Indian experience in ground based experiments in support of satellite data applications

Indian space programme is primarily directed to operationalise the regional and global applications of understanding and monitoring land, ocean and aerological processes using space platforms. Data from indigenous satellite series such as IRS, INSAT and SROSS, as well as foreign satellites of the type NOAA, NIMBUS, LANDSAT, SPOT and ERS have been utilised along with concurrent ground based measurements for the implementation of this programme. Carefully selected ground based experiments in association with satellite borne observations have been blended to investigate a number of phenomena relating to forest cover and volume, crop yield and biomass estimation, rainfall characteristics, evapotranspiration, soil moisture, snow cover and snow melt run-off and sea-surface temperatures. Optical, infrared and microwave remote sensing data from different satellites have been used in these studies and efforts are being made continuously to bring these to operational levels with supportive information from ground based instruments. Investigations have also been pursued in the areas of total ozone content and ground reaching solar B-UV fluxes, atmospheric aerosol distribution and its impact particularly during major volcanic eruptions, methane emission from rice paddy fields enhancing the greenhouse potential and the electrodynamics of ionospheric plasma and generation of spread-F irregularities. For these studies, both satellite borne and ground based data have been effectively combined to bring out the details of the physical mechanisms governing these phenomena. A few specific examples of the integrated ground based and space borne observations in the above areas of applications are presented. Such efforts are expected to lead to better modelling of our ecoenvironmental system, monsoon dynamics, weather and climate variations