Intersection Point Determination of Parabolic Antenna Reflectors Using Close-range Photogrammetry

Abstract

In the construction of complex antenna structures, a number of feature points are inevitably formed on the main reflector surface of the antenna structure by bolting, riveting, cabling, and welding. In this study, the intersection point determination method using close-range photogrammetry was investigated. 3D position coordinates of many feature points distributed on the inner surface of a parabolic reflector were extracted using close-range photogrammetry. The fitting lines were estimated for the feature points arranged in the radial direction of the parabolic reflector, which tend to intersect at the center point of the reflector. The intersection point between the estimated fitting lines was calculated. The numerical variation of the intersection points on the three axes, which are accumulated through regular time-series calculations, can be used to intuitively predict and analyze not only the deformation rates but also the deformation directions for the shape of the parabolic reflector.