New paper about the design and validation of the Probes and Sensors for the Characterization of Magneto-Ionic Radio Wave Propagation on NVIS Paths
This article is the first journal paper of a joint project of the GTM from La Salle with University of Twente, University of Bath and the Communications Radioagency of The Netherlands. The article describes the design and validation of deployable low-power probes and sensors to investigate the influence of the ionosphere and the Earth’s magnetic field on radio wave propagation below the plasma frequency of the ionosphere, known as Near Vertical Incidence Skywave (NVIS) propagation. The propagation of waves that are bent downward by the ionosphere is dominated by a bi-refractive mechanism called ‘magneto-ionic propagation’. The polarization of both downward waves depends on the spatial angle between the Earth’s magnetic field and the direction of propagation of the radio wave. The probes and sensors described in this article are needed to simultaneously investigate signal fading and polarization dynamics on six radio wave propagation paths. Dr. Alsina-Pagès, member of the GTM, was leading the experiment site acquisition, deployment and validation in Catalonia. The collaboration plans to work further in the acquired data obtained in the experiment, because this is intended to use this novel instrument to contribute to future ionospheric propagation research. Interesting future extensions to the system could be time-of-flight measurements to investigate multipath and directional information to investigate origins of radio noise and of night-time scatter.
Statistical spectrogram showing the six probe signals as received by the sensor. The colour shows the relative occurrence in a 0.15 dB amplitude bin and a 3 Hz frequency bin.
Spectrogram of the LHCP end RHCP waves emitted by the probe and received by the sensor on a linearly polarized antenna, during normal NVIS propagation.
Witvliet, B.A.; Alsina-Pagès, R.M.; van Maanen, E.; Laanstra, G.J. Design and Validation of Probes and Sensors for the Characterization of Magneto-Ionic Radio Wave Propagation on Near Vertical Incidence Skywave Paths. Sensors 2019, 19, 2616. (link)