=http://www.iai.co.il/ |title=Home |website=iai.co.il}}{{cite news|url=https://earsc.org/2009/03/23/india-set-to-launch-imaging-satellite-with-israeli-support/ |title=India set to launch imaging satellite with Israeli support |date=23 Mar 2009 |publisher=European Association of Remote Sensing Companies|access-date=2 Jan 2023 }}

This satellite was fast tracked in the aftermath of the 2008 Mumbai attacks.{{cite web|url=http://www.asmmag.com/news/india-to-launch-risat|title=The difference between Risat-1 and Risat-2|publisher=ASM|access-date=2009-03-25|url-status=dead|archive-url=https://web.archive.org/web/20100912231400/http://www.asmmag.com/news/india-to-launch-risat|archive-date=2010-09-12}} The satellite will be used for border surveillance, to deter insurgent infiltration and for anti-terrorist operations.{{cite news| url=http://timesofindia.indiatimes.com/articleshow/4374544.cms | work=The Times Of India | title=India to launch spy satellite on April 20 | date=2009-04-08}} It is likely to be placed under the Aerospace Command of the Indian Air Force.{{cite web |url=http://news.xinhuanet.com/english/2009-02/13/content_10815093.htm |title=Indian Air Force to have independent satellite by 2010 _English_Xinhua |access-date=2009-04-06 |url-status=dead |archive-url=https://web.archive.org/web/20090216113933/http://news.xinhuanet.com/english/2009-02/13/content_10815093.htm |archive-date=2009-02-16 }}

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.{{cite web|title=RISAT-2: Spy in the Sky|url=https://www.sps-aviation.com/story/?id=279|publisher=SP's Aviation|access-date=April 29, 2023}}

= 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.{{cite news|url=http://www.indodaily.com/reports/ISRO_New_Satellite_Could_See_Through_Even_Cloudy_Sky_999.html|title=ISRO's New Satellite Could See Through Even Cloudy Sky|date=7 November 2008|publisher=Indo Daily|access-date=2009-03-21|url-status=dead|archive-url=https://web.archive.org/web/20110520224119/http://www.indodaily.com/reports/ISRO_New_Satellite_Could_See_Through_Even_Cloudy_Sky_999.html|archive-date=20 May 2011}}[http://www.spacemart.com/reports/RISAT_Is_A_Home_Grown_Satellite_999.html Launch Info] {{webarchive|url=https://web.archive.org/web/20090522181615/http://www.spacemart.com/reports/RISAT_Is_A_Home_Grown_Satellite_999.html |date=2009-05-22 }}{{cite web|url=http://www.isro.gov.in/rep2005/EOS.htm |title=Earth Observation System |publisher=ISRO |access-date=2009-03-21 |url-status=dead |archive-url=https://web.archive.org/web/20081010150300/http://www.isro.gov.in/rep2005/EOS.htm |archive-date=10 October 2008 }}

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 =

RISAT-2B is an indigenously developed Synthetic Aperture Radar (SAR) imaging satellite operating in X Band with 3.6 m radial rib antenna.{{Cite web|url=https://www.isro.gov.in/update/22-may-2019/risat-2b-radial-rib-antenna|title=RISAT-2B: Radial Rib Antenna - ISRO|website=www.isro.gov.in|access-date=2019-07-04|archive-date=29 May 2019|archive-url=https://web.archive.org/web/20190529104039/https://www.isro.gov.in/update/22-may-2019/risat-2b-radial-rib-antenna|url-status=dead}} It was launched by PSLV C46 (Core Alone) on 22 May 2019 at 0000 (UTC) from First Launch Pad of SDSC (SHAR).{{Cite web|url=https://www.isro.gov.in/update/22-may-2019/pslv-c46-successfully-launches-risat-2b|title=PSLV-C46 successfully launches RISAT-2B - ISRO|website=www.isro.gov.in|access-date=2019-07-04|archive-date=28 May 2019|archive-url=https://web.archive.org/web/20190528045558/https://www.isro.gov.in/update/22-may-2019/pslv-c46-successfully-launches-risat-2b|url-status=dead}}

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.{{Cite web|url=http://164.100.158.235/question/annex/249/Au1531.pdf|title=Rajya Sabha Unstarred Question No. 1531 : Earth Observation satellite RISAT-2B|date=4 July 2019|access-date=4 July 2019}}{{Cite web|url=http://pib.nic.in/newsite/PrintRelease.aspx?relid=191250|title=Earth Observation Satellite RISAT-2B|website=pib.nic.in|access-date=2019-07-04}}

Mass: 615 kg{{Cite web|url=https://www.isro.gov.in/sites/default/files/flipping_book/pslv-c46_risat2b_launch_kit/PSLV-C46_RISAT2B_launch_kit/files/assets/common/downloads/PSLV-C46%20RISAT2B%20launch%20kit.pdf|title=PSLV-C46/RISAT-2B press kit|date=17 May 2019|access-date=4 July 2019|archive-date=14 December 2020|archive-url=https://web.archive.org/web/20201214225900/https://www.isro.gov.in/sites/default/files/flipping_book/pslv-c46_risat2b_launch_kit/PSLV-C46_RISAT2B_launch_kit/files/assets/common/downloads/PSLV-C46%20RISAT2B%20launch%20kit.pdf|url-status=dead}}
Orbit: 557 km (circular) at inclination of 37°
Mission life: 5 years

