Radio frequency interference detection and mitigation in the DWD C-band weather radar network
Year: 2022
Type: article
Abstract: . C-Band weather radar data are commonly compromised by interference from external sources even though weather radars are the primary and therefore privileged user of this frequency band. This is also the case for the radar network of the German Weather Service (Deutscher Wetterdienst, DWD). Theoretically, dynamic frequency stepping (DFS) by devices operating in the C-Band should prevent any disturbance of the primary user. In practice, this does not always work as intended by the current regulations. As it is not possible to separate a superimposed interference signal from measured weather radar data, the protection of the frequency band is of utmost importance. Currently the only available option is to discard the compromised portions of the radar data. Therefore, the current best course of action is to shut down interference (RFI) sources as fast as possible. The automated RFI detection algorithm for the German C-Band weather radar network is operational since July 2017, which makes use of routinely measured radar moments. Built upon the data gathered since 2017, an RFI classification with respect to the severity and duration of RFIs was first implemented in 2019. An independent verification of the RFI detection algorithm was performed by using a commercially available WIFI adapter, which is directly integrated into the radar receiver. Subsequently, a mitigation workflow was implemented to efficiently identify and shut down detected RFI sources by the German Federal Network Agency (BNetzA). By following this workflow with great effort, the number of persistent RFIs is decreasing since October 2019 while a steady increase in short lived RFIs over the last 5 years exists. In total, 11889 RFIs have been identified since July 2017 until May 2022. The majority of these (94.8 %) are so short lived that an unambiguous identification by the BNetzA is, in general, not feasible. However, as stated by the C-Band regulations, any non-compliant transmitter compromising the operation of a weather radar has to be shut down. This is important, as even these short lived RFIs negatively affect the meteorological product generation.
Authors: Maximilian Schaper, Michael Frech, David Michaelis, Cornelius Hald, Benjamin Rohrdantz
Institution: Deutscher Wetterdienst
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,585
OpenAlex ID: W4309287764