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Quicklooks

Find here the quicklook browser of all the instruments in the FRM4RADAR network.

The quicklook browser is a helpful tool to

  • quickly check the current radar measurements and its quality
  • quickly browse through the whole data set
  • quickly check the smoothe functioning of the instrument

To do so the quicklook browser offers 3 different options of quicklooks. The 'radar overview', the 'radar status', and the 'weather station'.

  • The 'radar overview' shows the daily time-height-plot of the radar moments (Z, Vm, Sw, Ldr) and a time-series of the measured brightness temperature (Tb) from the passive 98-GHz channel. This option is used to quickly check the all measurements and identify possible issues in the measurements.
  • The 'radar status' shows the daily time-series of radar hardware control parameters (radar-PC temperature, the radar receiver- and transmitter-temperature, radar transmitter power, blower and heater status) and again the time-series of the measured brightness temperature (Tb) from the passive 98-GHz channel. Monitoring these parameters can help to identify radar performance issues or problems which might be already identified in the 'radar overview'-penal.
  • The 'weather station' shows the daily time-series of the Visata weather station attached to the w-band radar (rain rate, temperature, relative humidity and horizontal wind speed) and in the first panels the by the RPG software retrieved integrated Liquid Water Path (LWP) based on the measured Tb. This values are also useful to be able to check the instruments performance or to identify weather related issues.

The different radar sites and quicklook options can be selected in the drop-down menu at the bottom of the webpage. The number of panels displaying the measurements at one site can be adjusted there. 

Dataprocessing

Further Development of Existing Radar Processing

Within the FRM4Radrar project the existing radar processing of the University of Cologne (UoC) was developed further (Maahn and Kollias, 2012, AMT; Küchler et al., 2017, AMT; Küchler ,2019, PhD thesis at UoC).

The basic function of the Matlab code is the unfolding of measured Doppler velocities, so known as Doppler velocity dealiaising. The example in Figure 1 displays an hour of folded and unfolded Doppler velocities.  Before the correction in a) a jump in the in the Doppler velocity filed from negative to positive is visible between 1.2 km and 2.3 km. Folded Doppler velocities effect not only the velocity field also higher radar moments are affected (Doppler spectrum width, Skewness). Therefore, an unfolding of the Doppler velocity is necessary for a correct interpretation of the measurements. The code unfolds the Doppler velocity by shifting the measured Doppler spectra. The result of the unfolding is shown in Figure 1 b) where the jump in the velocities is gone and the velocity field shows conclusive values.

The updated processing is able to dealiaise measurements for profiling radars of RPG (RadiometerPysics GmbH). This includes the two raw data files of the instruments un- and compressed and unfolds Doppler spectra and co-spectra can calculated all relevant moments (Ze, vm, sk, ku, and Ldr). The data output is given in GEOMS conform NetCDF files. For mor documentation and to download the code visit github.