Abstract
Radio frequency interference (RFI) is a well-documented problem for passive remote sensing of the Earth at L-band even though the measurements are made in the protected band at 1.413 GHz. Consequently, filtering for RFI is an important early step in the processing of measurements made by the SMAP (Soil Moisture Active/Passive) radiometer. However, the filtered data still include regions with suspiciously high antenna temperatures. One possible cause of these “hot spots” is interference not fully detected during RFI filtering. This paper presents evidence supporting this hypothesis and describes an algorithm to identify these “hot spots” so that they can be removed from the measurements. The impact of removing these “hot spots” is generally small, but evidence is presented that the brightness temperature and soil moisture improve when the hot spots are removed.
Highlights
SMAP (Soil Moisture Active/Passive) is a satellite mission to provide global maps of soil moisture and the freeze/thaw state of the surface by measuring radiation from the Earth’s surface at L-band
SMAP operates in a band where no transmission is allowed [5], the measurements are affected by radio-frequency interference (RFI) [6,7,8]
FSrMomvathluisesc,obmuptatrhisaot nthiet wSMas vsahlouwesntthhaattwuesirnegmtohdeinfieewd bflyagthsewnoeuwldflmagoydiiefyldoerdraemgroevaetevrenruymfebwerSoMf svuaclcueesss,fubul St MthartettrhieevSaMls. values that were modified by the new flag yielded a greater number of successful SM retrievals
Summary
SMAP (Soil Moisture Active/Passive) is a satellite mission to provide global maps of soil moisture and the freeze/thaw state of the surface by measuring radiation from the Earth’s surface at L-band. The instrument consists of a conically scanning radiometer operating in the 1400–1427 MHz band reserved for passive use only [1,2]. SMAP operates in a band where no transmission is allowed [5], the measurements are affected by radio-frequency interference (RFI) [6,7,8]. For the purpose of RFI detection, SMAP data are divided into two data streams [3]. Footprints are reported every 16.8 ms (which includes the time for internal calibration).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
