Improved determination algorithm using two vector measurements

To improve the spacecraft attitude determination accuracy and the computational efficiency of attitude matrix, an improved TRIAD algorithm was proposed. In this algorithm, the two observation vectors was weighted utilizing the variance of the measurement system, the weighting coefficient was selected according to the angle between the two observation vectors, the attitude matrix was solved using TRIAD algorithm, and then the matrix was amended. It shows that the computation time of this algorithm is half of the optimized TRIAD algorithm. When the measurement error of two sensors is difference, the accuracy of this algorithm is better than the optimized TRIAD algorithm for any angle of the two vectors. When the two sensors have the same measurement error, the accuracy of this algorithm is better than the optimized TRIAD algorithm except the angle of the two vectors is 90.