The Scanning Multichannel Microwave Radiometer (SMMR) ronounced ''simmer''was a five-frequency

microwave radiometer A microwave radiometer (MWR) is a radiometer that measures energy emitted at one millimeter-to-metre wavelengths (frequencies of 0.3–300 GHz) known as microwaves. Microwave radiometers are very sensitive receivers designed to measure thermally ...

flown on the

Seasat Seasat was the first Earth-orbiting satellite designed for remote sensing of the Earth's oceans and had on board one of the first spaceborne synthetic-aperture radar (SAR). The mission was designed to demonstrate the feasibility of global sa ...

and Nimbus 7 satellites. Both were launched in 1978, with the Seasat mission lasting less than six months until failure of the primary

bus A bus (contracted from omnibus, with variants multibus, motorbus, autobus, etc.) is a road vehicle that carries significantly more passengers than an average car or van. It is most commonly used in public transport, but is also in use for cha ...

. The Nimbus 7 SMMR lasted from 25 October 1978 until 20 August 1987. It measured dual-polarized microwave radiances, at 6.63, 10.69, 18.0, 21.0, and 37.0 GHz, from the Earth's atmosphere and surface. Its primary legacy has been the creation of areal

sea-ice Sea ice arises as seawater freezes. Because ice is less dense than water, it floats on the ocean's surface (as does fresh water ice, which has an even lower density). Sea ice covers about 7% of the Earth's surface and about 12% of the world's oce ...

climatologies for the Arctic and Antarctic. The final few months of operation were considerably fortuitous as they allowed the calibration of the radiometers and their products with the first results from the SSMI.

References

Jezek, K.C., C. Merry, D. Cavalieri, S.Grace, J. Bedner, D. Wilson and D. Lampkin 1991: Comparison between SMMR and SSM/I passive microwave data collected over the Antarctic Ice Sheet. Byrd Polar Research Center, The Ohio State university, Columbus, OH., BPRC Technical Report Number 91-03, .

External links

* http://nsidc.org/data/nsidc-0071.html * https://web.archive.org/web/20060930044535/http://podaac.jpl.nasa.gov:2031/SENSOR_DOCS/smmr.html * http://ieeexplore.ieee.org/xpls/abs_all.jsp?isnumber=25768&arnumber=1145458&type=ref Satellite meteorology Radiometry Earth observation satellite sensors {{Tech-stub