LINEAR INDEPENDENCE OF STEERING VECTORS OF AN ELECTROMAGNETIC VECTOR SENSOR

In this paper, we investigate linear independence of steering vectors of one electromagnetic vector sensor. We show that every three steerin g vectors with distinct directions of arrival (DOA's) are linearly ind ependent. We also show that four steering vectors with distinct DOA's are linearly independent if the ellipticity angles of the signals asso ciated with any two of the four steering vectors are distinct. Moreove r, every four steering vectors corresponding to circularly polarized s ignals with the same spin direction are linearly dependent. We then es tablish that five steering vectors are linearly independent if exactly two or three of them correspond to circularly polarized signals with the same spin direction. Finally, we demonstrate that given any five s teering vectors, then for any DOA there exists a steering vector that is linearly dependent on the five steering vectors.