Two Measuring Methods for Antenna Rotating Center Based on Elevation Axes Intersection and Spherical Fitting

In traditional method, the model of elevation axis fitting is not rigor, which influences the accuracy and reliability of rotation center. To overcome this drawback, two new methods are proposed to get rotation center respectively based on elevation axes intersecting and spherical fitting. The trajectory of target points in different azimuths are fitted to acquire elevation axes which contain azimuth information, and the intersection of elevation axes is taken as rotation center, which is called as the elevation axes intersection method. This method is more reliable than the traditional method. The target points are fitted as a sphere to obtain a series of spherical centers, and their average is taken as the rotation center, which is named as the spherical fitting method. This method avoids the process of circle fitting and axes intersecting, which is more reasonable than the others. An uplink antenna array consists of three φ3 m antennas is taken as experimental object. Total station and industrial photogrammetric system are combined to get the coordinates of points on antenna. By employing the two new proposed methods, the antenna rotation centers are precisely acquired in a sub-millimeter level.