Radio Frequency Interference (RFI) refers to the unintended reception of a signal
transmitted by an external source. RFI contaminates remote measurements by adding
spurious noise of unpredictable characteristics. This may cause gaps in the data
collected by the HF radars, hence it is essential to know the existing RFI at the
proposed radar sites.
RFI tests were conducted over long periods of time at Ghar Lapsi in Malta and Ta'
Cenc in Gozo, at the locations where the new radars will be installed. During this
analysis, the existing background signals at 9.33MHz and 13.5MHz were continuously
recorded over a number of days. The huge amount of information (about 1TB) was
processed to extract a time series of the frequency spectra. This will allow
experts to identify the cleanest band in which to make HF Radar measurements.