This technology was developed for the Soil Moisture Active Passive (SMAP) mission and for the IRAD-FY13 Technology for Radiometer RFI Noise Detection & Mitigation Based on HHT2. Spacecraft beyond the present state-of-the-art passive radiometry will make use of natural thermal emissions to remotely sense Earth phenomena of interest to science (soil moisture, for example) in the technologically challenging microwave L-band. In this 1.4-GHz band (used by SMAP), a terrestrial source thermal signal emission to space suffers less attenuation by the intervening atmosphere. Unfortunately, the relative insensitivity of the L-band region to atmospheric effects also makes it an extremely attractive spectral range for wireless communications and radars that are causing radio frequency interference (RFI) with the spaceflight science radiometer instruments’ terrestrial phenomenon signal of interest, even as this band is protected by radio-communication regulations. Detection and excision or mitigation of the RFI-contaminated measurements is a challenge to the state of the art.

This innovation comprises ten production software C++ codes (L1B SPS RFI system) developed for SMAP and IRAD-FY13 that will detect and mitigate the SMAP radiometer instrument RFI. This software will perform the detection and mitigation of some 15% of science RFI-contaminated data. This technology is also applicable to all future spaceflight missions carrying radiometers, as well as to aerial surveillance projects.

The ten software source code modules are integrated and compiled as one executable for SMAP Radiometer Antenna Temperature Brightness (Tb) Software Processing System or L1B SPS RFI.

This work was done by Semion Kizhner, Matthew Brandt, and Jeffrey Piepmeier of Goddard Space Flight Center. GSC-16911-1

NASA Tech Briefs Magazine

This article first appeared in the June, 2015 issue of NASA Tech Briefs Magazine.

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