Global retrievals of surface, cloud and radiative properties from satellite imager sensors require accurate calibration of the imager channels onboard geostationary (GEO) and low-Earth-orbit (LEO) satellites. A simple timely technique has been developed to routinely intercalibrate and normalize the imager channels. It matches collocated data with similar view, solar and relative azimuth angles. As a reference calibration source, this technique uses self-calibrating sensors from the Tropical Rainfall Measuring Mission (TRMM) Visible Infrared Radiometers (VIRS), the ERS-2 Along Track Scanning Radiometer (ATSR-2) and the Terra Moderate Resolution Imaging Spectroradiometer (MODIS). GOES-8, a common satellite, is then calibrated using VIRS. This calibration is then transferred to other GEO or LEO satellites. This paper discusses the absolute accuracies of the visible and infrared calibration. A table of visible calibration coefficients will be provided for GOES-8 thru GOES-10, Geostationary Meteorological Satellite (GMS-5), Meteosat-7, and NOAA-14.