用单个小口径射电天线获得高空间分辨率图象的方法和试观测结果——DFT在天文上的应用(Ⅱ)

A Method for Obtaining Radio Images with High-SpatialResolution by Using A Single Small Radio Telescope and theTest Results-The Application of DFT to Astronomy (Ⅱ)

本文利用DFT象复原方法讨论了用单个小口径射电望远镜获得高空间分辨率图象观测的细节。包括天线方向图的实测和拟合,一维射电太阳象滤波函数的确定,噪声对复原精度和空间分辨率的影响。最后给出了三次试观测的复原结果。其中1987年7月1日的结果与Fleurs站干涉仪的观测结果十分相似。从所得的结果的细节估计达到了7角分的分辨率。

The details by means of the DFT. image restoration method for obtaining the images with high spatial resolution with a single small radio telescope, are presented in this paper, including the measurement and fitting of the antenna pattern, the determination of the filtering function of a one-dimensional radio solar image and the effects of the noise on the restoration accuracy and spatial resolution of the image. The restored results of three tests are given, of which the result obtained on July 1 , 1987, is quite similar to that obtained with an interferometer at the Fleurs Station, Australia. A resolution of about 7 arc minutes is attained from the estimation of the restored details. Finally, a method for finding the equivalent antenna diameter and the width of the main lobe by means of the one-dimensional radio solar scanning image is given in the appendix.