Nasa-Isro Synthetic Aperture Radar

With NISAR, ISRO and NASA look to put difficult history behind

NEW DELHI: In 1992, the US under President George Bush had slapped sanctions on Indian Space Research Organisation ( Isro ) and prevented Russia from sharing cryogenic engine technology with the Indian space agency so as to check India from making missiles.Two decades later, US space agency Nasa has joined hands with Isro to co-develop the world’s most expensive earth imaging satellite that will cost the two countries over $1.5 billion. The irony is GSLV, which is likely to place this(NISAR) satellite into orbit in 2021, is the same rocket for whose cryogenic engine the US put sanctions on India.Leaving the past behind, Isro and Nasa are busy building the 2,200kg NISAR satellite , which will provide a detailed view of the earth by using advanced radar imaging. It is being designed to observe and take measurements of some of the planet’s complex processes, including ecosystem disturbances, ice-sheet collapse and natural hazards.Nasa became interested in Isro when the Indian space agency in April 2012 launched the country’s first indigenous radar imaging satellite (Risat-1), some called it a spy satellite, which enabled imaging of the earth’s surface during day and night under all weather conditions.The negotiations went on for two years but the formal agreement for NISAR satellite happened when Prime Minister Narendra Modi signed a declaration with former US President Barack Obama during his visit to the US in 2014. The objective behind the collaboration was to use the satellite for the “benefit of humanity” as the mapping data from this satellite will be available for all.Currently, the Ahmedabad-based Space Application Centre (SAC) is flight testing the “mini version” of the radar satellite over the city skies. The “mini radar” developed by SAC has been fixed on a Beechcraft Super King B 200 — owned by Isro — for the flight-testing primarily to ‘understand weather and geographical conditions’.SAC director Tapan Misra said, “We are testing the radar by taking images from about 8km above the sea level. The same area will be further studied by scientists from the ground level to understand the radar’s accuracy level.”He added, “For ground level data analysis, we are roping in NGOs, academic institutes, government departments and people with scientific expertise. This process of aerial data analysis will continue in Gujarat for three months until the crop season ends. We plan to conduct the same aerial-cum-ground exercise for three years in 39 places of the country, including over the Himalayan glaciers, Ganga, Sundarbans, Rann of Kutch, Andhra, Kerala and Karnataka, to study the geological changes in forests, vegetation, rivers and glaciers.”“The data gathered from the mini radar will be helpful when we will launch the NISAR satellite, most probably in 2021. The work on the main satellite is simultaneously going on,” the SAC director said.“The three basic functions of the satellite will be mapping the land mass, Arctic and Antarctica regions; analysis of seismic activities of the earth crust that will help in predicting earthquakes and tsunamis and analysis of drastic movement in glaciers and the rate at which these glaciers melt. The satellite, once put into its sun-synchronous dawn to dusk orbit, will map the entire world in 12 days,” he added.