The Near Real Time (NRT) VIIRSLand Surface Temperature and Emissivity 6-Min L2 Swath 750m product (VNP21_NRT) uses a physics-based algorithm to dynamically retrieve both the LST and emissivity simultaneously for the three VIIRS thermal infrared bands M14 (8.55 micrometer), M15 (10.76 micrometer), and M16 (12 micrometer) at a spatial resolution of 750 m at nadir. The VNP21 algorithm is based on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Temperature Emissivity Separation (TES) algorithm. This algorithm uses full radiative transfer simulations for the atmospheric correction, and an emissivity model based on the variability in the surface radiance data to dynamically retrieve both LST and spectral emissivity at native pixel resolution. Additional details regarding the methodology are available in the Algorithm Theoretical Basis Document (ATBD) at:

https://viirsland.gsfc.nasa.gov/PDF/VNP21_LSTE_ATBD_v2.1.pdf

and user guide at:

https://viirsland.gsfc.nasa.gov/PDF/VNP21_LSTE_user_guide.pdf