Sea ice coverage is measured daily using  the Special Sensor Microwave/Imager (SSM/I).  This instrument measures microwave brightness temperatures at 19.35, 22.235, 37.0 and 85.5 GHz in seven channels.  The measured footprints vary from approximately 13 x 15 km to 43 x 69 km depending on the frequency.

This sensor has been mounted on the Defense Meteorological Satellite Program (DMSP) F8, F11 and F13 platforms.  These are sun-synchronous, polar-oribiting satellites positioned at a nominal altitude of 830 km. 

The original data are binned daily and monthly on a polar stereographic projection.  These data are produced by the National Snow and Ice Data Center (NSIDC) in collaboration with NASA Goddard Space Flight Center (GSFC).

Webpage by Jasmine S. Bartlett, Oregon State University.