The ionosphere, which extends from ~60 km to ~1000 km, significantly affects the propagation of high-frequency (HF) to ultrahigh-frequency (UHF) signals which pass through it. The effects are varied but include refraction, retardation and scintillation. Ground-ground HF communications systems, ground-space communications systems, single frequency GPS (global positioning system), HF over-the-horizon radars, satellite altimeters and space-based radars are examples of radio systems constrained by this medium. Topics of interest include ionospheric morphology; ray tracing; MUF, multipath and other HF issues; fading and Doppler effects; and modem requirements on SNR, Doppler and multipath.

Inspec keywords: Doppler effect; modems; HF radio propagation; ionospheric electromagnetic wave propagation; ray tracing

Other keywords: radio systems; maximum usable frequency; HF over-the-horizon radars; ionospheric morphology; modem; ionospheric propagation; Doppler effect; single frequency GPS; refraction; space-based radars; multipath propagation; retardation; SNR; scintillation; ray tracing; satellite altimeters; ground-space communications systems; fading effects; ground-ground HF communications systems

Subjects: Ionospheric electromagnetic wave propagation; Radiowave propagation