Bhaskara series
| Satellite | Configuration: Orbit and LV | Significance | Application |
| Bhaskara 1 and 2 | Imaging satellites LEO-Polar Orbit 534 km LV: Russian LV Kosmos | 1st earth observation satellite | Observation of hydrology, forestry, geology and ocean-surface. |
| IRS 1A | 1st full-fledged earth observation satellite |
Operational EOS of India
Following are the earth observation satellites that are currently operational in India
- 14 in SSPO (Resourcesat-2; Cartosat-1, 2, 2A and 2B; Risat-1 and 2, 2B, 2BR 1, 2BR2(EOS-01), 1B(EOS-04); Oceansat 2, SARAL, OceanSat 3(Nov 2022).
- 3 in GEO (INSAT-3D, Kalpana-1 and INSAT BA)
- 1 in equatorial orbit (Megha-Tropiques).
RISAT series
- Radar imaging satellite series with resolution less than 1 m
- Active remote sensing satellite: beam a radio signal on the earth’s surface and ‘senses’ the radio signal reflected back giving them all-weather and day-and-night observing capability.
- ISRO has launched 7 satellites in the RISAT series so far. Risat-2A is yet to be launched.
- Applications: Agriculture, forestry, soil moisture, geology, sea ice, coastal monitoring, object identification, flood monitoring and military surveillance.
| RISAT series | Satellite name | Significance |
| RISAT 2 series | RISAT 2 RISAT-2A(planned for December 2023 launch) RISAT 2B RISAT 2BR 1 RISAT 2BR 2 (now called EOS-01) | RISAT 2: India's first dedicated reconnaissance satellite to monitor India's borders against infiltration and support anti-terror operations Launched in the aftermath of 26/11 Mumbai terror attack SAR equipment from Israel RISAT 2B: Stepping up C4ISR security architecture (Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance) RISAT-2BR1: Agriculture, forestry and disaster management RISAT 2BR2: (called EOS 01) |
| RISAT 1 series | RISAT 1 RISAT-1A RISAT-1B(EOS-04) | Assisted planning of the 2016 surgical strike (response to Uri terror attack) along with Cartosat-2 Status RISAT-1A and 1B (now called EOS-04) are follow-on successors of RISAT 1 |
CARTOSAT series
- Remote sensing satellite dedicated to cartographic applications.
- Earlier versions were panchromatic (senses visible light across all colours, violet to red). Cartosat-2C onwards multi-spectral scanners are used and Cartosat 3 has a hyperspectral scanner.
- General applications: Cartography for large scale urban planning, rural resource and infrastructure development, Land Information System and GIS application, coastal land use etc.
| Cartosat-1 | Panchromatic scanner 2.5 m resolution | |
| Cartosat-2 | 2, 2A, 2B, 2C, 2D, 2E,2F | Panchromatic, multispectral scanner less than 1 m resolution Swath of 10 km Revisit period: every 4 days |
| Cartosat-3 | 3, 3A, 3B(EOS-08): to be launched | Hyperspectral sensors used 0.25 m resolution (best in the world) 16 Km swath |
ResourceSat series
- Natural resource monitoring satellites
- Medium resolution, wide swath satellites with multispectral scanners
- Applications: Advanced land and water resource management applications.
| ResourceSAT 1 | |
| ResourceSAT 2 | 2, 2A |
| ResourceSAT 3 | 3, 3A, 3B |
| ResourceSAT 3S | 3S and 3SA Stereographic imaging: 3-d images for depth |
OceanSAT series
- Dedicated EO satellite for ocean monitoring.
- Multispectral microwave sensor to measure sea surface temperature, wind speed, cloud water content and water vapour content in the atmosphere above the ocean.
- Application: Study of chlorophyll concentration, phytoplankton blooms, atmospheric aerosols and suspended sediments in the water.
- Includes OceanSAT 1, 2, and 3 and 3A.
- OceanSAT 3(named EOS-06) was launched in November 2022.
GiSat series: Geo-imaging satellites
- 1st among remote-sensing satellite in geosynchronous orbit. (normally they are in SSPO)
Status
- GiSat-1(EOS-03) launch in 2021 failed
- GiSat-2(EOS-05) is a dedicated military satellite to be acquired by Indian Navy. Launch date to be decided.
