RFI Detection and Mitigation in an sUAS Based L Band Correlation Radiometer for Soil Moisture Measurements

The Lobe Differencing Correlating Radiometer (LDCR) developed at Center for Environmental Technology (CET) at CU, Boulder is a lightweight payload for small unmanned aerial systems (sUAS) enabling remote soil moisture measurement for precision agriculture applications. The second revision of the payload (LDCR Rev B) includes a digital correlation detector for which the data processing flow, instrument calibration, and test data analysis is presented. Cross frequency peak detection, time and frequency domain kurtosis, and complex coherence phase are used to detect radio frequency interference (RFI) in the high spectral resolution radiometric data. A quiescent state performance analysis using matched loads and antennas revealing RFI generated from the radiometer high speed data acquisition system, and the sUAS communication system is discussed.