A combined earth-star sensor system (1) for three-axis attitude determination
of satellites in space comprises separate apertures with different directions of
observation and common image pickup devices (4) for the earth sensor and
the star sensor. A common optical arrangement (2) for earth observation
and start observation, and a deflection mirror (3) for derivation of the
laterally entering light from the earth, to the common optical arrangement (2)
may be provided. In one focal plane there is a focal plane sensor with an array
of image pickup devices (4) with the integration time being controllable.
An evaluation unit determines the orbit and the attitude of the space vehicle from
the attitude and movement of the stars and of the rim of the earth in the focal plane.
