Verfahren zur Wiederlangung der Lage eines dreiachs-stabilisierten Satelliten mittels Sternidentifizierung

• Main Author: FLAMENT, PATRICK, F-06110 LE CANNET, FR
• Format: Patent
• Language: German
• Published: 17.08.1995
• Edition: 6
• Subjects: AIRCRAFT; ANALOGOUS ARRANGEMENTS USING OTHER WAVES; AVIATION; CONTROLLING; COSMONAUTICS; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; GYROSCOPIC INSTRUMENTS; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; NAVIGATION; PERFORMING OPERATIONS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; REGULATING; SURVEYING; SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES; TESTING; TRANSPORTING; VEHICLES OR EQUIPMENT THEREFOR

For reacquisition of the attitude of a satellite wholly or partly three-axis stabilised, the method tests whether an Earth detector detects the Earth (test 1) and whether a star detector detects a star of magnitude at least approximately equal to that of a given reference star (test 2):   * case a : if tests 1 and 2 are positive, the Earth and the said star are captured, and the method tests the coherence over time of the roll information supplied by the Earth and star detectors : in the case of non-coherence it passes to case b;   * case b : if only test 1 is positive, the Earth is captured and the satellite is commanded in rotation in yaw until test 2 is satisfied; the said star is captured and the method proceeds to the coherence test provided for in case a;   * cases c and d : if test 1 is negative, the pitch speed is reversed during a given time at most; if test 1 becomes positive, test 2 is carried out: if test 2 remains negative, the method passes to case b, or else it passes to the coherence test; in default it passes to sun acquisition mode.