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Neglected Radio Blackout Induced by the Nonionized Airflow Sheath Around a Supersonic Aircraft
Author(s) -
Gong S. H.,
Zhao H.,
Hou M. Y.,
Li R. X.
Publication year - 2018
Publication title -
radio science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.371
H-Index - 84
eISSN - 1944-799X
pISSN - 0048-6604
DOI - 10.1029/2017rs006501
Subject(s) - supersonic speed , blackout , reflection (computer programming) , choked flow , physics , optics , fresnel equations , aerospace engineering , mechanics , refractive index , computer science , engineering , power (physics) , electric power system , quantum mechanics , programming language
Abstract The characteristics of the flow field around a supersonic aircraft are discussed. It is analyzed that there are interfaces between two adjacent regions with jump change of refractive index in the supersonic flow. The physical mechanism of the Fresnel reflection of an electromagnetic wave at the interfaces mentioned above is analyzed according to the Fresnel reflection phenomenon in the Earth atmosphere. The conditions for the Fresnel reflection in the supersonic flow field are discussed, and the formulae for calculating the Fresnel reflection coefficient are given. According to the process of a radio wave propagating across the interfaces in the supersonic flow field, the other radio blackout phenomenon is proposed for the first time, which is induced by the nonionized atmospheric sheath around a supersonic aircraft, and may be well neglected or mistaken for the plasma‐sheath‐caused radio blackout. The conditions of the nonionized‐atmospheric‐sheath‐induced radio blackout are investigated. The calculation results show that the neglected radio blackout is confined to a rather specific case, a very small range of grazing angles. However, it is significant for identifying the mechanism of radio blackout.