Patent ID: 8433515

Claim:
A method for measuring a precision of a star sensor, comprising steps of: 1) fixing the star sensor on the Earth so as to point a main axis of the star sensor towards the zenith, the star sensor being inputable with time parameters which is stored with a navigation star catalog and visual movement parameters associated with a navigation star in the navigation star catalog; 2) inputting a current time (T) of a measuring start time relative to a J2000.0 time; 3) determining a directional vector of the navigation star in a J2000.0 Cartesian coordinate system at the current time (T) according to a right ascension and a declination (α, δ) of the navigation star in the J2000.0 Cartesian coordinate system and visual movement parameters (α′, δ′) of the navigation star in the direction of the right ascension and the declination which are stored in the star sensor; 4) converting the directional vector of the navigation star in the J2000.0 Cartesian coordinate system at the current time (T) into a directional vector of the navigation star in an ecliptic coordinate system; 5) converting the directional vector of the navigation star in the ecliptic coordinate system into a directional vector (v CRFT ) of the navigation star in a celestial coordinate system at the current time (T); and 6) converting the directional vector (v CRFT ) of the navigation star in the celestial coordinate system at the current time (T) into a directional vector (v TRF ) of the navigation star in a terrestrial coordinate system at an actual shooting time (T+Δt) according to the actual shooting time (T+Δt), and obtaining the precision of the star sensor based on the directional vector (v TRF ) of the navigation star in the terrestrial coordinate system.