Development, evaluation and applications of the Cyclops-DP Weather Radar Processing system

Abstract

The move to increasingly high resolution numerical weather predictionmodels has created a demand for high resolution observations over wideareas, for model initialisation. The weather radar network is a valuablesource of such observations. To address this requirement and increasingconcerns of obsolescence in the UK Weather Radar network a program ofrenewal was undertaken. This resulted in the creation of the Cyclops-DP,dual polarisation weather radar processing and control system, which wasused as a platform from which investigation of novel radar observablescould be undertaken.The retrieval of near-surface refractivity changes, using fixed clutter targetsis investigated. It is shown that by combining dual polarisation measure-ments, an improvement in the correlation with surface observations isobtained. A novel method of determining the target location within therange gate, with the aim of reducing the bias and error in the refractivityretrievals, is tested but not shown to give benefit.The development of, what is thought to be, the first combined dual polar-ization weather radar and radiometer is described. It is shown that usefulradiometric measurements can be made using conventional radar hardwareand with relatively minor changes, the radar radiometric sensitivity is im-proved by a factor of 3.5. The sensitivity of the atmospheric backgroundnoise temperature to changes in temperature and pressure, as a function ofelevation, at C band is investigated for the purposes of radiometric calibra-tion. It is shown that a climatological profile can be used in calibrations withcertain caveats. A comparison of different methods of estimating the pathintegrated attenuation is presented and demonstrates that the radiometry-based estimates have skill and benefits compared to other techniques. Thepotential for using radiometric measurements to estimate partial beamblocking is demonstrated.

Date of Award	20 Mar 2015
Original language	English
Awarding Institution	University of Bath
Sponsors	The Met Office
Supervisor	Robert Watson (Supervisor)