Solar corona effects on angle of arrival fluctuations for microwave telecommunication links during superior solar conjunction

摘要: [1] During the superior solar conjunction of spacecraft, transmitted signals from a spacecraft to Earth ground station graze region near Sun's photospheric surface, passing through dense and turbulent regions solar-charged particles. Phase changes due coronal irregularities cause raypath wandering, wavefront tilting, fluctuations in apparent angle arrival when observed Earth. This study presents first theoretical investigation wind effects on for RF signals. On basis Chandrasekhar relationship between phase angular fluctuations, an analytical integrating solution is derived by applying corona plasma irregularity spectrum models. It found that rapidly decrease with increasing heliocentric distance at rate ∼r−5.5 also frequency ∼1/f2. using Ka band α = 0.4° (r 1.6 radii), there 19 millidegrees (mdeg) scattering, corresponding 9 dB gain degradation. In comparison, lower-frequency X S undergo much worse degradation effects. Beyond 2° > 8 microwave bands can almost be neglected (θRMS < 1 mdeg). A minimize this use Ka- or higher-frequency telecommunication link during periods conjunction. not only quantifies caused but provides effective method diagnosing density very close surface.