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Includes bibliographical references
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Department of Electrical Engineering
2016
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| _version_ | 1867613953018822656 |
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| access_status_str | Open Access |
| author | Atilaw, Tsige Yared |
| author2 | Cilliers, Pierre |
| author_browse | Atilaw, Tsige Yared Cilliers, Pierre |
| author_facet | Cilliers, Pierre Atilaw, Tsige Yared |
| author_sort | Atilaw, Tsige Yared |
| collection | Thesis |
| description | Includes bibliographical references |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/16475 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:44:19.956Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Department of Electrical Engineering |
| publisherStr | Department of Electrical Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/16475 Characterization of the Multipath Environment of Ionospheric Scintillation Receivers Atilaw, Tsige Yared Cilliers, Pierre Martinez, Peter Space Studies Global Positioning Systems Includes bibliographical references Global Navigation Satellite Systems (GNSS) are used to provide information on position, time and velocity all over the world at any time of the day. Currently there are four operational GNSS and one of them is GPS (Global Positioning System) that is developed and maintained by U.S Department of Defence (DoD), which is widely used and accessible all over the world. The accuracy of the output or even the availability of the navigation system depends on current space weather conditions, which can cause random fluctuations of the phase and amplitude of the received signal, called scintillation. Interference of GNSS signals that are reflected and refracted from stationary objects on the ground, with signals that travel along a direct path via the ionosphere to the antenna, cause errors in the measured amplitude and phase. These errors are known as multipath errors and can lead to cycle slip and loss of lock on the satellite or degradation in the accuracy of position determination. High elevation cut off angles used for filtering GNSS signals, usually 15-30°, can reduce non-ionospheric interference due to multipath signals coming from the horizon. Since a fixed-elevation threshold does not take into consideration the surrounding physical environment of each GPS station, it can result in a significant loss of valuable data. Alternatively, if the fixed-elevation threshold is not high enough we run the risk of including multipath data in the analysis. In this project we characterized the multipath environment of the GPS Ionospheric Scintillation and TEC (Total Electron Content) Monitor (GISTM) receivers installed by SANSA (South African National Space Agency) at Gough Island (40:34oS and 9:88° W), Marion Island (46:87° S and 37:86° E), Hermanus (34:42° S and19:22° E) and SANAE IV (71:73° S and 2:2° W) by plotting azimuth-elevation maps of scintillation indices averaged over one year. The azimuth-elevation maps were used to identify objects that regularly scatter signals and cause high scintillation resulting from multipath effects. After identifying the multipath area from the azimuth-elevation map, an azimuth-dependent elevation threshold was developed using the MATLAB curve fitting tool. Using this method we are able to reduce the multi-path errors without losing important data. Using the azimuth-dependent elevation threshold typically gives 5 to 28% more useful data than using a 20° fixed-elevation threshold. 2016-01-21T11:05:26Z 2016-01-21T11:05:26Z 2015 Master Thesis Masters MPhil http://hdl.handle.net/11427/16475 eng application/pdf Department of Electrical Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Space Studies Global Positioning Systems Atilaw, Tsige Yared Characterization of the Multipath Environment of Ionospheric Scintillation Receivers |
| thesis_degree_str | Master's |
| title | Characterization of the Multipath Environment of Ionospheric Scintillation Receivers |
| title_full | Characterization of the Multipath Environment of Ionospheric Scintillation Receivers |
| title_fullStr | Characterization of the Multipath Environment of Ionospheric Scintillation Receivers |
| title_full_unstemmed | Characterization of the Multipath Environment of Ionospheric Scintillation Receivers |
| title_short | Characterization of the Multipath Environment of Ionospheric Scintillation Receivers |
| title_sort | characterization of the multipath environment of ionospheric scintillation receivers |
| topic | Space Studies Global Positioning Systems |
| url | http://hdl.handle.net/11427/16475 |
| work_keys_str_mv | AT atilawtsigeyared characterizationofthemultipathenvironmentofionosphericscintillationreceivers |