The new real-time measurement capabilities of the profiling TARA radar

Abstract

In the past 10 years, the S-band FM-CW TARA (Transportable Atmospheric RAdar), placed at the Cabauw Experimental Site for Atmospheric Research (CESAR), provided in real-time vertical profiles of the Doppler moments. Classical spectral processing was carried out. The polarimetric and multi-beam measurement capabilities of the radar were not exploited in real-time. It was only possible to acquire raw data for case studies. Based on them, new algorithms were developed using spectral polarimetry and the multi-beam capability of TARA. They have been tested during the COPS (2007) and EUCAARI-IMPACT campaigns (2008). To measure in real-time the Doppler moments of three beams, the differential reflectivity, the linear depolarization ratio, the horizontal wind and the vertical mean Doppler velocity, it became necessary to upgrade TARA. This resulted in a new design of the radar control unit and a new processing based on spectral polarimetry. This major upgrade took place in 2011. TARA can now deliver multi-parameters profiles with high spatial and time resolution and raw data in real-time. They are stored with the NetCDF format. Detailed quick-looks of the observables are available in real-time at http://ftp.tudelft.nl/TUDelft/irctr-rse/tara/index.html. For the design of the radar control unit and processing, a flexible solution that can process the data in a high level programming language, was chosen. This was done to be able to easily implement future developments in radar signal processing and algorithms.