Reflection of Electromagnetic Waves from Subionospheric Ionized Layers Produced by Intense Electromagnetic Beams
Abstract
Ionospheric layers produced by intense electromagnetic beams are characterized by an electron density profile that is nearly exponential in the lower boundary and an electron collision frequency that is nearly uniform. These features allow such layers to be approximated by Epstein profiles, which affords analytical exact full-wave coefficients subject to only two restrictions: (1) the incident wave is horizontally polarized, and (2) the layer is stratified. Simple criteria for good reflectivity are derived from the reflection- coefficient formulas. For overdense plasma layers having frequencies substantially above the wave frequency, the reflection loss is approximately -5. 8 x 0.00000008 Lcos theta dB where is the electron collision frequency at the layer altitude, 1/L is the height-gradient of the electron density in the layer boundary, and is the angle of incidence. Because calculations neglect roughness, which could be caused by uneven illumination by the ionizing beam, the conditions for good reflection presented in this report should be regarded as necessary--but not sufficient. Keywords: Ionosphere, Electromagnetic, Electron collision, Plasma layer, Reflectivity, Wave frequency, Ionizing beam.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1989
- Accession Number
- ADA225655
Entities
People
- Chris R. Warber
- Edward C. Field Jr.