Pogreška satelitskog određivanja položaja zbog ekstremnih ionosferskih poremećaja

doctoral thesis

• Title (english): Ionospheric component of satellite positioning error due to extreme space weather disturbances
• Author: Renato Filjar
• Mentor: Tomislav Kos (mentor)
• Committee member: Boris Kviz (član povjerenstva)
• Committee member: Tomislav Kos (član povjerenstva)
• Committee member: Ivan Markežić (član povjerenstva)
• Committee member: Borivoj Modlic (član povjerenstva)
• Committee member: Serđo Kos (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Communication and Space Technologies); Zagreb
• Defense date and country: 2007-03-02, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Electrical Engineering; Radio Communications
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

U radu se analizira utjecaj ekstremnih ionosferskih poremećaja prouzročenih promjenama svemirskog vremena na vrijednosti ionosferskog kašnjenja signala za satelitsko određivanje položaja. Definira se pojam svemirskog vremena i parametri koji opisuju njegovo stanje. Opisuje se tvorba ionosferskih slojeva uslijed djelovanja svemirskog vremena, te definiraju parametri stanja ionosfere. Prikazuju se ionosferski modeli, koji povezuju parametre stanja ionosfere s parametrima stanja svemirskog vremena, te standardni model GPS ionosferskog kašnjenja. Identificiraju se ograničenja postojećih modela, posebno obzirom na stanje i dinamiku svemirskog vremena. Na konkretnom primjeru ekstremnih poremećaja svemirskog vremena i ionosfere tijekom listopada i studenog 2003. godine, analizira se utjecaj svemirskog vremena i ionosfere na vrijednosti ionosferskog kašnjenja GPS signala na području Republike Hrvatske. Vrijednosti GPS ionosferskog kašnjenja određuju se iz eksperimentalnih podataka prikupljenih na referentnoj stanici Osijek, Hrvatska. Promatra se dinamika GPS ionosferskog kašnjenja, te njena korelacija s dinamikom promjena svemirskog vremena i ionosfere. Rezultati analize koriste se za definiranje novog modela GPS ionosferskog kašnjenja, utemeljenog na praćenju dinamike GPS ionosferskog kašnjenja. Na kraju, predlaže se opći kompozitni model za određivanje vrijednosti GPS ionosferskog kašnjenja, koji uvažava regionalne posebnosti stanja ionosfere. Predloženi model primjenjiv je u svim uvjetima svemirskog vremena.

Abstract (english)

Here the problem of the impact of space weather and ionospheric conditions on ionospheric delay of the satellite navigation system signals is addressed. First, the space weather term is defined, along with the parameters describing its conditions. The process of ionospheric layer generation is presented, and related parameters describing the conditions of the ionosphere defined. The ionospheric models describing the relationship between the space weather and the ionosphere are discussed. The existing standard GPS ionospheric delay model is presented. Limitations and drawbacks of existing models in relation to the impact of the conditions and dynamics of space weather are analysed. The impact of extreme space weather and ionospheric disturbances on GPS ionospheric delay is analysed, based on particular case of extreme space weather and ionospheric disturbances observed during October and November 2003, as experienced in Republic of Croatia. The true values of GPS ionospheric delays for the period in question are extracted from raw GPS pseudorange measurements taken at the reference station Osijek, Croatia. The GPS ionospheric delay dynamics is analysed, and the correlation comparison with the space weather and the ionospheric conditions development examined. The results of the analysis form the foundation for a new GPS ionospheric delay model definition, established upon the monitoring of true GPS ionospheric delay dynamics. Finally, the general composite model for GPS ionospheric delay estimation is proposed, which takes into account the local and the regional characteristics of the ionosphere. Proposed model uses a present state of the space weather conditions as an input, and is completely applicable in all space weather conditions.

• Keywords: satelitsko određivanje položaja; ionosfersko kašnjenje; svemirsko vrijeme; ionosferska oluja; dinamika vremenskih nizova; matematički model; korekcija; kompozitni model
• Keywords (english): satellite positioning; ionospheric delay; space weather; ionospheric storm; time series dynamics; mathematical model; correction estimation; general composite model
• Language: croatian
• URN:NBN: urn:nbn:hr:168:832855
• Study programme: Title: Doctoral study programme "Electrical Engineering and Computing"; Study programme type: university; Study level: postgraduate; Academic / professional title: doktor/doktorica znanosti, po-dručje tehničkih znanosti (doktor/doktorica znanosti, po-dručje tehničkih znanosti)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2020-03-24 13:58:32