India launches satellite for better weather forecast

Bangalore  :  India’s advanced satellite Insat-3D, which was launched early Friday onboard Ariane-5 rocket from Kourou in French Guiana off the Pacific coast, will improve weather and monsoon forecasting system.

“After a perfect lift-off at 01:24 a.m. from the European Arianespace spaceport at Kourou, the two-tonne advanced weather satellite was placed in the geosynchronous transfer orbit (GTO) 32 minutes later, about 36,000 km above from earth,” the Indian Space Research Organisation (ISRO) said in a statement here.

The sophisticated spacecraft is orbiting at perigee (closest to the earth) of 249.9 km and apogee (farthest from the earth) of 35,880 km in the orbit.

“The satellite’s solar panel was automatically deployed soon after it was separated from the rocket’s upper cryogenic stage and our master control facility at Hassan took over its control for further manoeuvres,” the ISRO statement said. Hassan is about 200 km from Bangalore.

Preliminary checks of the subsystems showed the health of the spacecraft was satisfactory.

“The MCT will perform the orbit-raising manoeuvres over the next few days using the satellite’s propulsion system to place it in the intended geostationary orbit,” the statement pointed out.

The satellite will improve weather forecasting system, including predictions about the monsoon.

“This is a big step and will certainly improve our forecasting system,” Shailesh Nayak, secretary, union ministry of earth sciences, told reporters in New Delhi.

“Insat will send us data on weather every half-an-hour and these will be put in our computing models for preparing weather forecast,” he said.

Nayak, however, denied commenting on the accuracy. “The accuracy part, we will only come to know after using it for 6-8 months.”

The satellite’s observational instruments will be switched on during the second week of August after it reaches the orbital slot at 82 degrees east to the equatorial plane for extensive tests by the MCF.

The four instruments onboard the spacecraft are Imager, Sounder, Data Relay Transponder and Satellite Aided Search & Rescue. The six channel imager can take weather pictures of the earth and has improved features compared to the instrument in (Kalpana-1) and Insat-3A, the two Indian geostationary satellites, which have been providing weather services over the past decade.

“The 19-channel sounder payload adds a new dimension to monitor weather through its atmospheric sounding system, and provides vertical profiles of temperature, humidity and integrated ozone,” the statement noted.

Data relay transponder receives meteorological, hydrological, oceanographic parameters sent by the automatic data collection platforms located at remote uninhabited places and relays them to a processing centre for generating accurate weather forecasts.

The search and rescue instrument picks up and relays alert signals originating from the distress beacons of maritime, aviation and land-based users and relays them to the mission control centre to facilitate speedy search and rescue operations.

The state-run space agency will process the satellite’s data and the derivation of meteorological parameters with the Indian meteorological department in New Delhi.

An indigenously designed and developed meteorological data processing system has been commissioned at IMD, with a mirror site at the space agency’s space applications centre at Bhopal in Madhya Pradesh and Ahmedabad in Gujarat.