Abstract: A method and an apparatus for processing the output signals of an optical rth-horizon sensor (1) operating in the infrared range of an orbiting, e.g. stationary earth satellite with respect to variously warm oppositely located earth rims (earth anomaly). With the earth-horizon sensor (1), an off-course signal is formed which is a measurement of the off-course angle of the line of sight of the earth-horizon sensor in relation to the satellite/earth central point connection line and is used for the attitude control of the earth satellite. This off-course signal is corrected in dependence on the earth anomaly.