ABSORPTION OF IONOSPHERICALLY PROPAGATED HF RADIO WAVES UNDER CONDITIONS WHERE THE QUASI-TRANSVERSE (QT) APPROXIMATION IS VALID
Abstract
This report presents expressions for the absorption coefficients of a plane electromagnetic wave propagating through regions of a weakly ionized magneto-ionic medium where the quasi-transverse (QT) approximation is valid. The QT approximation is most likely to hold in the ionosphere on long east-west and short equatorial paths. A comparison of absorption on representative paths calculated by using absorption coefficients for the upper and lower sign shows that the upper sign, the ordinary wave, suffers less attenuation than the lower, the extraordinary wave, and should be used for communicating. The ordinary wave is launched on short equatorial paths by aligning both transmitting and receiving antennas parallel to the earth's magnetic field. When the wave frequency is near the gyrofrequency, both the ordinary and the extraordinary waves are greatly absorbed, because deviative absorption is occurring in a 'high-loss' region. When the wave frequency is much greater than the gyrofrequency, the expression for both signs with the QT approximation is very nearly the same as the expression for the simple no-field case.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1964
- Accession Number
- AD0480588
Entities
People
- George H. Hagn
Organizations
- SRI International