Computational study of long-range high-frequency ionospheric ducting
Abstract
The propagation of high-frequency (HF) signals over long distances by way of ionospheric channels is studied by computing ray trajectories in numerically specified ionospheres without magnetic field. Horizontal ionization gradients are introduced to provide favorable conditions for the injection rays from the ground into elevated ionospheric ducts. Electron density height distributions with and without ionization valleys are considered. The ducting efficiency, expressed in terms of the product of frequency- and launch elevation-angle interval for trapped rays, is controlled by negative horizontal ionization gradients for successful injection of rays and by the shape of the electron density height profile and its change with distance. Long-range ionospheric ducting of HF rays does not require but is facilitated by the continued presence of an ionization valley in the plane of the ray trajectory.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- November 1976
- Bibcode:
- 1976STIN...7726378T
- Keywords:
-
- High Frequencies;
- Ionospheric Propagation;
- Radio Range;
- Radio Signals;
- Computation;
- Computerized Simulation;
- F Region;
- Ionization;
- Magnetic Fields;
- Communications and Radar