From spying to farming: The many uses of Risat-1

The successful launch of Risat-I by the Indian Space Research Organisation this morning propelled India into an elite group of nations that had the technology to launch microwave radar satellites into space. Popular perception links radar satellites to military spying operations, but according to N Gopal Raj in The Hindu , defence work is just one of the many things Risat-1 can do.

The biggest advantage of having a radar satellite is the fact that it can “see” even through clouds and fog. The main reason for that, according to Raj is the fact that “Optical satellites rely on sunlight to illuminate the ground below, working much like an ordinary camera does. Radar satellites, on the other hand, must send out pulses of radio waves and then pick up signals that bounce back.

Once the monsoon sets in over India, cloud cover often severely limits the useful images that satellites with optical cameras can supply. But radar can see through cloud and rain. Nor does darkness hamper its operation.”

Militarily Risat-1 will play a vital role as it “opens up avenues for watching over another country’s military operations. Such satellites can pick out military vehicles, aircraft and ships.” It can detect naval movements and also aid in examining if a nuclear reactor was being used for plutonium production.

However it will also play a huge role in aiding the agricultural sector. Raj notes that a radar satellite “opens up the possibility of monitoring crops grown during the monsoon when extensive cloud cover often hinders optical satellites.” India currently uses images from Canada’s radar satellites, but the indigenous Risat -1 will greatly reduce costs and enable India to carry out more extensive studies for establishing ways to monitor other crops with greater accuracy.

Besides this, The Hindu Article also says that the satellite will help in studying the Himalayan glaciers including their area and movement.