The move to increasingly high resolution numerical weather prediction models has created a demand for high resolution observations over wide areas, for model initialisation. The weather radar network is a valuable source of such observations. To address this requirement and increasing concerns of obsolescence in the UK Weather Radar network a program of renewal was undertaken. This resulted in the creation of the Cyclops-DP, dual polarisation weather radar processing and control system, which was used as a platform from which investigation of novel radar observables could be undertaken. The retrieval of near-surface refractivity changes, using fixed clutter targets is investigated. It is shown that by combining dual polarisation measure- ments, an improvement in the correlation with surface observations is obtained. A novel method of determining the target location within the range gate, with the aim of reducing the bias and error in the refractivity retrievals, 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 useful radiometric measurements can be made using conventional radar hardware and with relatively minor changes, the radar radiometric sensitivity is im- proved by a factor of 3.5. The sensitivity of the atmospheric background noise temperature to changes in temperature and pressure, as a function of elevation, at C band is investigated for the purposes of radiometric calibra- tion. It is shown that a climatological profile can be used in calibrations with certain caveats. A comparison of different methods of estimating the path integrated attenuation is presented and demonstrates that the radiometry- based estimates have skill and benefits compared to other techniques. The potential for using radiometric measurements to estimate partial beam blocking is demonstrated.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:698951 |
| Date | January 2015 |
| Creators | Darlington, Timothy |
| Contributors | Watson, Robert |
| Publisher | University of Bath |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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