Interannual Variation of a 12,760 km Transequatorial Ionospheric Channel Availability and Its Dependence on Ionization

Abstract

Abstract:The ionosphere provides a channel able for long-haul and Non-Line-Of-Sight (NLOS) communications. Nonetheless, the amount of ionization depends on the Sun activity, whose diurnal and seasonal cycles transform the channel constantly. La Salle and the Observatori de l'Ebre have been sounding a 12,760 km ionospheric channel from Antarctica (62.7°S, 299.6°E) to Spain (41.0°N, 1.0°E) in order to find this evidence and to analyze the characteristics of this particular channel. The final goal of the project is to establish a stable communications link to be used as backup or for low rate data transmission. The aim of this paper is to prove the relation between the channel availability and the Sun phenomena affecting the ionization in four consecutive sounding campaigns.

Variation of Ionospheric Narrowband and Wideband Performance for a 12,760 km Transequatorial Link and Its Dependence on Solar and Ionospheric Activity

“…Most of the data received during the four campaigns show no available channel for communication [16], so there is a low number of measurements with data available to study. This resulted in a short number of files to study (see Table 1).…”

“…We also present the comparison between characteristics of narrowband and wideband soundings; Figure 8 depicts the frequency with largest availability (FLA) measured over the narrowband signal [16] with the matrices showing the results for the composite delay spread, the composite Doppler spread and the number of paths for Campaign 2013-14. The availability of the channel in wideband sounding has been evaluated with different considerations to those of the narrowband soundings, as explained in Section 3.…”

“…The relations between radio propagation and Sun phenomena have been widely studied in the past [15]. Narrowband sounding was already presented in [16], and tests of the dependence of its availability on solar activity were conducted in several studies. These studies have led us to conclude that narrowband propagation has a strong dependence on solar activity variations due to its influence on ionospheric performance in terms of electromagnetic propagation.…”