Proximal sensing of land surface temperature

The land surface temperature (LST) governs the radiative energy budget of the Earth's surface and thus is one of the main input variables for land-surface models aimed at the estimation of soil moisture and evapotranspiration, monitoring of drought conditions and crop development, mitigation of urban heat islands, quantifying soil, vegetation, and whole ecosystem response to climate change, simulating hydrological processes, and forecasting of extreme climate events (i.e., drought, wildfires, and flooding). Because the LST affects a wide range of physical, chemical, and biological soil processes from the local to the global scales, and because of its significant spatiotemporal variations, advanced methods for measurement of the LST are of essence. Proximal sensing techniques based on thermal infrared imaging or passive microwaves are powerful means for LST determination. In this Chapter we present state-of-the-art proximal LST sensing techniques, discuss the underlying theories and algorithms, and provide examples for the application of LST information.