The modeling and measurement of HF antenna skywave radiation patterns in irregular terrain

Radio communication via Near Vertical Incidence Skywave propagation: an overview

“…Also the influence of the ground underneath the antenna installation is not negligible and has to be included in the measurement. However, in-situ measurement of antenna pattern and relative gain can be used for antenna evaluation, using a small transmitter transported by helicopter [73], airplane [74], tethered balloon [5] or remote controlled octocopter drone [75]. Due to the fast and deep fading imposed by ionospheric propagation, comparison of antenna performance using real-live NVIS transmitters is only possible when specialized techniques are used, such as described in [31, pp.…”

Near vertical incidence skywave

“…Also the influence of the ground underneath the antenna installation is not negligible and has to be included in the measurement. However, in-situ measurement of antenna pattern and relative gain for antenna evaluation can be achieved using a small transmitter transported by helicopter [Breakall, 1994], airplane [Jenkins, 1995], tethered balloon [Austin, 1988] or remote controlled octocopter drone [Krause, 2013]. Comparison of antenna performance using real-live NVIS transmitters is impossible due to fast and deep fading imposed by ionospheric propagation, unless specialized techniques are used.…”