Oceansat-2 : Another feat for Ahmedabad scientists

This is very good news for you if you have been complaining of unreliable weather forecasts. In a week of stellar achievements for Indian scientists, in which the discovery of water on the moon by Chandrayaan-I was confirmed by Nasa, another silent feat for the Space Application Centre, Ahmedabad, was the launch of Oceansat-2.

It is a remote sensing satellite designed by the city’s scientists for sharper monitoring of ocean and atmosphere. Oceansat-2 is India’s second satellite monitoring the oceans and atmosphere. It will provide key data on weather phenomena such as cyclones, assess fishery prospects, offer directions to sea vessels; and look for suspended sediments and effluents in rivers.

Visibly excited about the successful launch of the satellite, the director of SAC, Dr RR Navalgund, proudly told DNA that two of the three payloads aboard Oceansat-2 were developed at the centre. The payloads are: Ocean Colour Monitor (OCM) and Ku-band Scatterometer. The third, Radio Occultation Sounder for Atmospheric studies, belongs to an Italian agency.

“On Thursday, the camera of the OCM was switched on, and we can confirm it is working well,” Navalgund said. “Data will start streaming in soon, but it will be another six months before the information can be provided to agencies.” Oceansat-2 is an in-orbit replacement for Oceansat-1, which is a decade old.

“But its performance has not been affected,” Navalgund said. With the cost of the payloads pegged at Rs75 crore and that of the launch vehicle at Rs160 crore, the satellite is considered cost-effective. “Unlike Oceansat-1, the latest satellite will be able to gather data from all over the globe,” he said. “And this data will be available to everyone for a very nominal cost.”

Despite a mission life of at least five years, Oceansat-3, with improved capabilities, is being planned for 2011-12. Moreover, the SAC has commenced work on Chandrayaan-II, India’s first manned moon mission, and four remote sensing satellites. “A radar imaging satellite is slated for launch next year,” Navalgund said.


Oceans hold the key to climate change
Oceans, which cover almost 70% of the earth's surface, greatly influence its climate. Hence, oceans have a powerful impact on the world economy and daily life the world over.

Understanding the nature of the influence of oceans, particularly their role in shaping the earth's environment, has been a scientific priority. Improved observations of the physical and biological parameters of oceans have become important for any meaningful study of the earth's environment.

The conventional methods of studying oceans require the use of ships and buoys. These methods are not only difficult and expensive, very often they are not feasible at all. The situation began to change with the advent of satellites. Observations made by sensors aboard satellites going round the earth were regular and frequent enough to reduce the massive dimensions of oceans to manageable levels.

Ocean-watching satellites have thus become the best tools for studying these massive water bodies and measuring them over large areas on a regular basis. To understand the behaviour of oceans, it is essential to study their surface temperature, surface winds, humidity, precipitation, sea water salinity and other variables, at regular intervals.

Oceansat-2 will gather the needed data during its five-year mission life using the following three payloads - the Ocean Colour Monitor (OCM), the Ku-band Scatterometer (both made at SAC, Ahmedabad), and Radio Occultation Sounder for Atmospheric studies (ROSA).

In addition to these payloads, the Space Application Centre (SAC), Ahmedabad, is also responsible for data-product software development. "Scores of people on the Ahmedabad campus are involved in the project," said SAC director, Dr RR Navalgund, referring to the successful launch of Oceansat-2. "It is indeed very satisfying for all of us."