Barış KARADENİZ, Mert BEZCİOĞLU, Ömer Faruk BİLGEN, Cemal Özer YİĞİT

GPS/Galileo PPP-AR ve PPP Yöntemlerinin Doğruluklarının Gözlem Süresi ve Uydu Kombinasyonları Açısından İncelenmesi

Bu çalışmada farklı enlemlerde seçilen üç farklı Uluslararası GNSS Servisi (IGS) istasyonunun ardışık 15 günlük GPS/Galileo gözlem verileri kullanılmış, elde edilen bu gözlemler, hem geleneksel-PPP hem de PPP-AR teknikleri kullanılarak statik modda değerlendirilmiştir. Kısa ve uzun ölçü süresinin yöntemler üzerindeki etkisini değerlendirmek için, üç farklı istasyondan elde edilen gözlem dosyaları 0.75, 1, 1.5, 2, 3, 4 ve 24 saatlik verilere ayrılmış, Galileo uydu gözlemlerinin GPS uydu gözlemlerine katkısını incelemek için PPP ve PPP-AR yöntemleri sadece-GPS ve GPS/Galileo uydu kombinasyonları açısından da incelenmiştir. Sonuçlar gözlem sürelerinin artması ile PPP yönteminde konum doğruluğunun arttığını ve PPP-AR tekniğinde ise faz başlangıç belirsizliğinin yanlış değere sabitlenme riskini azalttığını göstermiştir. Çalışmanın bulguları, PPP ve PPP-AR tekniklerinde Galileo uydu sisteminin GPS gözlemlerine dahil edilmesiyle konum doğruluğunun geliştiğini, PPP ve PPP-AR yöntemlerinin birbirleriyle karşılaştırıldıklarında ise PPP-AR yönteminin konum doğruluğunun genellikle tüm ölçü sürelerinde PPP yönteminden daha iyi çıktığı açıkça ifade edilmektedir.

Investigating the Accuracy of GPS/Galileo PPP-AR and PPP Methods In Terms of Observation Duration and Satellite Combinations

In this study, 15 consecutive days of GPS/Galileo observations of three different International GNSS Service (IGS) stations selected at different latitudes were used, and these observations were evaluated in static mode using both traditional-PPP and PPP-AR techniques. In order to evaluate the effect of short and long observation duration on discussed the methods, observation files obtained from three different stations were divided into 0.75, 1, 1.5, 2, 3, 4 and 24 hour data.In order to examine the contribution of Galileo satellite observations to GPS satellite observations, PPP and PPP-AR methods were also examined in terms of GPS-only and GPS/Galileo satellite combinations. The results showed that with the increase of the observation duration, the position accuracy increased in the PPP method and the risk of fixing wrong integer ambiguity in the PPP-AR technique was reduced. The findings of the study clearly state that in PPP and PPP-AR techniques, the inclusion of Galileo observations to GPS has improved the positioning accuracy, and when the PPP and PPP-AR methods are compared with each other, the horizontal positioning accuracy of the PPP-AR method is generally better than the PPP method at all observation periods.

