Indian Remote Sensing satellites (IRS) are a series of Earth Observation satellites, mostly built, launched and maintained by Indian Space Research Organisation of India as part of the Indian space program. The IRS series provides remote sensing services to the country.
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The IRS system
Following the successful demonstration flights of Bhaskara 1 and Bhaskara 2 satellites launched in 1979 and 1981, respectively, India began to develop indigenous IRS (Indian Remote Sensing Satellite) program to support the national economy in the areas of agriculture, water resources, forestry and ecology, geology, water sheds, marine fisheries and coastal management. Later India established the National Natural Resources Management System (NNRMS) for which the Department of Space (DOS) is the nodal agency, providing operational remote sensing data services.[1] Data from the IRS satellites is received and disseminated by several countries all over the world. With the advent of high resolution satellites new applications in the areas of urban sprawl, infrastructure planning and other large scale applications for mapping have been initiated. The Indian Remote Sensing Satellite system is the largest constellation of remote sensing satellite in operation today in the world.[2] With the launch of CARTOSAT-2 [3], the constellation now has six satellites in operation – IRS-1D, OCEANSAT-1, Technology Experiment Satellite (TES), RESOURCESAT-1, CARTOSAT-1 and the latest CARTOSAT-2. All these are placed in polar sun-synchronous orbit and provide data in a variety of spatial, spectral and temporal resolutions to enable several applications to be undertaken relevant to the national development.
IRS data applications
Data from Indian Remote Sensing satellites are used for various applications of resources survey and management under the National Natural Resources Management System (NNRMS). Following is the list of those applications:
- Preharvest crop area and production estimation of major crops.
- Drought monitoring and assessment based on vegetation condition.
- Flood risk zone mapping and flood damage assessment.
- Hydro-geomorphological maps for locating underground water resources for drilling well.
- Irrigation command area status monitoring
- Snow-melt run-off estimates for planning water use in down stream projects
- Land use and land cover mapping
- Urban planning
- Forest survey
- Wetland mapping
- Environmental impact analysis
- Mineral Prospecting
- Coastal studies
- Integrated Mission for Sustainable Development (initiated in 1992) for generating locale-specific prescriptions for integrated land and water resources development in 174 districts.
IRS launch log
The initial versions are composed of the 1 (A,B,C,D). The later versions are named based on their area of application including OceanSat, CartoSat, ResourceSat. Some of the satellites have alternate designations based on the launch number and vehicle (P series for PSLV).
| Serial No. | Satellite | Date of Launch | Launch Vehicle | Status |
| 1 | IRS 1A | 17 March 1988 | Vostok, USSR | Mission Completed |
| 2 | IRS 1B | 29 August 1991 | Vostok, USSR | Mission Completed |
| 3 | IRS P1 (also IE) | 20 September 1993 | PSLV-D1 | Crashed, due to launch failure of PSLV |
| 4 | IRS P2 | 15 October 1994 | PSLV-D2 | Mission Completed |
| 5 | IRS 1C | 28 December 1995 | Molniya, Russia | Mission Completed |
| 6 | IRS P3 | 21 March 1996 | PSLV-D3 | Mission Completed |
| 7 | IRS 1D | 29 September 1997 | PSLV-C1 | In service |
| 8 | IRS P4 (Oceansat-1) | 27 May 1999 | PSLV-C2 | In service |
| 9 | Technology Experiment Satellite (TES) | 22 October 2001 | PSLV-C3 | In service |
| 10 | IRS P6 (Resourcesat 1) | 17 October 2003 | PSLV-C5 | In service |
| 11 | IRS P5 (Cartosat 1) | 5 May 2005 | PSLV-C6 | In service |
| 12 | Cartosat 2 (IRS P7) | 10 January 2007 | PSLV-C7 | In service |
Future IRS launches
Following are the remote sensing satellites planned by ISRO to be launched next strengthening the fleet of IRS satellites and widening their applications:[2]
- RISAT (Radar Imaging Satellite): A microwave remote sensing mission with Synthetic Aperture Radar (SAR) operating in C-band and having a 6 x 2 meter planar active array antenna based on trans-receiver module architecture. SAR is an all weather-imaging sensor capable of taking images in cloudy and snow covered regions and also both during day and night. RISAT weighs 1,750 kg. It is slated to be launched in 2007-2008.
- Oceansat-2: It is envisaged to continue the service of OCEANSAT-1. It will carry an Ocean Colour Monitor (OCM) and a Ku-band pencil beam scatterometer. It is slated to be launched in 2007-2008.
- Resourcesat-2: It will have imaging sensors similar to RESOURCESAT-1. Payload electronics have been miniaturised to reduce the overall weight. RESOURCESAT-2 is planned for launch by PSLV in 2009-10.
- TWSAT (Third World Satellite): TWSAT is the first satellite in the micro satellite series envisaged to provide 100 kg class satellite platform for carrying payloads for earth imaging, space science, atmospheric and ocean studies. TWSAT will carry a multi-spectral camera providing images with about 36 m. spatial resolution and swath of 151 km. The data generated will be transmitted to user terminals. The user terminals will be PC based systems along with RF downlink and antenna systems. The software will be capable of providing data products to standard product level with radiometric and geometric corrections.
Satellite data acquisition and processing
The National Remote Sensing Agency (NRSA) at Hyderabad is the nodal agency for reception, archival, processing and dissemination of remote sensing data in the country. NRSA acquires and processes data from all Indian remote sensing satellites like CARTOSAT-1, CARTOSAT-2, RESOURCESAT-1, IRS-1D, OCEANSAT-1 and TES as well as foreign satellites like Terra, NOAA and ERS. As per the Remote Sensing Data Policy, NRSA is the national acquisition/distribution agency for all satellite data within India.
References
External links
- CartoSat 2 images
- Official ISRO website
- FAS article on IRS system
- Bharat-Rakshak article on IRS system
