It will provide simultaneous data on humidity, rainfall, water vapour, temperature
The Megha-Tropiques satellite is designed to study clouds in the tropical regions of the world that play a major role in climate change, said Roddam Narasimha, Member, Space Commission, on Wednesday at Sriharikota.
The Polar Satellite Launch Vehicle (PSLV-C18) put four satellites in orbit on Wednesday, including the Megha-Tropiques, which is an Indo-French mission. The Megha-Tropiques is meant for studying the weather in the short-term and climate in the long-term in the tropical regions of the world.
Dr. Narasimha, who along with the former ISRO chairman K. Kasturirangan, conceived the idea of building a satellite for specifically studying the global tropical weather, said that half of the land area in the world was in the tropics. The tropical region was a place where the skill in predicting the convective systems, humidity, water vapour and precipitation was of importance. Predicting the monsoons was a major problem in India, he said. Tropics radiated surplus energy received from the sun and this excess energy was transferred from the tropics to higher latitudes.
“The Megha-Tropiques promises to give us very special data,” said Dr. Narasimha, who was former Director, National Aerospace Laboratories, Bangalore. “It will provide simultaneous data on humidity, rainfall, water vapour, temperature etc.. in the tropical regions in real time.” This was the second satellite to study the global tropical weather after a satellite built jointly by the U.S. and Japan in 1997. He described the MADRAS (Microwave Imager for Detection of Rain and Atmospheric Structures) payload on board the Megha-Tropiques as “a livewire” instrument.
ISRO Chairman K. Radhakrishnan said Megha-Tropiques had four scientific instruments. They were: the MADRAS developed jointly by the ISRO and the French national space agency, Centre National d'Etudes Spatiales (CNES), which would provide an estimation of rainfall, water vapour, ice and surface wind; the Sounder for probing Vertical Profiles of Humidity (SAPHIR) from the CNES; the Scanner for Radiation budget, also from the CNES; and the Radio Occultation Sensor for Vertical Profiling of Temperature and humidity, procured from Italy.
While the PSLV-C18 cost Rs.90 crore to build, the Megha-Tropiques was made possible with Rs.85 crore each from India and France. That is, the satellite totally cost Rs.170 crore.
Data will come to Bangalore
T.K. Alex, Director, ISRO Satellite Centre, Bangalore, which built the Megha-Tropiques, said the satellite's solar-panels had been deployed and its two antennae had opened up. “The spacecraft is doing well…We will stabilise the spacecraft by using star-trackers and gyroscopes so that it will always be looking at the earth,”' he said. The science data sent by the satellite would be received at the ground station at Byalalu, near Bangalore and at Kourou in French Guiana. ‘But all the data will come to Bangalore and they will be processed there,” Dr. Alex said.
The satellite would cover the entire globe in a day and information from it would reach the public within three hours. The 1,000-kg Megha-Tropiques would have a life-span of five years.
G. Raju, Project Director, Megha-Tropiques, said ISRO would start analysing the satellite's data in about two to three weeks. P. Kunhikrishnan was the Mission Director for the PSLV-C18 launch.
The 10-kg SRMSat, from the SRM University, near Chennai, would address the problem of global-warming and pollution in the atmosphere by monitoring the carbon-dioxide and water vapour there. The three-kg Jugnu, from the IIT, Kanpur, has a camera to keep a tab on the vegetation and status of water bodies. The 29-kg VesselSat, built by LuxSpace of Luxembourg, has an automatic identification system for locating ships at sea in the region covered by the satellite's footprints.