초록 ▼

An apparatus for determining attitude of a satellite by using a star sensor includes a ground terminal equipped with a data processing unit and star catalogue, a star sensor, an estimating the unit for estimating attitude of the satellite and a decision unit for deciding the attitude determination m

An apparatus for determining attitude of a satellite by using a star sensor includes a ground terminal equipped with a data processing unit and star catalogue, a star sensor, an estimating the unit for estimating attitude of the satellite and a decision unit for deciding the attitude determination mode I or II in dependence on attitude stability of the satellite. In the mode I, angles representative of the satellite attitude are estimated by the estimating unit on the basis of a star sub-catalogue prepared by utilizing a priori information. In the mode II, the attitude angles are estimated by the data processing unit through data transaction with the ground terminal without resorting to the use of the priori information.

대표청구항 ▼

A system for determining the attitude of satellite which communicates with a ground station, said satellite comprising: a star sensor for observing star positions within a view-field of the star sensor; first memory means for storing star sub-catalogue data of positions of stars in a certain partial

A system for determining the attitude of satellite which communicates with a ground station, said satellite comprising: a star sensor for observing star positions within a view-field of the star sensor; first memory means for storing star sub-catalogue data of positions of stars in a certain partial area of the whole sky including the view-field of the star sensor; first data processing means for calculating attitude parameters of the satellite by comparing the observation data of the star sensor with the star sub-catalogue data stored in the first memory means; means for choosing either one of first and second operation modes for determining the attitude of the satellite, comprising means for choosing the first operation mode when stability of the attitude of the satellite satisfies a predetermined condition, or otherwise for choosing the second operation mode when the stability does not satisfy said predetermined condition; and first communication means for transmitting the attitude parameters calculated by said first data processing means when said choosing means chooses the first operation mode, and for transmitting the data of observation of the stars by the star sensor when the choosing means chooses the second operation mode; said ground station comprising: second communication means for communicating with the satellite; second memory means for storing star catalogue data of positions of stars in the whole sky; and second data processing means responsive to receipt of the attitude parameters from the satellite for producing the star sub-catalogue data for the certain partial area of the whole sky including the view-field by calculating the view-field of the star sensor on the basis of the attitude parameters, said star sub-catalogue data being transmitted to the satellite through said second communication means, and responsive to receipt of the data of the star observation of the star sensor from the satellite for calculating the attitude parameters of the satellite by comparing the star observation data with the star catalogue data stored in the second memory means and for transmitting said calculated attitude parameters to the satellite through said second communication means.