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Browsing by Subject "PPP"

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  • thumbnail.journal.alt
    Item type:Article, Access status: Open Access ,
    Accuracy assessment of a variety of GPS data processing, online services and software
    (Wydawnictwa AGH, 2021) Mohammed, Israa H.; Ataiwe, Tariq N.; Al Sharaa, Hisham
    The processing of GPS observations in precise positioning is complex and requires professional surveyors since it must be carried out after each static measurement. In GPS network adjustment, the obtaining of the correct coordinates of the determined point is possible after determining the components of GPS vectors and aligning the networks of these vectors, while PPP requires the availability of precise products for the reference satellites orbits and clock. For that reason, surveyors can take advantage of free online GPS data processing. In this paper, the authors compare the results obtained from different sources of free online GPS data processing (AUSPOS, OPUS, CenterPoint RTX, APPS, MagicGNSS, CSRS-PPP, GAPS, and SCOUT) in terms of their accuracy, availability, and operation. This is then compared with free GPS processing soft - ware (gLAB and RTKLIB), and finally with commercial software (TBC Trimble Business Center). The results show that online processing services are more accurate than offline processing software, which indicates the strength of their algorithms and processes. The CSRS-PPP online service had the best results. The difference between the relative solution of AUSPOS and OPUS, and CSRS-PPP is insignificant.
  • thumbnail.journal.alt
    Item type:Article, Access status: Open Access ,
    Preliminary analysis of the applicability of the GPS PPP method in geodynamic studies
    (Wydawnictwa AGH, 2020) Pelc-Mieczkowska, Renata
    GNSS station movements as an indicator of the movement of the Earth's crust are determined by many researchers with the use of various position and trend determination methods. One of such methods is PPP method which allows the determination of a trend for the station without a correlation (direct determination of the position of each station separately). To achieve accuracy comparable with relative positioning, there is the need to use external, high‑precision data or models (e.g. precise satellite orbits and clocks, ionosphere and tropo‑ sphere models, etc.) while the PPP method is applied. The main purpose of the presented research is preliminary analyses of the results of processing daily GPS observations from permanent stations with the use of the PPP method. Daily GPS observational data in RINEX format have been acquired from a total of nine selected GNSS permanent stations from the Polish ASG EUPOS and the Ukrainian UA-EUPOS/ZAKPOS systems. As external data for PPP solutions JPL products have been used. A seven‑year time series was created for each station.