Method for reducing radiance errors in earth sensors

摘要

A horizon sensor orbiting the earth views the earth's horizon in at least two points in the earth's summer and winter hemisphere and calculates pitch and roll information therefrom. The summer pitch and roll information is calculated at intervals long with respect to pitch and roll rates, but short with respect to weather variation. The pitch and roll information is then periodically corrected during a predetermined correction interval using the summer hemisphere pitch and roll information.