The ground-based microwave profiler (MP3014), designed by Radiometrics Corporation, is operational at CIAO since February 2004. It measures the sky brightness temperature (Tb) at 12 frequencies: 5 in the K-band, distributed from the centre onto the wing of the 22 GHz water vapour resonance absorption line, the rest are in the V-band, distributed on one shoulder of the 60 GHz oxygen spin-rotation band. The radiometer is equipped with an infrared thermometer (IRT), installed on the top of radiometer cabinet, able to measure zenith sky brightness temperature (Tb) within the spectral range of 9.6 to 11.5 µm, and with surface meteorological sensors, used as constraints in the retrieval algorithm.

The microwave profiler is also able to perform a 3D scanning of the atmosphere though the measurements showed in the following are referred to Tb values obtained viewing only the zenith direction. The microwave profiler is also equipped with a rain effect mitigation system able to minimize error resulting from the accumulation of liquid water and ice on the microwave radiometer radome.

The Tb inversion provides temperature, humidity and cloud liquid water profiles up to 10 km above the ground station. Additionally, the inversion provides also an estimation of the Integrated Precipitable Water Vapour (IPWV) and of the cloud Liquid Water Path (LWP). Temperature, humidity and liquid water retrievals are obtained using a neural network algorithm trained by forward modelling several years of historical operational radiosonde data with a radiative transfer model.

The MP3014 was involved in an intercomparison measurement campaigns, LAUNCH-2005 at the DWD MOL-RAO Observatory in Lindenberg as well as in several international campaigns like, EAQUATE in 2004, COPS in 2007, LUAMI in 2008. The system is also part of MWRnet.

 

Contact person: Fabio Madonna