Model nespecifičnoga dnevnog hoda ionosferskog kašnjenja signala za satelitsko određivanje položaja

Satellite positioning signal ionospheric delay has been identified as a single major
contributor in total satellite positioning error budget. Daily dynamics of ionospheric
delay are described globally by utilising the GPS standard (Klobuchar) ionospheric
model. In this doctoral thesis, a regional ionospheric delay correction model has been
proposed. The model is based on observed daily pattern ionospheric delay non-specific
regularities, which are occuring under specified conditions; during quiet space weather,
undisturbed ionosphere, in summer months period and at middle geographic latitudes.
The local ionospheric delay dynamics are the reason and a motivation for conducted
research, which was carried out aiming at GNSS services improvement and system
performance. The model is developed on the basis of measured values of ionospheric
delay. These values were derived from code and phase pseudorange observables from
Adriatic region reference IGS stations. The model has been verified in time periods
where defined conditions of satellite positioning signal propagation environment were
prevailing. Obtained values were compared with actual ionospheric delay values, as well
as with ionospheric delay values obtained with the Klobuchar ionospheric correction
model. The proposed model has been tested in three different locations in the Adriatic
region, in years 2006 and 2007. The results showed that, under specified conditions and
controlling parameters, proposed ionospheric model provides more accurate
ionospheric delay corrections compared to the Klobuchar model. The proposed model's
applicability in the Adriatic region and surrounding has been confirmed. Model
properties have been discussed from the accomplishment, advantages and limitations
aspect. The potential of the model's scientific and practical appliance is presented, along
with thesis research results. A model error analysis and error causes will set guidelines
for further research activities regarding local and global ionospheric dynamics
conditions, as well as solar and geomagnetic activity exploration.