一、引言 缓变源频谱的观测对于建立SVC的辐射理论及日地环境预报均有重要的理论价值和实际意义。为了提高射电望远镜的空间分辨率,天文学家利用日食的机会进行多波段观测,以取得缓变源的频谱。由于日食的机会不多,加上观测条件的限制,直到目前为止,从日食得到的缓变源频谱也不多。 I. INTRODUCTION The observation of slowly changing source spectrum has important theoretical and practical significance for establishing the radiation theory of SVC and the forecasting of the earth environment. In order to improve the spatial resolution of radio telescopes, astronomers use the opportunity of solar eclipses to make multi-band observations to obtain the spectrum of slowly changing sources. Due to the limited opportunities for eclipses and the limitations of observational conditions, so far, there have been only a few slow sources of change from solar eclipses.