Cloud cover over India as seen by INSAT-3D
The prediction of weather in the tropical regions, like India, is a major challenge due to the complex and dynamic nature weather system. The day to day changes of weather elements such as rainfall, temperature, wind speed and humidity are the important meteorological parameters to be monitored on a continuous basis. The meteorological satellites provide a synoptic measurement of weather parameters at frequent intervals. The satellite images on cloud cover and various parameters such as winds, rainfall, sea surface temperature etc., have become an integral part of weather forecasting.
Oceansat-2, launched on September 23, 2009, carries Ocean Color Monitor (OCM), Ku-band Scatterometer and a Radio Occultation Sounder for Atmospheric studies (ROSA). The OCM has eight narrow spectral bands operating in visible and near infrared bands; and facilitates the study of ocean productivity, detection of algal blooms, sustainable fisheries management, etc. The satellite also provides data for forecasting of sea state, sea surface wind vector, coastal climate and weather.
Processed Scatterometer wind data of Oceansat-2 satellite is being disseminated through NRSC website within 150 minutes of acquisition at Svalbard ground station. Scatterometer data is operationally utilised by NASA-NOAA (USA), EUMETSAT (European Meteorological Agency) and European Centre for Medium range Weather Forecasting (ECMWF). Global Area Coverage products of Ocean Color Monitor of Oceansat-2 satellite at 1 km resolution is made available through NRSC website for the global users.
Megha-Tropiques satellite has become the first of the eight-satellite constellation for Global Precipitation Measurement (GPM) coordinated by NASA. Data from all the four scientific instruments on-board are received in India and France. The data from three payloads (SAPHIR, SCARAB & ROSA) of the Megha-tropiques satellite are opened to global users across the globe from January 15, 2013. Everyday data is being processed and uploaded to NRSC website in near real time.
The INSAT series of satellites carrying Very High Resolution Radiometer (VHRR) have been providing data for generating cloud motion vectors, cloud top temperature, water vapour content, etc., facilitating rainfall estimation, weather forecasting, genesis of cyclones and their track prediction. These satellites have also carried Data Relay Transponders (DRT) to facilitate reception and dissemination of meteorological data from in-situ instruments located across vast and inaccessible areas.
ISRO has also designed and developed ground based observation systems such as, Automatic Weather Station (AWS), Agro-meteorological (AGROMET) Tower and Doppler Weather Radar (DWR) as well as Vertical Atmospheric Observations System such as GPS Sonde and Boundary Layer LIDAR (BLL). These ground based system would augment the space based observations and validating the outcomes pertaining to various earth system processes.