Method for determining geomagnetic field components with reference to a satellite-fixed coordinate system

摘要

A method for determining the earth's magnetic field and, selectively, additionally, for determining a satellite orientation as a premise for the attitude control of an earth satellite in a known orbit. The satellite is equipped with magnetic coils 5, 6, and 7, gyros, sun sensors and reaction and/or flywheels 1, 2, 3, 4. The x-axis of a coordinate system integral with the satellite is continuously oriented towards the sun. The satellite can be rotated through a variable angle of rotation alpha around the x-axis. At three instants t0, t1, t2, spaced from each other by small time intervals, respective angular momentum components Hy, Hz are measured. Herein, a constant magnetic moment Mx is generated throughout the second time interval. From these domains, the components of the earth's magnetic field By, Bz are calculated for t0. From this, subsequently, the angle of rotation alpha can be determined. The components of the angular momentum result from the rpm's of the reaction and/or flywheels, as well as gyros.