Application of Digital Industrial Photogrammetric Technology to Measure the Surface Accuracy of 13.7 m Millimeter-wave Radio Telescope Antenna

In this paper,the surface accuracy of 13.7 m millimeter-wave radio telescope antenna is measured by digital industrial photogrammetric technology.In order to overcome the inconvenience introduced by local conditions,the circular orbits are used to transport the camera and wireless transmission is used to take on-line photos.Measuring targets are made of retro-reflective material.All camera stations are orientated and the homologous image points are matched automatically by the coded targets.The 3D point coordinates are calculated by the bundle adjustment method.Using the methods of CAD surface conversion algorithm and best fitting to calculate the deviation value of the surface,the RMS of the 480 points gotten from CAD best fitting algorithm is adjusted to 0.083 mm.The feasibility and superiority of photogrammetric technology,which is used to measure the radio astronomy antenna's surface,is demonstrated.