Performance analysis of the Argentinian Meteorological Radar Radio Frequency Interference filter

A novel Radio Frequency Interference (RFI) filter is on the features list of the processor upgrade for the Argentinian Meteorological Radar (RMA).

The Argentinian network of weather radars: Sistema Nacional de Radares Meteorológicos (SINARAME) is composed by 15 C-band weather radars, 12 of which are RMA units. Almost all the SINARAME radars suffer from RFI contamination because C-band radars operate in the same frequency band as Radio Local Area Network (RLAN) and Wireless Area Network (WLAN).

This research presents the work conducted as part of the validation process of the software update for the RMA processor, before the release and upgrade of the SINARAME network.

Weather-only signals (I/Q time series), were collected from an RFI-free RMA site in the north of Argentina and chosen as the reference dataset.

RFI-only signals were collected from some of the most heavily RFI-contaminated sites, using the RMA radars as a receive-only antenna.

The RFI-only signals were numerically combined, at the I/Q level, with the weather-only signals, thus generating a new set of real-world weather data contaminated with real RFI signals.

The overall impact of contamination on data quality and the suppression capabilities of the filter was tested by applying the RFI filter to the artificially contaminated dataset and comparing the results with the reference (RFI-free) dataset.

Finally, a collection of several hours of I/Q data recorded from different RMA sites were processed, to study the RFI filter performance under different weather conditions and levels of contamination.

The results show that after tuning the filter parameters to the scanning strategy RFI contamination is greatly reduced without eliminating hydrometeors echoes for all the study cases.