Validation of University of New Brunswick Ionospheric Modeling Technique with ionosonde TEC estimation over South Africa

Moeketsi, D. M. and McKinnell, Lee-Anne and Combrinck, W.L. (2009) Validation of University of New Brunswick Ionospheric Modeling Technique with ionosonde TEC estimation over South Africa. Advances in Space Research, 44 (6). pp. 725-735. ISSN 0273-1177



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For more than a decade, ionospheric research over South Africa has been carried out using data from ionosondes geographically located at Madimbo (28.38°S, 30.88°E), Grahamstown (33.32°S, 26.50°E), and Louisvale (28.51°S, 21.24°E). The objective has been modelling the bottomside ionospheric characteristics using neural networks. The use of Global Navigation Satellite System (GNSS) data is described as a new technique to monitor the dynamics and variations of the ionosphere over South Africa, with possible future application in high frequency radio communication. For this task, the University of New Brunswick Ionospheric Modelling Technique (UNB-IMT) was applied to compute midday (10:00 UT) GNSS-derived total electron content (GTEC). GTEC values were computed using GNSS data for stations located near ionosondes for the years 2002 and 2005 near solar maximum and minimum, respectively. The GTEC was compared with the midday ionosonde-derived TEC (ITEC) measurements to validate the UNB-IMT results. It was found that the variation trends of GTEC and ITEC over all stations are in good agreement and show a pronounced seasonal variation for the period near solar maximum, with maximum values ( 80 TECU) around autumn and spring equinoxes, and minimum values ( 22 TECU) around winter and summer. Furthermore, the residual ΔTEC = GTEC − ITEC was computed. It was evident that ΔTEC, which is believed to correspond to plasmaspheric electron content, showed a pronounced seasonal variation with maximum values ( 20 TECU) around equinoxes and minimum ( 5 TECU) around winter near solar maximum. The equivalent ionospheric and total slab thicknesses were also computed and comprehensively discussed. The results verified the use of UNB-IMT as one of the tools for future ionospheric TEC research over South Africa.

Item Type:Article
Uncontrolled Keywords:GNSS; GTEC; UNB-IMT; Ionogram; ITEC; Solar cycle; Plasmaspheric electron content; Slab thickness
Subjects:Y Unknown > Subjects to be assigned
Divisions:Faculty > Faculty of Science > Physics & Electronics
ID Code:1459
Deposited By: Mrs Eileen Shepherd
Deposited On:01 Sep 2009
Last Modified:01 Aug 2012 10:09
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