Improving radar observations of rainfall: The value of dual polarisation

David Dufton
ICAS, University of Leeds

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David Dufton is a PhD student researching improvements in rainfall observations using dual polarisation weather radar. He has previously worked in flood risk management.

What are the new findings?

Weather radar provide wide area observations of the atmosphere, allowing quantitative measurements of rainfall along with a qualitative overview. Dual polarisation radars utilise horizontally and vertically polarised radio waves to provide extra information to conventional radars. Our research has shown the benefit of using these observations to filter out non-meteorological radar echoes, and therefore improve rainfall estimates. Ongoing research is further improving the accuracy of our measurements by applying additional  corrections based on dual polarisation information.

Why are these findings important?

The UK Met Office is currently upgrading the national radar network to use dual polarisation. Providing accurate distributed rainfall measurements will improve flood forecasting and numerical weather prediction. The NCAS mobile radar also allows us to use these measurements to improve our understanding of fundamental processes which will further improve these forecasts.

How did we discover this?

Data from the new NCAS mobile 3cm wavelength (X-band) weather radar has been analysed during this research. The radar provides high resolution observations of the atmosphere using dual polarisation technology. The data used in this work was obtained during the Convective Precipitation (COPE) field campaign (Cornwall, 2013). For more information on the X-band radar see the here.

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Above: Dual polarisation radar allows for many common radar error sources (left) to be removed and/or corrected for (right). In this example so-called ground clutter, caused by the high terrain of Dartmoor, has been removed, while reductions in beam intensity caused by blockages near the radar have been corrected for.

Find out more:

  • see David Dufton's webpage
  • Email: This email address is being protected from spambots. You need JavaScript enabled to view it.
  • Take a look at the journal articles:
    Dufton and Collier (2015): Fuzzy logic filtering of radar reflectivity to remove non- meteorological echoes using dual polarisation radar moments.

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This research was funded by NERC.