The Nimbus-6 High-resolution Infrared Radiation Sounder (HIRS) experiment was designed to accommodate channels in both the 4.3- and 15-µm infrared regions for improved temperature sounding. These channels were complemented by the 0.5-cm wavelength channels of the Scanning Microwave Spectrometer (SCAMS) to retrieve temperature profiles in cloudy conditions.

HIRS used passively cooled detectors and was capable of complete cross-track scanning. SCAMS also scanned, but had lower spatial resolution. The HIRS experiment successfully demonstrated an improved sounding capability in the lower troposphere due to the inclusion of the 4.3-µm observations.