The $13.5-million Megha Tropiques satellite system for monitoring tropical weather conditions and monsoons will miss the deadline of 2005. The system is being developed by the Indian Space Research Organisation (ISRO) and the National Institute of Advanced Studies (NIAS) with French collaboration. Sources said that Centre National d’ Etudes Spatiales (CNES), the French space agency, was dragging its feet on the project. The agency was to jointly produce and launch the system which would monitor the tropical weather conditions, including monsoons and cyclones.

According to officials, India, is paying the launch costs and also for some of the payload and instrumentation work. It will be the first dedicated satellite devoted to atmospheric and climate research in the tropics. Scientists working on global climate studies all over the world have expressed interest in the project.

ISRO and CNES are jointly discussing the payload configuration for the Proteus Satellite Buss. The satellite is planned to be launched using ISRO’s Polar Satellite Launch Vehicle (PSLV) from Sriharikota range and would carry multi-frequency microwave and optical sensors to provide information on convective and cloud physical processes, water vapour, rainfall characteristics over ocean and land surfaces, monsoon radiation budget etc.

Changes in energy and water budget of the land-ocean-atmosphere systems in the tropics influence the global climate to a great extent and Megha Tropiques could provide the answer. The information would supplement and complement the data received from other Indian and global geo-stationary and polar orbiting satellites, officials explained.

The satellite data will be utilised by well identified scientists and their groups in both the countries. Megha Tropiques is expected to carry a multi-frequency microwave scanning radiometer (MADRAS), a multi-channel microwave instrument (SAPHIR) providing humidity profile of the atmosphere and a multi-channel radiation instrument, ScaRaB, providing data on the earth’s radiation budget.

ISRO and CNES signed an agreement in May 2001 to carry out studies of the Megha Tropiques mission.

Most of the satellites that have been launched to observe the variations in temperature, cloudiness, rainfall, water vapour and other parameters that influence the weather and climate are in geostationary or sun-synchronouspolar orbits.

In the last two decades, there has been an increasing realisation of the role played by tropical convective systems in modulating the weather and climate in tropics and extra-tropics.