Tropospheric effects on HF Propagation
Abstract
An evaluation is made of the effect of tropospheric refractive bending on the propagation of HF radio waves. The index of refraction in the troposphere is modeled in terms of the CRPL Reference Refractivity Atmosphere-1958, while the index of refraction in the ionosphere is defined in terms of the transverse-ordinary mode of propagation, the electron density being represented by a Chapman model. Ray tracings are performed based on the assumption that the propagation media are stratified into layers of constant refractive index. The ground scatter distance and the true and virtual reflection heights are calculated as a function of surface refractivity and various electron density profiles. The relationship between radar range and target-ground distance is also examined. The existence of long range propagation paths beyond 4500 km for specific tropospheric and ionospheric conditions is discussed.
- Publication:
-
In AGARD Spec. Topics in HF Propagation 14 p (SEE N80-19372 10-32
- Pub Date:
- November 1979
- Bibcode:
- 1979sthp.agarS....M
- Keywords:
-
- High Frequencies;
- Radio Waves;
- Refractivity;
- Tropospheric Scattering;
- Electron Density Profiles;
- Mathematical Models;
- Propagation Modes;
- Radar Range;
- Wave Propagation;
- Communications and Radar