Analysis of Possibility of Disturbance From Celestial Bodies on Satellite-Carried Optical Sensors

The satellite-carried optical sensors with various objectives may be possibly disturbed by the entrance of celestial bodies, such as sun, moon and earth into the sensitive area of sensors. In this paper, two kinds of satellite-carried optical sensors are discussed. They are the star sensor with a sensitive axe fixed on the spacecraft, and the satellite-carried astronomical telescope with a sensitive axe fixed in the space. A sensitive sector area of the optical sensor in the ecliptic plane or in the moon＇s plane is defined as the projective of the sensitive cone of the sensor on these planes. The disturbance occurs when the satellite-sun or satellite-moon vector enters into the sensitive sector area of the star sensor. A disturbance cone of the earth is formed from the satellite-earth vector and the contour of the earch. The disturbance occurs when the disturbance cone intersects the sensitive cone of the telescope. Based on the geometric relationships the conditions of disturbance from celestial bodies on the satellite-carried optical sensors can be determined and some formulas are derived to determine the time of occurrence of disturbance