Proširenje područja rada sustava nadopune satelitske navigacije lokalno prilagođenim modelom ionosfere

doctoral thesis

• Title (english): Extension of operating area of satellite navigation augmentation system using locally adapted ionospheric model
• Author: Josip Vuković
• Mentor: Tomislav Kos (mentor)
• Committee member: Tomislav Kos (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Communication and Space Technologies); Zagreb
• Defense date and country: 2017, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Radio Communications
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Globalni sustavi za satelitsku navigaciju GNSS (eng. Global Navigation Satellite System) temelj su mnogih tehničkih sustava današnjice. Izvor najveće pogreške u GNSS-u je ionosfera, u kojoj zbog refrakcije dolazi do smanjenja brzine širenja elektromagnetskih valova između satelita i prijamnika. Europskim sustavom nadopune EGNOS (eng. European Geostationary Navigation Overlay Service) nadzire se cjelovitost rada globalnog sustava za pozicioniranje GPS (eng. Global Positioning System) te se procjenjuje stanje ionosfere iznad Europe. Te podatke, osim korisnika iz područja zrakoplovstva, upotrebljavaju i korisnici otvorene usluge EGNOS-a. U ovom doktorskom radu karakterizirana je EGNOS-ova pogreška procjene ionosfere nad srednjim geografskim širinama na području Europe u vrijeme različitih stanja ionosfere, uzrokovanih geomagnetskom aktivnošću, Sunčevom aktivnošću, godišnjim dobima i dobima dana. Globalni model ionosfere NeQuick 2 prilagođen je referentnim podacima o ukupnom sadržaju elektrona u ionosferi na promatranom području. Karakterizirana je točnost takvog lokalno prilagođenog modela s povećanjem udaljenosti od mjesta lokalne prilagodbe te su određeni radijusi u kojima pogreška modela odgovara pogrešci EGNOS-a. Uspoređeno je više inačica lokalno prilagođenog modela ionosfere NeQuick 2 te je predložena metoda proširenja geografskog područja rada otvorene usluge sustava EGNOS lokalno prilagođenim modelom ionosfere. Vrednovanjem točnosti određivanja položaja dobivenog korištenjem razvijene metode potvrđena je njena djelotvornost.

Abstract (english)

The ionosphere causes the biggest error in global navigation satellite systems as the refraction prolongs the propagation time of an electromagnetic wave travelling from a satellite to a receiver. European Geostationary Navigation Overlay Service (EGNOS) monitors the Global Positioning System's (GPS) integrity and estimates the ionospheric conditions over Europe. Those data are primarily intended for use in aviation, but EGNOS Open Service users also benefit of such data. In this doctoral thesis the EGNOS middle latitude ionospheric correction error was characterized in different ionospheric conditions, caused by solar activity, geomagnetic activity, seasons and time of day. The global ionospheric model NeQuick 2 was adapted by referent total electron content data from the observed area. The accuracy of such locally adapted ionospheric model and its decrease with distance from the local adaptation point were evaluated. Radii in which the model performance was comparable to that of EGNOS were determined. Different versions of locally adapted NeQuick 2 model were compared and a method for extension of the EGNOS Open Service operating area with locally adapted ionospheric model was proposed. The validation of positioning accuracy achieved using the proposed method confirmed the efficiency of the method.

• Keywords: GNSS; ionosfera; EGNOS; NeQuick~2; modeliranje ionosfere; lokalna prilagodba; svemirsko vrijeme
• Keywords (english): GNSS; ionosphere; EGNOS; NeQuick~2; ionospheric modeling; local adaptation; space weather
• Language: croatian
• URN:NBN: urn:nbn:hr:168:657499
• Study programme: Title: Electrical Engineering and Computing; Study programme type: university; Study level: postgraduate; Academic / professional title: Doktor znanosti elektrotehnike i računarstva (Doktor znanosti elektrotehnike i računarstva)
• Type of resource: Text
• Extent: 116 str. ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2019-04-05 13:10:20