CAMCATT: a multisensor experiment over Toulouse to validate TRISHNA urban products
Résumé
An extensive field experiment, CAMCATT-AI4GEO, was conducted for 15 days in June 2021 over Toulouse, to acquire an urban reference dataset combining airborne acquisitions and ground measurements. This presentation aims at introducing the campaign and describing the collected data, which will be used for the validation of tools developed to produce future TRISHNA products, such as algorithms used for atmospheric compensation and temperature emissivity retrieval, microclimatic models. The several workshops of this experiment will be detailed. Joint airborne multispectral thermal infrared and VISNIR-SWIR hyperspectral images were acquired along a 30 km transect centred over Toulouse. A second flight was devoted to calibrating these sensors with on-ground reference targets. During and between the flights, two cars acquired air temperature and relative humidity along a predefined itinerary across the city with sensors mounted on their roof. During the airborne acquisitions, land surface temperature measurements were performed in three locations in Toulouse for calibration purposes. They were completed outside the flight by spectral optical properties in the VISNIR-SWIR and thermal infrared domains over a large range of manmade and natural materials. A specific in lab session was dedicated to the intercalibration of the on-ground thermal sensors. Atmosphere composition data were monitored using radio soundings during the airborne acquisitions and completed with continuous measurements from on-ground stations. Finally, the last session was devoted to the validation of a thermo-radiative model. For this purpose, surface temperature sensors were installed at different locations of buildings walls supplemented by a thermal infrared images acquisition for one of the facades in order to continuously monitor its temperature during the 15 days of the experiment. The air temperature was also measured at different positions in the district (under trees, in flats, etc).
