YAW ATTITUDE DETERMINING METHOD FOR THREE-AXIAL STABLE SATELLITE

摘要

PURPOSE:To accurately find the time when the segment connecting the center of the earth and the position of the satellite and the direction of the sun cross each other at right angles and to accurately determine the yaw attitude by finding the time when the segment and sun direction cross each other at right angles by using a sun sensor and a decision device. CONSTITUTION:A reference angle calculating device 3 calculates a reference detection angle momentarily. A comparator 4 subtracts the output of the reference angle calculating device 3 from the detection angle of a 1st sun sensor 1 and inputs the difference to a switch 6. This input value is accurately equal to the yaw attitude angle when the segment connecting the center of the earth and satellite position and the sun direction cross each other at right angles. The time of the crossing is the time when the sign of the detection angle of the 2nd sun sensor 2 is inverted, i.e. the time when the decision device 5 outputs a signal, and the switch 6 is closed at this time, so that the output of the switch 6 becomes the yaw attitude angle.