excursions:epfl_research_stay

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excursions:epfl_research_stay [2026/08/19 19:38] ayushexcursions:epfl_research_stay [2026/09/16 05:24] (current) ayush
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 While the agreement between observations and the reconstructions is strikingly similar, the retrieval of particle properties from radar Doppler spectra is ill-posed and the retrieved properties might not be correct even though their forward simulations look promising. Therefore, the retrieval needs to be validated with e.g. in-situ measurements. Such observations are not available for the TRIPEx-pol campaign. We are currently looking into data collected during the BAECC campaign (Petäjä et al. 2016), which provides triple-frequency Doppler spectra alongside in-situ observations of ice particles close to the ground. Further, in a next step, the added value a third frequency provides for retrieving particle properties will be tested. Also, the best combinations of two frequencies (e.g. X-,W-band vs. Ka-,W-band vs. X-, Ka-Band) will be tested to provide a recommendation of dual-frequency setups if only two frequencies are feasible. In the far future, the possibility to move from a fixed description of the PSD (i.e. through assuming a gamma distribution) towards a binned PSD might be explored, to improve the retrieval in cases of multi-modal spectra.  While the agreement between observations and the reconstructions is strikingly similar, the retrieval of particle properties from radar Doppler spectra is ill-posed and the retrieved properties might not be correct even though their forward simulations look promising. Therefore, the retrieval needs to be validated with e.g. in-situ measurements. Such observations are not available for the TRIPEx-pol campaign. We are currently looking into data collected during the BAECC campaign (Petäjä et al. 2016), which provides triple-frequency Doppler spectra alongside in-situ observations of ice particles close to the ground. Further, in a next step, the added value a third frequency provides for retrieving particle properties will be tested. Also, the best combinations of two frequencies (e.g. X-,W-band vs. Ka-,W-band vs. X-, Ka-Band) will be tested to provide a recommendation of dual-frequency setups if only two frequencies are feasible. In the far future, the possibility to move from a fixed description of the PSD (i.e. through assuming a gamma distribution) towards a binned PSD might be explored, to improve the retrieval in cases of multi-modal spectra. 
  
-<wc figure +<met figure 
-    src="https://www2.meteo.uni-bonn.de/spp2115/lib/exe/fetch.php?media=excursions:research_stay__leonie__1.png"+    src="/spp2115/lib/exe/fetch.php?media=excursions:research_stay__leonie__1.png"
     width="900"     width="900"
-    modifiers="natural fit outline"+    variant="outline"
     title="Figure 1"     title="Figure 1"
-    caption="Example of Doppler spectrogram at Ka-Band. Left: the observed “True” spectrogram, right: the spectrogram reconstructed with the retrieved properties.+    caption="Example of Doppler spectrogram at Ka-Band. Left: the observed “True” spectrogram, right: the spectrogram reconstructed with the retrieved properties.">
-    caption-align="left" +
-    click-action="lightbox" +
-    load-animation="zoom-in" +
-    background="none">+
  
-<wc figure +<met figure 
-    src="https://www2.meteo.uni-bonn.de/spp2115/lib/exe/fetch.php?media=excursions:research_stay__leonie__2.png"+    src="/spp2115/lib/exe/fetch.php?media=excursions:research_stay__leonie__2.png"
     width="900"     width="900"
-    modifiers="natural fit outline"+    variant="outline"
     title="Figure 2"     title="Figure 2"
-    caption="Example of $Z_e$ at horizontal polarization from 20190122. The first panel show the observations (True), the second panel the reconstruction with the retrieved properties.+    caption="Example of $Z_e$ at horizontal polarization from 20190122. The first panel show the observations (True), the second panel the reconstruction with the retrieved properties.">
-    caption-align="left" +
-    click-action="lightbox" +
-    load-animation="zoom-in" +
-    background="none">+
          
 </WRAP> </WRAP>
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 </WRAP> </WRAP>
- 
  • excursions/epfl_research_stay.txt
  • Last modified: 2026/09/16 05:24
  • by ayush