Publication Date:
2023-12-05
Description:
An important aspect of rainfall estimation is to accurately capture extreme events. Commercial microwave links (CMLs) can complement weather radar and rain gauge data by estimating path‐averaged rainfall intensities near ground. Our aim with this paper was to investigate attenuation induced complete loss of signal (blackout) in the CML data. This effect can occur during heavy rain events and leads to missing extreme values. We analyzed 3 years of attenuation data from 4,000 CMLs in Germany and compared it to a weather radar derived attenuation climatology covering 20 years. We observed that the average CML experiences 8.5 times more blackouts than we would have expected from the radar derived climatology. Blackouts did occur more often for longer CMLs (e.g., 〉10 km) despite their increased dynamic range. Therefore, both the hydrometeorological community and network providers can consider our analysis to develop mitigation measures.
Description:
Plain Language Summary:
Commercial microwave links (CMLs) are used to transmit information between towers of cellphone networks. If there is rainfall along the transmission path, the signal level is attenuated. By comparing the transmitted and received signal levels, the average rainfall intensity along the path can be estimated. If the attenuation is too strong, no signal is received, no information can be transmitted and no rainfall estimate is available. This is unfavorable both for network stability and rainfall estimation. In this study, we investigated the frequency of such blackouts in Germany. How many blackouts per year are observed in a 3 year CML data set covering around 4,000 link paths and how many are expected from 20 years of weather radar data? We observed that the average CML experiences 8.5 times more blackouts than we would have expected from the radar derived climatology. Blackouts did occur more often for long CMLs, which was an unexpected finding. While only one percent of the annual rainfall amount is missed during blackouts, the probability that a blackout occurs was very high for high rain rates. Both, the hydrometeorological community and network providers can consider our analysis to develop mitigation measures.
Description:
Key Points:
Complete loss of commercial microwave link (CML) signals during heavy rain leads to missing rainfall extremes.
Magnitude of observed blackouts exceeds climatologically expected values.
Unexpectedly, longer CMLs experience more blackouts.
Description:
Deutsche Forschungsgemeinschaft
http://dx.doi.org/10.13039/501100001659
Description:
Helmholtz Association
http://dx.doi.org/10.13039/501100009318
Description:
Bundesministerium für Bildung und Forschung
http://dx.doi.org/10.13039/501100002347
Description:
Karlsruhe Institute of Technology
http://dx.doi.org/10.13039/100009133
Description:
https://doi.org/10.5281/zenodo.7245440
Description:
https://github.com/pycomlink/pycomlink/blob/12fc302539851b19f7656cf7e2438c0ddbaa48bf/notebooks/Blackout%20gap%20detection%20examples.ipynb
Description:
https://doi.org/10.5281/zenodo.6337557
Description:
https://doi.org/10.5676/DWD/RADKLIM_YW_V2017.002
Keywords:
ddc:551.6
;
commercial microwave links
;
rainfall
;
opportunistic sensing
;
weather radar
;
rainfall extremes
;
precipitation
Language:
English
Type:
doc-type:article
Permalink
