Coronal scattering of radio emission under strong regular refraction

Abstract

Abstract The influence of strong regular refraction (that leads to regular caustics and multipathing) in the solar corona on the structure of radio emission scattered by coronal turbulence is investigated. Distant cosmic sources and Sun's own radio sources are considered. It is shown that observations of the energy spectrum of spacecraft radio signals and of the mean profile of a pulsar pulse in the Sun's caustic shadow zone can be used for coronal turbulence diagnostics. It is also shown that strong regular refraction plays an important role in formation of solar millisecond spike bursts and of type IIId solar decameter radio bursts with echo components.