Research Of Aircraft Attitude Estimation Based On The DOA Information Of Collaborative Sources

This paper studies aircraft attitude estimation based on the DOA information of collaborative source. The aircraft attitude in the earth coordinate system is measured from the electromagnetic waves received by the electromagnetic vector sensor or the three orthogonal dipole electric(magnetic) antennas at a single receiving point.The main work of the paper is as follows:(1) This paper makes full use of the orthogonal decoupling signal model to describe the 3-D construction of polarized electromagnetic wave. The maximum likelihood method and MUSIC algorithm are introduced into the parameters estimation of partially polarized wave. Attitude reference information calibrated by information base station is delivered by polarized electromagnetic waves. The simulation experiments of traditional MUSIC algorithm and maximum-likelihood algorithm verify that the advantages of attitude oriented vector model on the parameters’ performance to polarization-airspace oriented vector model?the orthogonal coupling.(2)The two-crossed DOA vector coordinate system provides attitude reference for aircraft, which makes the aircraft complete own attitude. This coordinate system determined by the DOA information has nothing to do with the aircraft attitude. The transformation matrix from the aircraft coordinate system to the earth coordinate system can be achieved with a two-crossed DOA vector coordinate system. Spherical angle variance will be selected as index parameters to measure the direction of arrival error when there are multiple satellite signal source. The attitude parameters are fine tuned to find the parameters whose DOA error weighting is the smallest, and then aircraft matrix including much DOA information can be acquired.(3)The method first determines the aircraft reference attitude coordinate system and earth coordinate system conversion relationship; The CRB(Cramer Rao bound) of the parameters estimation will determine whether the environmental electromagnetic wave signal can be used to measure aircraft Attitude/Heading; we can make a gross judgment of the stability of the environmental electromagnetic wave according to the three characteristic values of reference attitude correlation matrix and real time attitude correlation matrix having equal ratios. Finally according to the coordinate system conversion relationship, the platform attitude is percept.