HYGEOS at the International Workshop on High-Resolution Thermal Earth Observation

HYGEOS participated in the International Workshop on High-Resolution Thermal Earth Observation (THERMAL-EO), held from 18^th to 20^th November in Toulouse, France. The event focused on the future high resolution thermal infrared missions such as the Indian-French high spatio-temporal Thermal infraRed Imaging Satellite for High-resolution Natural resource Assessment (TRISHNA) mission, the Land Surface Temperature Monitoring (LSTM) mission and the Surface Biology and Geology (SBG) mission. It gathered contributors to the design of the missions, to the elaboration of scientific products as well as potential users.

During the event, we presented our work conducted for CNES as part of the TRISHNA mission. We have optimized the surface temperature and emissivity retrieval algorithm DirecTES [Marcq et al. 2023]. For that, we have developed a new generalist spectral library from the Combined ASTER MODIS Emissivity over Land (CAMEL) database [Borbas et al., 2018] and we have modified the selection criteria of materials in the spectral library. New DirecTES version 2 was tested with simulated Top-Of-Atmosphere THRISHNA radiances. Optimized DirecTES V2 globally reduces bias and root mean square error, with respect to the original DirecTES V1. The performances are significantly improved on desertic surfaces while they are not degraded in vegetated regions. All results are summarized in a poster.

Bias on LST retrieved with DirecTES V1 and V2, on images of TOA radiances simulated with CAMEL and ERA5 monthly averaged databases at 0.05° spatial resolution for August 2017.

Additionally, we engaged in insightful discussions on the application of surface temperature and exogenous data to assess urban heat islands, exploring innovative approaches to address environmental challenges in urban settings.