TRISHNA (Thermal infraRed Imaging Satellite for High-Resolution Natural resource Assessment) is a cross-purpose high spatial and temporal resolution thermal infrared Earth Observation (EO) mission that will provide observations in the domains of terrestrial and marine ecosystems, inland and coast, urban, cryosphere, solid Earth and atmosphere. It is an Indo-French innovative polar-orbiting mission that will overcome the limitations of TIR-optical observations from Landsat series and ASTER. The high-quality optical-thermal imagery will be used to provide precise surface temperature, emissivity and albedo of vegetation, manmade structures, snow, ice and sea. Atmospheric fields such as cloud mask and type, aerosol load, water vapour content will be well described. TRISHNA products will improve our knowledge of radiative and heat transfer to quantify evapotranspiration, fresh water discharge, snow-melt runoff, bio-geochemical cycle, urban heat island.