Abstract: Here we analyze the noise contribution to electron multiplying CCD based on high dynamic range requirements of star tracker, and derive the signal-to-noise ratio computation formula for star detection. We also propose a design method for electronmultiplication voltage and cooling temperature. The attitude measurement error is less than 30″ when angular rate is 10(°)/s, which verifies the correctness of the designed method.

Key words: star tracker, electron multiplying CCD, electron multiplication, CCD cooling