Improved measurements of the atmospheric thermodynamic state, including water vapor and clouds are necessary to improve our understanding of many atmospheric problems. Clouds and water vapor are major players in climate and their accurate measurements are very important for furthering the scientific understanding of weather and climate. Unmanned aerial systems - UAS- are a new platform that can make such observations more frequently, more accurately and more affordable, but a lightweight, low power, autonomous sensors are lagging in development.
Microwave radiometers are uniquely capable of measuring path-integrated liquid water and water vapor in clouds and providing ice/water phase partitioning by mass within a given volume. The need for such an instrument was identified as the number one priority by The Department of Energy Biological and Environmental Research Office’s Aerial Observational Needs Workshop in 2015.
Existing microwave radiometers are notoriously large and demanding of electrical power, and thus present a challenge to airborne observations. A lightweight (4.6 kg), low power consuming (less than 30 W), small (613 mm long and 100 mm diameter) airborne microwave radiometer for atmospheric observations is being developed under the DOE SBIR Phase II project.
Profiling Airborne Microwave Radiometer - PAMR - will provide measurements in two polarizations within three bands: 60-90, 150 and 183 GHz. It is a modular instrument for which other radiometer bands or additional sensors for the PAMR can be developed in the future. PAMR is a “plug and play” instrument, operating autonomously from an- aircraft requiring only power from the hosting platform.
A novel type of the microwave radiometer receiver is the heart of our technological improvement. It enables a radiometer operation on a small UAS without a thermal or pressure control while improving radiometer calibration and sensitivity. It also promises a more reliable operation in the rugged environment of UAS operations.
We intend to install the PAMR on the Arctic Shark UAS. The progress of our work on this Phase II SBIR project will be presented.
