A5052895450- Ionosphere and magnetosphere dynamics
- Earthquake Detection and Analysis
- GNSS positioning and interference
- Space exploration and regulation
- Solar and Space Plasma Dynamics
- Spacecraft Design and Technology
- Geophysics and Gravity Measurements
- Geomagnetism and Paleomagnetism Studies
- Atmospheric Ozone and Climate
- Satellite Communication Systems
- Inertial Sensor and Navigation
South African National Space Agency
2011-2023
Rhodes University
2011-2018
Abstract The first regional total electron content (TEC) model over the entire African region (known as AfriTEC model) using empirical observations is developed and presented. Artificial neural networks were used to train TEC obtained from Global Positioning System receivers, both on ground onboard Constellation Observing for Meteorology, Ionosphere, Climate satellites years 2000 2017. network training was implemented inputs that enabled learn diurnal variations, seasonal spatial variations...
This paper presents a review on the PECASUS service, which provides advisories enhanced space weather activity for civil aviation. The are tailored according to Standards and Recommended Practices of International Civil Aviation Organization (ICAO). Advisories disseminated in three impact areas: radiation levels at flight altitudes, GNSS-based navigation positioning, HF communication. review, is based experiences authors from two years running pilot ICAO services, describes empirical models...
Abstract This paper focuses on unique aspects of the ionospheric response at conjugate locations over Europe and South Africa during 7–8 September 2017 geomagnetic storm including role bottomside topside ionosphere plasmasphere in influencing electron density changes. Analysis total content (TEC) 7 shows that for a pair geomagnetically locations, positive effect was observed reaching about 65% when benchmarked monthly median TEC variability Northern Hemisphere, while Southern Hemisphere...
Abstract On the 28 October 2021, a total of thirteen solar flares occurred. Of these, there were two M‐ and one X‐class while rest fell within C‐class category. The first second M‐class peaked at 0740 UT 1028 UT, respectively, X1.0 class reached peak 1535 UT. While it is known that strong cause absorption frequencies in high frequency (HF) range, F2 layer was consistently present on 2021 as shown by critical (foF2). However, using South African ionosonde data over Hermanus (34.4°S, 19.2°E)...
Abstract The ionosphere suffers major perturbations during severe space weather events such as Coronal Mass Ejections (CMEs), solar flares, high-speed streams, and Corotating Interaction Regions (CIRs). can experience depletions or enhancements in Total Electron Content (TEC) conditions. South African National Space Agency (SANSA) near-real-time (NRT) TEC maps were used to show the ionospheric variability geomagnetic storm of 3–8 Nov 2021 over southern Africa mid-latitude region. ionosonde...
Abstract This paper describes a new neural network‐based approach to estimate ionospheric critical plasma frequencies ( f 0 F2) from Global Navigation Satellite Systems (GNSS)‐vertical total electron content (TEC) measurements. The motivation for this work is provide method that realistic and accurate using GNSS receivers (which are far more commonly available than ionosondes) acquire F2 data. Neural networks were employed train vertical TEC corresponding observations respectively obtained...
Abstract The validation of the Local Disturbance index (LDi) and its first time derivative Current (LCi) is performed in Southern Hemisphere. Two South African magnetic observatories, Hermanus Hartebeesthoek contributed data for this study, two power stations, Grassridge Matimba, provided geomagnetically induced current (GIC) data. This focused on major geomagnetic storms, Halloween Saint Patrick's Day events that occurred October 2003 March 2015, respectively. comparative evaluation LDi LCi...
Ionospheric behavior plays an important role in high‐frequency (HF) radio propagation, which subsequently provides opportunity for studying ionospheric variability and space weather effects. The continuous change conditions caused by strongly affects HF propagation. use of communication is still very relevant over the African continent, as seen requirements services provided Regional Warning Center Space Weather Africa, this has necessitated investigation into prediction capabilities...
Abstract The ionosphere suffers major perturbations during severe space weather events such as Coronal Mass Ejection (CME), solar flares, high-speed streams, and Corotating Interaction Regions (CIR). During conditions, the can experience depletions or enhancements in Total Electron Content (TEC). South African National Space Agency (SANSA) near-real-time (NRT) TEC maps were used to show ionospheric variability geomagnetic storm of 3 – 8 Nov 2021 over Southern Africa mid-latitude region....
<p>The paper is focused on differences/similarities in regular daily ionospheric variability and the response to CME- CIR/CHSS-related magnetic disturbances above magnetically conjugated stations located at Northern Southern Hemisphere. We analysed of critical frequency foF2 F2 layer peak height hmF2 obtained for European-African sector initial, main recovery phases storms different intensity, which occurred within last two solar cycles. also used exclusively GPS-based...