Some satellite programmes

NOAA AVHRR The AVHRR is a radiation-detection imager that can be used for remotely determining cloud cover and surface temperature. This scanning radiometer uses 6 detectors that collect different bands of radiation wavelengths.
The first AVHRR was a 4-channel radiometer, first carried on TIROS-N (launched October 1978). This was subsequently improved to a 5-channel instrument (AVHRR/2) that was initially carried on NOAA-7 (launched June 1981). The latest instrument version is AVHRR/3, with 6 channels, first carried on NOAA-15 launched in May 1998. More information found here: http://edc.usgs.gov/guides/avhrr.html