Microwave holography measurement and adjustment of 25-m radio telescope of Shanghai

In an attempt to measure and correct the surface profile of the Sheshan 25-m radio telescope, the author carried out a phase coherent holographic experiment at 12.26 GHz with a geostationary communication satellite SINO-1 in the far field. To improve the spatial resolution, the author took the drift of the communication satellite into consideration. For the backend, a digital cross correlator was used to measure the complex beam pattern of the antenna under test. According to the data collected in the experiments, the holography software Call give the energy distribution map, error map, and a suggested adjustment for every junction of the panels, after four iterations of measurement and adjustment in a week, the surface accuracy of the antenna is improved from 0.948 mm to better than 0.5 mm. The experiment shows that the microwave holography is much faster and more convenient than traditional method. (c) 2006 Wiley Periodicals, Inc