Vertical and oblique ionospheric soundings over a very long multihop HF radio link from polar to midlatitudes: Results and relationships

Abstract

[1] A vertical incidence sounder (VIS) was installed at the Spanish Antarctic Base (62.7°S, 299.6°E) during the Antarctic summer survey [2004][2005]. In addition, an oblique sounding (OS) system for HF communications between Antarctica and Spain (12,700 km) has been operated during the Antarctic summers since December 2003. OS results are compared to Rec533 model and to VIS data obtained from stations located along the radio path, including VIS stations at the emitter and receiver sites. The results presented in this paper show the potential of this infrastructure for ionospheric monitoring and research purposes at and from polar regions. The results also show that relevant information (e.g., maximum received frequency) of very long range radio links can be obtained from appropriate VIS stations along the path.

Remote Geophysical Observatory in Antarctica with HF Data Transmission: A Review

“…This HF radio link was used as multi-hop Oblique Ionospheric Sounder, OIS. In [57], Vilella et al have shown that the frequencies with largest availability of the HF radio link (FLA) correlate reasonably well with the MUF(3000)F2 recorded by VIS placed at the receiver site (40.8°N, 0.5°E) (see Figure 10, left) and that frequencies of OIS delivered at the receiver being larger than the MUF(3000)F2 recorded by VIS suffer a significant drop of power. The left plot of Figure 9 also shows the maximum usable frequency obtained by the Rec 533 model (MUF Rec 533) which is defined as the highest frequency for which an ionospheric communication path is predicted on 50% of the days of the month [58].…”

“…The significant decrease of the foF2 and their strong uplift of the F2 layer as observed by the significant increase in the virtual height, h'F2, for the geomagnetically disturbed period of 18 February 2005, was also investigated and explained in terms of a response of the ionosphere to the geomagnetic storms [55,56]. In addition, the data recorded with the AIS VIS, especially MUF(3000)F2, have been correlated with data extracted from the HF radio link established between the ASJI and Spain [57]. This HF radio link was used as multi-hop Oblique Ionospheric Sounder, OIS.…”

Fuzzy Logic Control for Multiresolutive Adaptive PN Acquisition Scheme in Time-Varying Multipath Ionospheric Channel

“…The behavior of the channel is well-known, as a result of several research studies (Vilella et al, 2009;, thus the control performance can be manually adjusted, by means of the acquisition system knowledge.…”

“…They are absolutely based on analysis of real data (Vilella et al, 2009;, except for scenario 0, that is a simpler version of transmissions throughout ionospheric radiolink, considering only the most powerful path in a multipath scenario. Table 1 is sorted by h l , that is the hour time -during day or night -.…”

“…The channel or simulation settings are defined according to the information given by (Vilella et al, 2009;, using measurements from real transmission campaigns. Lately, the four ratios curves for each scenario are obtained and explained for both acquisition and non-acquisition situations.…”