Improved TRIAD for star sensor

TRIAD is an attitude determination algorithm, which only uses two observed vectors to calculate the attitude of spacecrafts. It has disadvantage of asymmetry using the two observed vectors and not making full use of all the observed star vectors captured by the star sensor. This paper presented an Improved TRAID algorithm to solve the problems above. It integrates all observed vectors on the basis of linear estimation theory. Comparing the experiment results of Improved TRIAD algorithm with the Traditional TRIAD and QUEST algorithm, it shows that the Improved TRAID algorithm can get higher attitude accuracy than the other two algorithms.