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Launched in January 2015, the National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) observatory was designed to provide frequent global mapping of high-resolution soil moisture and freeze-thaw state every two to three days using a radar and a radiometer operating at L-band frequencies. Despite a hardware mishap that rendered the radar inoperable shortly after launch,...
In this paper we summarize the effort to enhance the SMAP radiometer data. The applied technique is based on the Backus-Gilbert theory which is the classical estimation method in microwave radiometry. We show details of our implementation and summarize the assessment of the SMAP L1C_TB_E product.
Since the beginning of its routine science operation in March 2015, the NASA SMAP observatory has been returning interference-mitigated brightness temperature observations at L-band (1.41 GHz) frequency from space. The resulting data enable frequent global mapping of soil moisture with a retrieval uncertainty below 0.040 m3/m3 at a 36 km spatial scale. This paper describes the development and validation...
Over the last few years, researchers have determined that sea spray from breaking waves can have a large effect on the magnitude and distribution of the air-sea energy flux at hurricane-force wind speeds. Characterizing the fluxes requires estimates of the height-dependent droplet size distribution (DSD). Currently, the few available measurements have been acquired with spectrometer probes, which...
This paper discusses an effort to create a fast, yet accurate GNSS-R simulator capable of spacecraft-altitude studies. A number of new techniques will be presented which were developed to significantly increase the simulation speed. The end goal of this work is to assess measurement fundamentals such as ocean altimetry accuracy as a function of altitude and antenna size. The first application of this...
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