SMAP Radiometer versus Radio Frequency Interference

  • Released Tuesday, January 27, 2015

The microwave radiometer on NASA's Soil Moisture Active Passive (SMAP) satellite was designed and built at NASA's Goddard Space Flight Center. Along with the microwave radar, data from the radiometer will be used to calculate the water content of Earth's soil.

All types of soil emit microwave radiation, but the amount of water changes how much of this energy is emitted. The drier the soil, the more microwave energy; the wetter the soil, the less energy.

But radio frequency interference is a problem, even though the instrument is passively listening in a region of the microwave spectrum where transmission is prohibited. Some of the signals from the surrounding regions leak into the protected "listen-only" band. Goddard engineers developed new hardware and software to search for and cut out the erroneous measurements.

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Please give credit for this item to:
NASA's Goddard Space Flight Center

Release date

This page was originally published on Tuesday, January 27, 2015.
This page was last updated on Wednesday, May 3, 2023 at 1:50 PM EDT.


This visualization can be found in the following series:


This visualization originally appeared on the following tapes:
  • SMAP Radiometer (ID: 2015009)
    Wednesday, January 28, 2015 at 5:00AM
    Produced by - Walt Feimer (HTSI)