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Problems in measurements and the correction of them

The aim of this chapter is for the forecaster to be able to understand and avoid misinterpretations of non-meteorological targets and other reasons causing phenomena sometimes seen on radar, and also the conditions when you do not see precipitation even when it is there. Also understand the quantitative error sources.


This is a section which is mainly used as linked background information.


- 5.1 Ghosts (echoes not correlating with ground truth)

  • Birds, insects and other biological targets
  • Ships, planes, chaff and other man-made targets
  • Sea clutter
  • Ground clutter
  • Anomalous propagation
  • Second trip echoes
  • Flare echoes (three-body scattering)
  • Interference
  • Evaporation, overhanging precipitation, virga
  • Side lobe contamination
  • Sun


- 5.2 Angels (cases when precipitation exists and radar does not see it)

  • Total beam blocking
  • Total beam overshooting
  • Attenuation


- 5.3 Quantitative

  • Partial beam blocking
  • Attenuation
  • Folding (range and velocity)
  • Vertical profile of reflectivity, bright band, partial beam overshooting (specially in TOPS)
  • Orographic enhancement
  • Arcs and rings due to CAPPI interpolation


Material to this section is available through:

- Laurent Delobbe: animations, PowerPoint presentations and case study material
- Iwan Hollemann: PowerPoint presentations
- Roger Deslandes: animations, PowerPoint presentations, quizzes and case study material
- Wilfried Jacobs: animations, PowerPoint presentations, case study material and other
- Urs Germann: animations, PowerPoint presentations, quizzes and other
- Evelyn Murphy: PowerPoint presentations
- Uta Gjertsen: PowerPoint presentations
- Niels Einar Jensen: animations and PowerPoint presentations
- A.J. Illingworth: PowerPoint presentations and other
- Paul Joe: animations, PowerPoint presentations and case study material
- R.J. Keeler: PowerPoint presentations and other
- Martin Hagen: PowerPoint presentations and quizzes
- Peter Rodriguez: case study material and other
- Günther Haase: PowerPoint presentations
- Frederic Fabry: animations and other

mise jour Wednesday 4 May 2016