Low-noise detector with RFI mitigation capability for the Aquarius L-band scatterometer

The upcoming Aquarius sea-surface salinity mission has tight requirements on backscatter measurement accuracy and stability at L-band frequencies (1.26 GHz). These requirements have driven the development of new capabilities in the scatterometer's backend detector electronics, which are the focus of this paper. Topics include the development of flight-grade hardware aboard the scatterometer for radio frequency interference (RFI) detection and mitigation, and analog/digital electronics design techniques used to reduce system noise and achieve highly linear power detection over a wide dynamic range. We also summarize the approach taken to test the scatterometer's processing and control functions at the level of the integrated Aquarius flight instrument, and present some recent results from the integrated testing campaign.