SSMIS

SSMIS stands for Special Sensor Microwave Imager/Sounder, a passive microwave radiometer and sounding instrument carried on the United States Defense Meteorological Satellite Program (DMSP) weather satellites. It is designed to provide continuous measurements of the Earth’s atmosphere, surface, and cryosphere to support weather forecasting, climate research, and environmental monitoring through imagery and derived geophysical variables.

Technical overview: The instrument combines microwave imaging channels with sounding capability across a broad frequency range. It uses a cross-track scanning mechanism to observe large surface swaths with each satellite pass, enabling retrieval of atmospheric temperature and humidity profiles, sea surface wind speeds, precipitation rates, oceanic wind/wave information, sea ice concentration, and land-surface temperature metrics. The diverse channel set allows both high-resolution imaging and atmospheric sounding functions, contributing to a wide range of meteorological and environmental applications.

Platform history: SSMIS evolved from the earlier SSM/I family and has flown on multiple DMSP platforms since the early 2000s. Later units incorporated calibration improvements and expanded channel sets. The instrument is operated under a U.S. military weather mission framework, with collaboration among U.S. Air Force and partner agencies, integrating its data into the DMSP mission suite and satellite meteorology workflows.

Impact and data access: SSMIS data support numerical weather prediction, climate monitoring, oceanography, hydrology, and cryosphere studies. Standard products include brightness temperatures and derived geophysical variables. Data are distributed through official portals and shared with meteorological centers and research institutions worldwide, facilitating operational forecasting and scientific analysis.