The NOAA K, L, and M satellites include updates to most instruments. Modified meteorological instruments include the AVHRR, HIRS, and MSU.

The most significant change made was to the Microwave Sounding Unit (MSU), renamed the Advanced Microwave Sounding Unit (AMSU). AMSU has 20 channels compared to 4 on the MSU at up to six times the spatial resolution of the MSU.

The new suite of channels for the first time allows for simultaneous retrieval of atmospheric and surface parameters in the presence of clouds for operational weather forecasting. Measured parameters now include water vapor profiles, integrated liquid water, precipitation rates and totals, soil moisture, sea surface wind speed, and atmospheric temperature.