In spite of on-board calibration, it is important to perform independent tests of satellite calibration to ensure the data are of the highest quality for climate research. Therefore methods have been developed to compare observations between a well-calibrated instrument and other radiometers whose calibration is most suspect. In this way, we calibrate infrared radiometers aboard the three primary geostationary series of satellites: the Geostationary Operational Environmental Satellite (GOES) series operated by the U.S., the Geostationary Meteorological Satellite (GMS) series of the Japanese and the European Meteorological Satellite (EUMETSAT) Meteosat. The record of data from these satellites at NCDC covers 1983 to present and covers most of the globe. The reference instrument with a stable calibration is the High-resolution Infrared Radiation Sounder (HIRS) which has flown on all NOAA polar orbiting satellites since 1983. We have corrected the geostationary calibration by comparing coincident geostationary and HIRS observations and in doing so we have provided a stable observation of infrared observations worldwide for the period of record.