Method scanning observation of a celestial body and for measuring an angular velocity of a spacecraft, observation system for its implementation, and the spacecraft comprising

Method scanning observation of a celestial body T from a space vehicle comprising a reference S by scanning observation system in a scan axis characterized in that there is formed two signals successively 16 a, B corresponding to the scanning in the same direction of movement of the same strip of soil BT is detected 17 in each of these signals a characteristic transition A1, B1 representative of the same characteristic point of this ground strip, is notes 18 the relative position of these transitions in the signals, and is determined 19 from a potential difference between the relative positions possible angular velocity omega of the spacecraft, given the time difference separating the instants at which each of these transitions has appeared in the said signals.