Abstract:

With regard to the inferior techniques and poor accuracy of phase center calibration of antenna array, by the power of precise engineering surveying technique, a new calibration method is proposed considering the actual antenna pointing. First of all, an industrial photogrammetric system is utilized to get the coordinates of points on antenna panels in different postures, and the actual pointing of mechanical axis is obtained by least square fitting. On this basis, the coordinates of antenna rotation center are obtained by seeking the intersection of mechanical axes with the matrix method. Finally, the mechanical axis in arbitrary postures is estimated based on inverse-angle weighting interpolation method, and the reliable phase center is obtained by moving a fixed length from the projective center alone the mechanical axis. An uplink antenna array consists of three φ3 m antennas is taken as experimental object, all photogrammetric coordinate systems are unified by the engineering control network, each antenna phase center is precisely calibrated with this proposed method. The effect of electrical signal synthesis shows that this method can effectively compensate the influence of gravity deformation and machining, and enhance the synthetic signal amplitude of uplink antenna array.

Key words: uplink array, phase center, rotation center, actual antenna pointing, three-dimension control network, precise calibration