THE MICROWAVE TEMPERATURE AND HUMIDITY PROFILER: DESCRIPTION AND PRELIMINARY RESULTS

This manuscript presents the Microwave Temperature and Humidity Profiler (MTHP), a dual-band spectroradiometer designed for measuring multi-incidence angle temperature and humidity atmospheric profiles from an aircraft platform. The MTHP bands are at 60 GHz for measuring the oxygen complex lines, therefore at this band MTHP has a hyperspectral radiometer able to probide 2048 channels over 8 GHz bandwith, and the 183 GHz for measureing water vapor, which only uses 4 channels since this absorption band spectral richness is simpler. The MTHP builds upon the Microwave Temperature Profiler (MTP) with the inclusion of the hyperspectral readiometer. The instrument's de- sign, components, and calibration methods are discussed in detail, with a focus on the three-point calibration scheme involving internal calibration loads and static air tempera- ture readings. Preliminary results from the Technological Innovation into Iodine and GV aircraft Environmental Research (TI3GER) campaign are presented, showcasing the in- strument's performance during flights across diverse geographical regions. The manu- script highlights successful temperature and humidity profile retrievals and compares the measured data with simulations using the Atmospheric Radiative Transfer Simulator (ARTS). Additionally, the manuscript draws attention to potential Radio Frequency Inter- ference (RFI) effects observed during a specific flight, underscoring the instrument's sen- sitivity to external interference. This is the first time ever of an airborne demonstration of a broadband and hyperspectral multi-incidence angle 60 GHz measurements. Following MTHP works could result on an improved spatial resolution a of the atmospherical tem- perature vertical profile, and hence help estimating the Planetary Boundary Layer (PBL) with better accuracy. The MTHP and its hyperspectral multi-incidence angle at 60 GHz has potential to be a valuable tool for investigating the PBL's role in atmospheric dynam- ics, offering insights into its impact on Earth's energy, water, and carbon cycles.