CHARACTERISTICS OF RADIO FREQUENCY INTERFERENCE IN THE PROTECTED PORTION OF L-BAND

NASA's SMAP radiometer was launched in 2015, and owing to its digital backend is providing geolocated raw power moments measured at frequencies between 1400-1424 MHz with 1.2 ms and 1.5 MHz time and frequency resolution. Utilizing SMAP measurements between August 25-31, 2018, temporal and spectral properties of the RFI contamination within the protected portion of L-band have been retrieved. It has been found that the average bandwidth and duration of individual RFI sources are less than 4.5 MHz and 4.8 ms, respectively in most regions with exceptions over Europe, Middle East, and Eastern Asia. On the other hand, multiple RFI sources occupying different parts of the spectrum may lead to available RFI-free spectrum less than 12 MHz. Finally, there were no significant correlations noted among amplitude, bandwidth, and duration of RFI sources.