Significance
- Currently imaging satellites map a particular area only once in 22 days. GiSat can scan or map an area every 2nd day as it will be placed in geostationary orbit.
EOS Series
| Name | Configuration: Orbit and LV | Significance | Application |
| EOS-01 RISAT-2BR2 | LV: PSLV Orbit: SSPO | Agriculture, forestry and disaster management support | |
| EOS-02 | LV: SSLV Orbit: Significance 1st launch of SSLV Microsatellite imaging satellite with a short turn-around time Function: geo-environmental studies, forestry, hydrology, agriculture, soil, coastal studies, etc. | geo-environmental studies, forestry, hydrology, agriculture, soil, coastal studie | |
| EOS-03 GISAT-1 | Des: Geo-Imaging Satellite LV: GSLV Orbit: GTO-to-GSO Status Failed | Quick monitoring of natural hazards like cyclone monitoring, cloud burst and thunderstorm monitoring and providing disaster warning.Continuous observation of Indian sub-continent for Agriculture, forestry, water bodies | |
| EOS-04 | Risat Radar Imaging Satellite LV: PSLV Orbit: SSPO | All weather monitoring for Agriculture, Forestry and Plantations, Flood Mapping, Soil Moisture & Hydrology. | |
| EOS-05 GISAT-2 | Geo-Imaging Satellite LV: GSLV MkII Orbit: GSO Status To be decided | Military satellite dedicated to Indian Navy | |
| EOS-06 Ocean Sat-3 | OceanSat-3 LV: PSLV Orbit: SSPO Significance Chlorophyll, Sea Surface Temperatures, wind speed and land based geophysical parameters. Instruments Ocean Colour Monitor Sea Surface Temperature Monitor (SSTM) Sensors Ku-Band Scatterometer (SCAT-3) ARGOS (data collection system) | Monitors the biological parameters of the ocean | Identify potential fishing zones, weather forecasting, wind velocity and cyclone detection, cyclone tracking and maritime security. |
| EOS-07 | Microsatellite LV: SSLV (1st successful launch) Orbit: | Significance Landmark 1st successful launch of SSLV | |
| EOS-08 | Cartosat 3 (to be launched) |
Other Important Remote Sensing Satellites
HysIS: Hyspectral Imaging Satellite
- 1st hyperspectral imaging satellite.
- It observes earth’s surface in 3 different ranges including visible, near infrared and shortwave infrared regions in 55 spectral or colour bands.
- Enables us to do a ‘CATSCAN’ equivalent of Earth surface.
- Application
- Agriculture, forestry, coastal zones, inland waters, soil, oil and minerals mapping and military surveillance
Hyperspectral Imaging v/s Multi-Spectral Imaging: Concept
- We have seen the basics of spectroscopy in previous section.
- Multi-spectral scanners include sensors capable of detecting absorption, emission and scattering (reflection and refraction) of different lights (visible and invisible). Doing this gives more details about the object and thereby help in differentiating between chemical composition.
- Hyperspectral imaging is an advanced version of multi-spectral imaging. Only difference is it includes sensors capable of sensing a contiguous band of light thereby giving sharp details.
- While multispectral scanners are useful to differentiate minerals, hyperspectral sensors help in even quantifying individual materials.
NISAR
Planned launch: late-2023 early-2024
- Joint active remote sensing satellite of NASA-ISRO, thus all-weather, day-and-night, cloud penetrating.
- Short for NASA-ISRO Synthetic Aperture Radar satellite
- 2 radar frequencies (S band and L band)
- Uses advanced technique called interferometric synthetic aperture radar (InSAR)
- InSAR: superimposes multiple reflected light beams to cause interference helping in construction of 3-d topographic maps. Time-series images of such topographic maps help in observing surface motion and change.
Capabilities
- 3-10 m spatial resolution
- Global coverage of land and ice cover every 12 days. (cryosphere)
- Can study of slow motion of earth’s crust with the help InSAR
- Study of biomass
Applications
- Earthquakes and vulcanology
- Distribution of carbon stocks in terrestrial biomass: Global warming applications
- Vulnerability of wetlands by studying the extent of inundation
- Geomorphology, movement of sea ice and hydrology
- Movement of glaciers and icesheets thereby climate change