Broadband observations of propagation anomaly of VHF waves transmitted from oversea broadcasting stations

Broadband spectra in VHF band are regularly observed in Chiba, Japan to investigate anomaly of propagation of broadcasting waves from distant Asian broadcasting stations. TV broadcasting waves from China, Philippines, Thailand, Malaysia, and so on can sometimes propagate and there are three types of propagations. Seasonal and daily variations of received broadcasting waves were investigated through two-year observations. We also performed a simulation with the ray tracing method. In results, these propagations are caused by refraction in the F2 layer, by scattering on plasma bubbles, and by reflection in the Es layer.