Abstract
<jats:p>Abstract. Thermal infrared (TIR) satellite remote sensing is essential for monitoring land surface temperature (LST) and surface energy fluxes, supporting applications in hydrology, agriculture, climate, and urban climate. Existing TIR missions—such as LANDSAT, ASTER, ECOSTRESS, and Sentinel-3 SLSTR—offer complementary capabilities but remain constrained by trade-offs between spatial resolution, revisit frequency, and radiometric accuracy, limiting their ability to capture rapidly evolving surface processes at field to regional scales. The TRISHNA (Thermal Infrared Satellite for High-Resolution Natural Resource Assessment) mission, expected in 2027, addresses this gap by providing 60 m TIR imagery over a ~1000 km swath with sub-weekly revisit, enabling systematic monitoring of surface energy processes in natural and managed ecosystems. Its integrated design —including orbit configuration, spectral channels (VNIR, SWIR, TIR), viewing geometry, and calibration strategy— supports accurate retrievals of evapotranspiration, vegetation water stress, and surface temperature dynamics. Synergies with upcoming missions such as ESA’s Land Surface Temperature Mission (LSTM) and NASA’s EAGLE mission (Explorer for Artemis Geology Lunar and Earth) will enhance temporal coverage, cross-calibration, and long-term data continuity.</jats:p>