Title Prilog unaprjeđenju modeliranja zenitne komponente troposferskog kašnjenja satelitskih signala za određivanje korisničkog položaja sustava GLONASS Title (english) Contribution to the modelling of the tropospheric delay zenith component in GLONASS satellite positioning Author Mario Bakota Mentor Serđo Kos (mentor)Mentor David Brčić (komentor)Committee member Irena Jurdana (predsjednik povjerenstva)Committee member Danko Kezić (član povjerenstva)Committee member Jasmin Ćelić (član povjerenstva)Committee member Sanjin Valčić (član povjerenstva)Granter University of Rijeka Defense date and country 2022-04-06, Croatia Scientific / art field, TECHNICAL SCIENCES Universal decimal classificationUDC ) 55 - Geology. Meteorology. Hydrology 654 - Telecommunication and telecontrol 656.6 - Transport by water Abstract U ukupnoj greški položaja određenog satelitskim navigacijskim sustavima atmosfera sudjeluje s greškama uzrokovanim slojevima ionosfere i troposfere. Troposfera se smatra neutralnim medijem zbog istog učinka na faze signala vala nosioca i signala informacije. Greška položaja uzrokovana troposferskim djelovanjem (zajedničkog naziva troposfersko kašnjenje) mora se procijeniti prilikom određivanja položaja ili naknadno odrediti upotrebom vanjskih troposferskih popravaka. Najvažniji elementi koji
... More uzrokuju troposfersko kašnjenje jesu atmosferski plinovi, tlak, temperatura te količina vode u atmosferi. Učinak troposferskog kašnjenja odvojeno se promatra u zenitnom smjeru te u nagibnom smjeru dolaznog satelitskog navigacijskog signala. Dodatno, troposfersko kašnjenje može se promatrati i s obzirom na atmosferske uzroke pri čemu se odvojeno promatraju hidrostatski (suhi) i nehidrostatski (mokri) uzroci. Kretanje troposferskog kašnjenja pokazuje dnevne, sezonske i godišnje zakonitosti. Na tim spoznajama razvijen je niz modela popravaka troposferskog kašnjenja različitog pristupa: samo u zenitnom smjeru po suhim i/ili mokrim uzrocima, odvojena funkcija mapiranja za nagibne smjerove po suhim i/ili mokrim uzrocima ili zajednički cjeloviti model. U disertaciji je predložen model temeljen na Saastamoinenovu modelu zenitnog troposferskog kašnjenja. Model je razvijen na temelju položajnih zapisa satelitskog navigacijskog sustava GLONASS te odgovarajućih meteoroloških ulaznih podataka unutar jedne godine s trima lokacijama. Predloženi model definira troposfersko odstupanje odvojeno za svaku položajnu os. Rezultati pokazuju da je predloženim modelom ostvarena statistička ravnoteža položajnih odstupanja GLONASS-a u funkciji zenitne komponente troposferskog kašnjenja. Provedenog verifikacija (na trima lokacijama u Republici Hrvatskoj unutar dvogodišnjeg razdoblja) pokazuje da predloženi model smanjuje zenitnu komponentu troposferskog kašnjenja čime poboljšava točnost položaja. Time je potvrđena prikladnost upotrebe predloženog modela na promatranom području te na širim područjima sličnog klimatskog profila. Vrednovanju predloženog modela pristupilo se s obzirom na početna ograničenja, polučene rezultate točnosti te na ostvarene spoznaje o troposferskoj dinamici promatranog područja. Uputilo se na potencijal praktične i znanstvene primjene ukupnih rezultata istraživanja. Prilagodljivost predloženog modela, uz istovremeno smanjivanje početnih ograničenja, predstavlja osnovu za buduća istraživanja troposferskog kašnjenja. Less Abstract (english) In the overall position error determined by the satellite navigation systems, the atmosphere participates with errors caused by the ionosphere and troposphere layers. The troposphere is considered to be a neutral medium due to the same effect on the carrier phase and information signal phase. The position error caused by tropospheric effect (commonly called tropospheric delay) must be assessed while determining the position or subsequently determined using external tropospheric corrections.
... More The most important elements that cause tropospheric delay are atmospheric gases, pressure, temperature and the amount of water in the atmosphere. The effect of tropospheric delay is observed separately in the zenith direction and in the slant direction of the incoming satellite navigation signal. Additionally, tropospheric delay can also be observed with regard to atmospheric causes, with hydrostatic (dry) and non-hydrostatic (wet) causes being observed separately. The movement of tropospheric delays shows daily, seasonal and annual regularities. Based on these findings, a number of tropospheric delay models of different approaches have been developed in the zenith direction only for dry and / or wet causes, a separate mapping function for slant directions for dry and / or wet causes, or a common overall model. In the dissertation, a model based on the Saastamoinen model of zenith tropospheric delay has been proposed. The model was developed based on the position records of the GLONASS satellite navigation system and appropriate meteorological input records within one year with three locations. The proposed model defines the tropospheric deviation separately for each position coordinate. The results show that the statistical equilibrium of positional GLONASS deviations in a function of the zenith component of the tropospheric delay has been achieved by the proposed model. The verification carried out (at three locations in the Republic of Croatia within a two-year period) shows that the proposed model reduces the zenith component of the tropospheric delay and thus improves the accuracy of the position. This confirmed the suitability of using the proposed model in the observed area and in wider areas of similar climate profile. The evaluation of the proposed model has been approached in the view of the initial limitations, the obtained accuracy results and the realized knowledge about the tropospheric dynamics of the observed area. The potential of practical and scientific application of the overall research results has been pointed out. The adaptability of the proposed model while reducing initial restrictions represents the basis for future tropospheric delay researches. Less Keywords
hidrostatsko kašnjenje
nehidrostatsko kašnjenje
funkcija preslikavanja
standardna atmosfera
statistička ravnoteža
Saastamoinenov model zenitnog troposferskog kašnjenja
radionavigacijski satelitski sustav GLONASS
Keywords (english)
hydrostatic delay
non-hydrostatic delay
mapping function
standard atmosphere
statistical equilibrium
Saastamoinen model of zenith tropospheric delay
GLONASS radionavigation satellite system
Language croatian URN:NBN urn:nbn:hr:187:367377 Promotion 2022-05-19 Study programme Title: Postgraduate (doctoral) university study programme - Maritime Studies Type of resource Text Extent <X>, 169, 61 listova : graf. prikazi ; 31 cm File origin Born digital Access conditions Open access Terms of use Created on 2022-11-03 08:06:10
