Estimation of Rodrigues parameters from vector observations

A recursive minimum variance algorithm for attitude determination is presented. The attitude is expressed by the Rodrigues vector, where only three parameters are needed to describe orientation. The advantage of using the Rodrigues parameters is computational. Attitude calculations involve only relatively simple algebraic expressions, which is advantageous especially in real-time applications. The efficiency of the derived algorithm is demonstrated using Monte-Carlo computer simulation results and in an initial alignment aerospace application