Radar Research Group

of the Meteorological Institute in Bonn

Welcome to our radar homepage! The list below gives a rough overview on the research topics under investigation in our radar group. Click on a topic to get more information.

Backscatter differential phase δ

δ is a still underutilized polarimetric variable, which should not be ignored in rainfall retrievals based on specific differential phase KDP and bears valuable microphysical information.

GPM validation

For each overpass of GPM on the region detected by the Bonner radar, two and three dimensional data is created. This provides information about the current precipitation. To compare the GPM and BoXPol data, the polar data of the Bonn radar have to be interpolated on the GPM grid.


Lifecycle analysis of severe convective storms provide a deeper understanding of precipitation processes which can be exploited for nowcasting and model parameterizations.

Mixed-phase precipitation

It is extremely important to know the precise location of rain/snow boundary at the surface and its progression in time, and also to know if, where and when rain changes to freezing rain or ice pellets or other precipitation types.

Nowcasting Hailsizes

Object-based analyses of intense hail storms are performed and a hail size discrimination algorithm will be developed in order to distinguish between harmless and threatening hail sizes.

Radar compositing

The twin research X-band polarimetric Doppler radars in Bonn (BoXPol) and Jülich (JuXPol, in approx. 50km distance) and overlapping C-band radars of the German Weather Service are exploited to generate local 3D polarimetric composites. A 2D local BoXPol-JuXPol composite is generated operationally (Composite)


The fully equipped storm chaser bus for operation within the common Bonn/Cologne laboratory class and for research experiments includes a trailer equipped with a MicroRainRadar (MRR) and a ceilometer mounted on a steerable platform, a disdrometer, a fish-eye all-sky camera, and standard meteorological instruments (ventilated psychrometer, wind) installed on a telescopic rod, and a pressure sensor.


The twin X-band radar system of Bonn and Jülich is used to develop an empirical approach to quantify the uncertainties of radar based precipitation estimation. The use of two identical radars with a large overlapping area makes it possible to directly compare separate radar measurements in almost the same point in space and time.


Wradlib is an Open Source Library for Weather Radar Data Processing (wradlib). The radar group uses and also extends the library (Kai Mühlbauer, see below)

Convective Organization


Convective organizations can be observed on a range of scales from the smaller to the larger ones. The extend to which these organizations are important for climate remains, however, poorly understood. Particularly on the meso or sub-synoptic scales since global models used for climate studies do not include representation of subgrid-scale organization.

Ice characterization and quantification

To derive reliable relations between reflectivity Z and ice water content IWC is a challenging task, because they strongly depend on the snow habit. Thus, classification and quantification of ice above the freezing level is a new upcoming research topic within the research group.

Mammatus clouds

Multi-sensor observations of anvil mammatus are analyzed in order to gain a more detailed understanding of their spatio-temporal structure and microphysical characterization.

Model evaluation

Polarimetric radar measurements enable us to evaluate the representation of cloud and precipitation systems in the respective model and create an observational basis for model improvement.


Rainfall retrievals based on specific attenuation R(A) are less sensitive to variations in drop-size distribution, and unaffected by reflectivity biases due to miscalibration, partial beam blockage, and wet radomes.

Radar processing

The raw moment data is transferred in near-real-time to dedicated processing machines, which perform e.g. preprocessing, filtering, compositing, quantitative precipitation estimation QPE, and visualization on the institute's web-page (Archives).

Synergies with Microwave links

The variability in raindrop size distributions and attenuation effects are the two major sources of uncertainty in radar-based quantitative precipitation estimation (QPE) even when dual-polarization radars are used. New methods are introduced to exploit the measurements by commercial microwave radio links to reduce the uncertainties in both attenuation correction and rainfall estimation.

Wind Turbines

Windkrafträder in einem Rapsfeld, Offshorepark zur Energieerzeug

Algorithms in use to detect and eliminate backscatter differential phase δ are currently investigated to eliminate inhomogeneities in radar data generated by windmills.

Radar Group Members

Josephin Beer

current work: Masterthesis „Comparison of microwave backhaul links with the Bonn X-band radar“
other projects: Supervisor at the meterological lab course


Gordon Diefenthal, Ph.D. student

research interest: Uncertainties in radar measurements
other projects: TR32


Raquel Evaristo, Ph.D.

research interest: Object-based analysis (lifecycle of convective storms), Hail storms, Influence of windmills on radar measurements
other projects: HDCP2

Christoph Friedmann

current work: Masterthesis „Comparision of COSMO-DE with EMVORADO“
other projects: supervisor at the meterological lab course

Dr. Pablo Saavedra Garfias

current work: GPM validation
other projects:

Brandon Hickman, Ph.D. student

current work: Masterthesis „Nowcasting winter precipitation“
other projects:

Kai Mühlbauer

current work: Radar Processing, Remote Sensing, wradlib,
other projects: TR32

Velibor Pejcic

current work: Comparisons between GPM data and ground-based radar observations

other projects: Masterthesis „Analysis of electrical self-potential measurements at the alpine permafrost site Schilthorn with regard to meteorological and hydrological influences. “

Ieda Pscheidt, PhD student

current work: Generating high resolution precipitation fields from raingauge and satellite data
other projects: HD(CP)²


Dr. Silke Trömel

current work: ZDR-columns, Backscatter differential phase, Mammatus
other projects: HDCP2, TR32, Modex

radar/radargroup.txt · Zuletzt geändert: 2017/12/08 14:50 von veli

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