PDF

___

Anquela, A.B., Martin, A., Berne, J.L., Padin, J., 2013. GPS+GLONASS Static and Kinematic PPP Results, A Case Study. Journal of Surveying Engineering, 139(1), 47-58.
Bulbul, S., Bilgen, B., Inal, C., 2021. The performance assessment of Precise Point Positioning (PPP) under various observation conditions. Measurement, 171, 108780.
Cai, C., Gao, Y., 2007. Precise point positioning using combined GPS and GLONASS observations. Journal of Global Positioning Systems, 6(1), 13-22.
Cai, C., Gao, Y., 2013. Modeling and assessment of combined GPS/GLONASS precise point positioning. GPS Solutions, 17(2), 223-236.
Choy, S., Bisnath, S., Rizos, C., 2017. Uncovering common misconceptions in GNSS Precise Point Positioning and its future prospect. GPS Solutions, 21, 13-22.
Dow, J.M., Neilan, R.E., Rizos, C., 2009. The international GNSS service in a changing landscape of global navigation satellite systems. Journal of Geodesy, 83(3–4), 191–198.
Gao, Y., 2006. Precise point positioning and its challenges, aided-gnss and signal tracking. Inside GNSS,1, 16–18.
Ge, M., Zhang, H., Jia, X., Song, S., Wickert, J., 2012. What is achievable with current COMPASS constellations ?, Proceedings of the 25th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2012), Nashville, TN, 331-339.
Geng, J., Guo, J., Meng, X., Gao, K., 2020. Speeding up PPP ambiguity resolution using triple-frequency GPS/BeiDou/Galileo/QZSS data. Journal of Geodesy, 94(6), 1-15.
Guo, F., Li, X., Zhang, X., Wang, J., 2017. Assessment of precise orbit and clock products for Galileo, BeiDou, and QZSS from IGS Multi-GNSS Experiment (MGEX). GPS Solutions, 21, 279-279.
Hackel, S., Steigenberger, P., Hugentobler, U., Uhlemann, M., Montenburck, O., 2013. Galileo orbit determination using combined GNSS and SLR observations. GPS Solutions, 19(1), 15-25.
Hofmann-Wellenhof, B., Lichtenegger, H., Wasle, E., 2008. GNSS-Global Navigation satellite Systems: GPS, GLONASS, Galileo & more. Springer, Wien, Newyork, 516.
Katsigianni, G., Loyer, S., Perosanz, F., 2019. PPP and PPP-AR Kinematic Post-Processed Performance of GPS-Only, Galileo-Only and Multi-GNSS. Remote Sensing, 11, 2477.
Koca, B., Ceylan, A., 2018. Uydu Konum Belirleme Sistemlerindeki(GNSS) Güncel Durum ve Son Gelişmeler. Geomatik, 3(1), 63-73.
Kouba, J. and Héroux, P., 2001. GPS Precise Point Positioning using IGS orbit products. GPS Solutions, 5(2), 12–28.
Li, M., Qu, L., Zhao, Q., Guo, J., Su, X., Li, X., 2014. Precise point positioning with the BeiDou navigation satellite system. Sensors, 14(1), 927-943.
Li, P., Zhang, X., Guo, F., 2017. Ambiguity resolved precise point positioning with GPS and BeiDou. Journal of Geodesy, 91, 25-40.
Li, X., Li, X., Yuan, Y., Zhang, K., Zhang, X., Wickert, J., 2018. Multi-GNSS phase delay estimation and PPP ambiguity resolution: GPS, BDS, GLONASS, Galileo. Journal of Geodesy, 92, 579-608.
Li, R., Zheng, S., Wang, E., Chen, J., Feng, S., Wang, D., Dai, L., 2020. Advances in BeiDou Navigation Satellite System (BDS) and satellite navigation augmentation Technologies. Satellite Navigation,1, 12.
Lou, Y., Zheng, F., Gu, S., Wang, C., Guo, H., 2016. Multi-GNSS precise point positioning with rawsingle-frequency and dual-frequency measurement models. GPS Solutions, 20, 849-862.
Montenbruck, O., Steigenberger, P., Khachikyan, R., Weber, G., Langley, R.B., Mervart, L., Hugentobler, U., 2014. IGS-MGEX: preparing the ground for multi-constellation GNSS science. Inside GNSS, 9(1), 42-49.
Neilan, R., Fisher, S., Khachikyan, R., Ceva, J., Craddock, A., Donnelly, N., Maggert, D., Walia, G., 2013. IGS technical report 2012 Central Bureau. IGS technical report, 13–18.
Pırtı, A., Hoşbaş, R.G., Şenel, B., Köroğlu, M., Bilim, S., 2021. Galileo uydu sistemi ve sinyal yapısı. Journal of Geomatics, 6(3), 207-216.
Psychas, D., Verhagen, S., Teunissen, P.J.G., 2020. Precision analysis of partial ambiguity resolution-enabled PPP using multi-GNSS and multi-frequency signals. Advances in Space Research, 66, 2075–2093.
Rizos, C., Montenbruck, O., Weber, R., Neilan, R., Hugentobler, U., 2013. The IGS MGEX experiment as a milestone for a comprehensive multi-GNSS service. Institute of Navigation, Honolulu, HI, 289-295.
Hobiger, T., Jakowski N., 2017. Handbook of Global Navigation Satellite Systems. Ed:Teunissen, P., Montenbruck, O., Springer, 59, 165-193.
Xia, F., Ye, S., Xia, P., Zhao, L., Jiang, N., Chen, D., Hu, G. 2019. Assessing the latest performance of Galileo-only PPP and the contribution of Galileo to Multi- GNSS PPP. Advances in Space Research, 63, 2784–2795.
Yigit, C.O., Gikas, V., Alcay, S., Ceylan, A., 2014. Performance evaluation of short to long term GPS, GLONASS and , GPS/GLONASS post-processed PPP. Survey Review, 46(3), 155-166.
Yigit, C.O., Kizilarslan, M., Caliskan, E., 2016. GPS-PPP ve GPS/GLONASS-PPP Yöntemlerinin Konum Belirleme Performanslarının Ölçü Süresine Bağlı Olarak Değerlendirilmesi. Electronic Journal of Map Technologies, 8(1), 23-29.
Yionoulis, S.M., 1998. The Transit Satellite Geodesy Program. Johns Hopkins University APL Technical Diagest, 19(1), Washington.
Zhao, Q., Guo, J., Li, M., Qu, L., Hu, Z., Shi, C., Liu, J., 2013. Initial results of precise orbit and clock determination for COMPASS navigation satellite system. Journal of Geodesy, 87(5), 475-486.
1- https://github.com/YizeZhang/Net_Diff(20.08.2021)
2-https://cddis.nasa.gov/archive/gnss/data/daily/2020/ (05.09.2021)
3-ftp://ftp.gfz-potsdam.de/pub/GNSS/products/mgex(30.07.2021)