In the framework of Aditya Saxena’s PhD, and in collaboration with Hervé Herbin (ULille) and Mélanie Ghysels-Dubois (IN AIR), our newly developed laser heterodyne radiometer (LHR) from the DFG group was deployed in several field campaigns for instrument validation and characterization.
(1) Campaigns at the CNES balloon launch facility in Aire-sur-l’Adour (AsA) in 2024 and 2025:
Vertical H₂O concentration profiles were measured from the ground to altitudes exceeding 14 km using the LHR. The results were successfully validated against high-resolution balloon-borne in situ measurements obtained with a micro-hygrometer, the Pico-Light H₂O TDLAS sensor, and radiosondes. In addition, the LHR can provide measurements of the diurnal variations in the atmospheric water-vapor column-averaged concentration, revealing the evolution of atmospheric dynamics throughout the day at ~2-min temporal resolution.
(2) Atmospheric CO₂ column measurements:
Field measurements of atmospheric CO₂ column concentration showed good agreement with independent satellite observations, with a measurement uncertainty of 0.42 ppm. This performance is comparable to that of current satellite observations and meets the sub-0.5 ppm precision level long considered necessary for high-precision CO₂ remote sensing.