= 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.{{Cite web|url=https://www-news18-com.cdn.ampproject.org/v/s/www.news18.com/amp/news/india/with-few-hours-left-for-launch-of-isros-risat-2br1-heres-all-you-need-to-know-about-the-spy-satellite-2419867.html?usqp=mq331AQCKAE=&_js_v=0.1|title=ISRO's RISAT-2BR1, 9 Other Foreign Satellites Blast Off from Sriharikota|website=www-news18-com.cdn.ampproject.org|access-date=2019-12-11}}

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.{{Cite web|url=https://timesofindia.indiatimes.com/india/isro-to-launch-another-eye-in-the-sky-risat-2br1-on-dec-11-will-help-boost-border-surveillance/articleshow/72340281.cms|title=Isro to launch another 'eye in the sky' Risat-2BR1 on December 11, will help boost border surveillance|date=3 December 2019|first=Surendra|last=Singh|website=The Times of India|language=en|access-date=2019-12-11}}{{Cite news|url=https://www.business-standard.com/article/current-affairs/isro-to-launch-border-surveillance-satellite-risat-2br1-on-dec-11-119120301040_1.html|title=ISRO to launch border surveillance satellite Risat-2BR1 on Dec 11|last=IANS|date=2019-12-03|work=Business Standard India|access-date=2019-12-11}}

Mass: 628 kg
Orbit: 560 km
Mission life : 5 years

List of RISAT Satellite

class="wikitable sortable"

! 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 {{cite web|last1=RISAT-1|first1=ISRO|title=RISAT-1|url=https://www.isro.gov.in/Spacecraft/risat-1|website=isro.gov.in|publisher=ISRO|access-date=28 October 2020|archive-date=16 January 2021|archive-url=https://web.archive.org/web/20210116221615/https://www.isro.gov.in/Spacecraft/risat-1|url-status=dead}}

| 26 April 2012, 00:17

| {{cvt|1858|kg}}

| PSLV-XL -C19

| SDSC, FLP

| Equipped with indigenous SAR.

EOS-04/RISAT-1A

| 2022-013A

| 51656

| 2280 watts{{Cite web|title=PSLV-C52/EOS-04 Brochure - ISRO|url=https://www.isro.gov.in/pslv-c52-eos-04-mission/pslv-c52-eos-04-brochure|access-date=2022-02-10|website=www.isro.gov.in|archive-date=9 February 2022|archive-url=https://web.archive.org/web/20220209140030/https://www.isro.gov.in/pslv-c52-eos-04-mission/pslv-c52-eos-04-brochure|url-status=dead}}

| 14 February 2022, 00:29{{Cite web|title=PSLV-C52/EOS-04 Mission - ISRO|url=https://www.isro.gov.in/launcher/pslv-c52-eos-04-mission|access-date=2022-02-10|website=www.isro.gov.in|archive-date=9 February 2022|archive-url=https://web.archive.org/web/20220209012447/https://www.isro.gov.in/launcher/pslv-c52-eos-04-mission|url-status=dead}}

| {{cvt|1710|kg}}

| PSLV-XL -C52

| SDSC, FLP

EOS-09/RISAT-1B

| 18 May 2025, 00:00-04:00

| PSLV-XL -C61

| SDSC

RISAT-2

| Unknown

| 2009-019A

| 34807

| 20 April 2009, 01:15

| {{cvt|300|kg}}

| 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

| {{cvt|615|kg}}

| PSLV-CA -C46

| SDSC, FLP

RISAT-2BR1

| 0.35

| 2019-089F

| 44857

| 11 December 2019, 09:55

| {{cvt|628|kg}}

| PSLV-QL -C48

| SDSC, FLP

EOS-01/RISAT-2BR2

| 2020-081A

| 46905

| 7 November 2020, 09:41

| {{cvt|630|kg}}{{cite news|url=https://spaceflightnow.com/2020/11/07/indian-pslv-deploys-10-satellites-in-first-launch-since-start-of-pandemic/|title=Indian PSLV deploys 10 satellites in first launch since start of pandemic|publisher=Spaceflight Now|date=7 November 2020|access-date=7 November 2020}}

| PSLV-DL -C49

| SDSC, FLP

RISAT-3

| 2027

| {{cite news|url=https://spaceflightnow.com/2020/11/07/indian-pslv-deploys-10-satellites-in-first-launch-since-start-of-pandemic/|title=Indian PSLV deploys 10 satellites in first launch since start of pandemic|publisher=Spaceflight Now|date=7 November 2020|access-date=7 November 2020}}

| PSLV

| SDSC