A New Approach to Space Communications During Re-entry Based on the Propagation Characteristics of Electromagnetic Waves in Ionized Media
- Paper ID
IAF-60-57
- author
- company
The Hallicrafters Co.
- country
U.S.A.
- year
1960
- abstract
This paper analyses the propagation characteristics of electromagnetic waves in ionized media with a view towards the elimination of the communication blackout which occurs when a missile re-enters the earth’s atmosphere. The results of the analysis reveal several major features in the transmission characteristics of the plasma which surrounds the missile. It is found that wave propagation is possible below plasma resonance when collisions between electrons and neutral molecules or atoms are present. This mode of propagation becomes practical when the collision frequency exceeds the plasma resonant frequency. The presence of windows in the electromagntic spectrum below the plasma resonant frequency is also investigated in great detail in this paper. Several windows are found to exist when longitudinal and transverse constant magnetic fields are applied. Of particular interest is the, existence of a window in the presence of a longitudinal magnetic field of intensity comparable to the earth’s magnetic field. The possibilities of long-range communication through this window are outlined. The feasibility of influencing the plasma transmission characteristics through the generation of large static magnetic fields is discussed.