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 Meteorological Service (Deutscher Wetterdienst, DWD). Theoretically, dynamic frequency selection (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 under 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 radio frequency interference (RFI) sources as quickly as possible. The automated RFI detection algorithm for the German C-band weather radar network, operational since July 2017, makes use of routinely measured radar moments. Built upon data gathered since 2017, an RFI classification with respect to the severity and duration of RFI sources was first implemented in 2019. An independent verification of the RFI detection algorithm was performed by using a commercially available Wi-Fi 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 (Bundesnetzagentur, BNetzA). By following this workflow with great effort, the number of persistent RFI sources has been decreasing since October 2019, while a steady increase in short-lived RFI sources over the last 5 years also exists. In total, 11 889 RFI sources have been identified from July 2017 to May 2022. Most of these (94.8 %) are such short-lived sources 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 RFI sources negatively affect meteorological product generation.

中文翻译：

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DWD C 波段天气雷达网络中的射频干扰检测和缓解

C 波段气象雷达数据通常会受到来自外部源的干扰，即使气象雷达是该频段的主要用户，因此也是该频段的特权用户。德国气象局 (Deutscher Wetterdienst, DWD) 的雷达网络也是如此。从理论上讲，在 C 波段运行的设备的动态频率选择 (DFS) 应该可以防止对主要用户的任何干扰。实际上，这并不总是按照现行法规的预期运作。由于不可能从测量的天气雷达数据中分离出叠加的干扰信号，因此频带保护至关重要。目前，唯一可用的选择是丢弃雷达数据的受损部分。所以，目前最好的做法是尽快关闭射频干扰 (RFI) 源。自 2017 年 7 月开始运行的德国 C 波段气象雷达网络的自动 RFI 检测算法利用了常规测量的雷达矩。基于 2017 年以来收集的数据，2019 年首次实施了针对 RFI 源的严重性和持续时间的 RFI 分类。使用直接集成的商用 Wi-Fi 适配器对 RFI 检测算法进行了独立验证进入雷达接收器。随后，德国联邦网络局 (Bundesnetzagentur, BNetzA) 实施了缓解工作流，以有效识别和关闭检测到的 RFI 源。通过努力遵循此工作流程，自 2019 年 10 月以来，持久性 RFI 源的数量一直在减少，而在过去 5 年中，短期 RFI 源的数量也在稳步增加。从 2017 年 7 月到 2022 年 5 月，总共确定了 11 889 个 RFI 来源。其中大部分 (94.8%) 都是短暂的来源，因此 BNetzA 的明确识别通常是不可行的。然而，正如 C 波段法规所述，任何影响气象雷达运行的不合规发射机都必须关闭。这很重要，因为即使是这些短暂的 RFI 源也会对气象产品的生成产生负面影响。8 %）是如此短暂的来源，以至于 BNetzA 的明确识别通常是不可行的。然而，正如 C 波段法规所述，任何影响气象雷达运行的不合规发射机都必须关闭。这很重要，因为即使是这些短暂的 RFI 源也会对气象产品的生成产生负面影响。8 %）是如此短暂的来源，以至于 BNetzA 的明确识别通常是不可行的。然而，正如 C 波段法规所述，任何影响气象雷达运行的不合规发射机都必须关闭。这很重要，因为即使是这些短暂的 RFI 源也会对气象产品的生成产生负面影响。