From the humble start from Bhaskara I to EOS-1, the Indian Earth observation satellite technology has advanced significantly. Earlier, the technology required by the Indian satellite system was imported from foreign nations, however with time state of the art technology has been developed indigenously. In this short journey, there has been remarkable advancement of technology in the earth observation satellite in resolution, sensor technology, application areas, coverage etc.
Experimental stage - The beginning of the Indian earth observation satellite journey started with experimental satellites like Bhaskara I in 1979 followed by Rohini RS-D1, Bhaskara II and Rohini RS -D2. These had limited capabilities in terms of sensor and resolution.
IRS series - In 1988, Indian Space Research Organization launched the first indigenous operational remote sensing satellite in the IRS series, i.e IRS – 1A. After this came the many satellites in IRS series i.e. 1A, 1B, 1E, P2,1C, P3, 1D, P4 and P6, each with improved capabilities than the previous one. IRS- P6 (which was continued as Resourcesat), launched in 2003, employed advanced multi-spectral LISS IV, LISS III and AWiFS sensor. The latest in this series is Resourcesat 2-A, launched in 2016, with much improved technology.
Oceansat series – The IRS – P4 satellite, launched in 1991, specifically for ocean applications was first one in the Oceansat series. The second satellite in this series is Oceansat -2 launched in 2009 with Ocean Colour Monitor-2 (OCM-2), Scatterometer and Radio Occultation Sounder for Atmospheric (ROSA) sensors. SCASAT – 1 is the continuing mission for Oceansat series with wind scatterometer sensor. The third one in this series Oceansat -3 is expected to be launched in 2020.
Cartosat series –The first satellite, Cartosat - I was launched in 2005 with resolution of 2.5 meters. Then came Cartosat 2 in 2007, 2A in 2008 and 2B in 2010, 2C in 2016, 2D and 2E in 2017, 2F in 2018 and the latest one is Cartosat 3 in 2019. The imaging capability of each is better than the last one. The latest in the series, i.e. Cartosat – 3 can produce scene specific spot image with high resolution of 0.25 meters.
RISAT series – India entered into radar imaging through RISAT – 2 satellite in 2009. The second in the series, RISAT – 1, was delayed and launched 2012. The next in the series was RISAT – 2B and 2BR -1 in 2019 and the latest one in the series is EOS-1 launched in 2020.
INSAT series – INSAT series satellites are advanced meteorological satellites There are two satellite in this series i.e. INSAT – 3D launched in 2013 and INSAT – 3DR launched in 2016.
Other than these, there are few individual special earth observation satellites were launched for specific purposes.
Technology experiment satellite (TES) - Experimental high resolution Technology experiment satellite (TES) launched in 2001.
Megha torpiques- An indo-french satellite mission launched in 2011.
SARAL (Satellite with ARgos and ALtiKa)- Another Indo – France collaboration mission, launched in 2013
HysIS - Hyperspectral imaging satellite launched in 2018.
The Indian earth observation satellite journey is not finished here but has just started. The present observation satellite system with high resolution multi-spectral remote sensing data is delivering data which is not only an asset for the scientific community but also for development of the nation.
Reference -
ISRO website, Department of Space, Indian Space Research Organization, https://www.isro.gov.in/about-isro
Image source - Free-Photos from Pixabay
