Naslov
Assessment of Galileo satellite system contribution in the modernization of CROPOS

Autori
Šugar, Danijel ; Bačić, Željko ; Nevistić, Zvonimir

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, pp prezentacija, znanstveni

Skup
14th Baška GNSS Conference: Technologies, Techniques and Applications across PNT & 1st Workshop on Smart Blue and Green Maritime Technologies

Mjesto i datum
Online ; Baška, Hrvatska, 10.05.2021. - 12.05.2021

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Galileo, CROPOS, services, modernization, static positioning, kinematic positioning

Sažetak
CROPOS as Croatian national permanent GNSS network was established in 2008. At that time the network consisted of 30 stations evenly distributed across national territory at an average distance of 70 km between stations providing observations of two fully operational global navigation satellite systems: GPS and GLONASS. In the meantime, CROPOS as a system was enlarged, updated, and improved: three stations set up at Croatian territory were added, control center was updated and 18 stations belonging to permanent GNSS network from neighboring countries were added to a system bringing the number of stations included in the networked solution up to 51. Within a project supported by the EU, in 2019 CROPOS was modernized where all 33 stations were equipped with new Trimble’s GNSS receivers and antennas providing observations of GPS, GLONASS, Galileo, and BeiDou satellite systems. CROPOS as a system provides three services: two real-time services (DPS and VPPS) and one service for post-processing (GPPS). The VPPS (networked solution of phase observation) and GPPS services which are widely accepted and used by a geodetic surveying community in Croatia have benefited from the modernization of CROPOS. To assess the contribution of the Galileo satellite system to the feasibility and performance of VPPS and GPPS services, within a diploma thesis on the Chair of Satellite Geodesy of the Faculty of Geodesy, in July 2020 were carried out field activities where a brand new Trimble’s GNSS R12 receiver providing support for all systems was used. After a detailed mission planning looking for the time windows with favorable (more visible satellites, low PDOP) and less favorable (few visible satellites, high PDOP) Galileo satellites visibility, field observations were carried out according to the following pattern: two adjacent kinematic sessions ((VPPS (all systems), VPPS (Galileo only)) followed by one static session (GPPS). According to the described pattern, GNSS observation sessions were carried out for the preplanned time windows. Each static session was processed (baseline processing and network adjustment) along with data from GPPS two times: firstly with all constellation data (GPS, GLONASS, Galileo, BeiDou), secondly with Galileo-only observations. Additionally, two daily static solutions were obtained: one with all satellite data, the other one with Galileo-only data. A static daily solution based on all constellation data was regarded as a reference for the comparison of coordinates obtained kinematically by the VPPS (all constellation solution and Galileo-only solution). Although the Galileo system is currently being built towards a Full Operational Capability declaration, it is already now capable of coordinates determination within the declared accuracy of CROPOS’s VPPS and GPPS. Due to the Galileo system under construction, mission planning is still the main prerequisite for the provision of results within a declared accuracy of CROPOS’s services. Of course, this is something that we have already seen in the early stages of GPS. Nevertheless, the Galileo system along with the BeiDou system implemented in CROPOS through its modernization has contributed to the overall availability and robustness of the system.

Izvorni jezik
Engleski

Znanstvena područja
Geodezija

POVEZANOST RADA