Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the medium distances range — usually 0–650 km (0–400 miles).

Dec 11, 2024 · To use NVIS, in addition to choosing an appropriate frequency where the ionosphere is cooperative, we want to radiate our signal straight up (or close to it). One …

Wide-bandwidth NVIS antennas can have horizontal (azimuth) directivity variance that can be mitigated in a number of ways. The SWR of a wide-bandwidth NVIS antenna must be …

Near Vertical Incidence Skywave (NVIS) is a propagation mode which uses high angle radiation to send signals almost straight up to be reflected back to Earth for very effective short to medium …

Near Vertical Incidence Skywave (NVIS) is an ionospheric skip operating technique that directs the strongest signals from a station vertically, or upward, rather than toward the horizon.

Unlike traditional low-angle skywave signals, the signals from a NVIS antenna are returned from the ionosphere almost vertically, and thus NVIS can provide local or regional coverage as well …

Dec 1, 2025 · NVIS, or Near Vertical Incidence Skywave, is a high-frequency radio technique where you send signals almost straight up into the sky. The ionosphere bends these signals …

NVIS (acronym of N ear V ertical I ncidence, S kywave) is a special mode of propagation that allows for mid-range communication (less than 600 km), in the range between groundwave …

6 days ago · This presentation focuses on Near-Vertical Incidence Skywave (NVIS) antennas, which are crucial for short-range radio communications, particularly in military and emergency …

There is no fundamental difference between NVIS and conventional skywave propagation; the practical distinction arises from different desirable radiation patterns of the antennas (near …