Investigation of reliability of the variance covariance matrices obtained from GIPSY-OASIS II v6.4 software for precise point positioning

Year 2019, Volume: 6 Issue: 2, 75 - 86, 01.11.2019

Bahattin Erdoğan , Orhan Kayacık , Ali Hasan Doğan

https://doi.org/10.9733/JGG.2019R0007.T

Abstract

In recent years Precise
Point Positioning (PPP) technique is one of the most important subjects in
Geomatic Engineering. PPP technique needs only one Global Navigation Satellite
Systems (GNSS) receiver thus users have preferred it instead of traditional
relative positioning technique for several applications. Nowadays, scientific
software generally has been used for PPP solutions and the Variance covariance
(VCV) matrices estimated from software are very optimistic. The formal errors
estimated from VCV matrices have major effects on statistical interpretation.
VCV matrices derived from GNSS processing software play important role for
deformation analysis and scientists sometimes need to scale VCV matrices. In
this study, 10 continuously operating International GNSS Service (IGS)
reference stations have been considered for 11 days dated 2014. All points have
been analyzed by GIPSY-OASIS II v6.4 scientific software. It is aimed to
estimate scale factor for the PPP results obtained from GIPSY-OASIS II v6.4
with considering different session durations as 2, 4, 6, 8, 12 and 24 hours.
According to the results, the values of the scale factors raise depending on
the raises in respect of session duration.

Keywords

GIPSY-OASIS II v6.4, Precise point positioning, Variance covariance matrix, Scale factor, Reliability

Hassas mutlak nokta konumlamada GIPSY-OASIS II v6.4 yazılımı ile elde edilen varyans kovaryans matrisinin güvenirliğinin araştırılması

Abstract

Hassas Mutlak Konum
Belirleme (Precise Point Positioning - PPP) tekniği, harita/geomatik
mühendisliği uygulamalarında son yıllarda öne çıkan önemli konulardan
birisidir. PPP tekniğinde konumu belirlenecek noktada yalnızca bir tek Küresel
Navigasyon Uydu Sistemleri (Global Navigation Satellite Systems (GNSS))
alıcısının kullanılması yeterlidir. Bu nedenle kullanıcılar bu tekniği birçok
uygulamada geleneksel bağıl konumlama yöntemine göre tercih etmektedirler. PPP
tekniği ile yapılan çalışmalarda veri değerlendirme ve analiz aşamalarında
günümüzde genellikle bilimsel yazılımlar kullanılmaktadır. Bu yazılımlardan
elde edilen Varyans kovaryans (VKV) matrisleri ise çok iyimser sonuçlar
vermektedir. VKV matrislerinden hesaplanan değerler istatistiksel
yorumlamalarda önemli etkiye sahip unsurlardır. GNSS veri değerlendirmesi
sonucunda elde edilen VKV matrisleri deformasyon analizi gibi jeodezik
çalışmalarda kullanılmaktadır. Bu bağlamda araştırmacılar VKV matrislerini
ölçekleme ihtiyacı hissetmektedirler. Bu çalışmada, Uluslararası GNSS Servis
(International GNSS Service – IGS) ağına ait 10 adet sürekli gözlem yapan sabit
referans istasyonlarının, 2014 yılına ait 11 günlük verileri GIPSY-OASIS II
v6.4 bilimsel yazılımı kullanılarak PPP tekniği ile analiz edilmiştir. 2, 4, 6,
8, 12 ve 24 saatlik gözlem süreleri için GIPSY-OASIS II v6.4 PPP sonuçlarından elde
edilen VKV matrislerine ait ölçek faktörü kestirilmesi amaçlanmıştır. Analiz
sonuçlarına göre ölçek faktörü değerlerinin gözlem süresi arttıkça büyüdüğü
gözlenmiştir.

Keywords

Hassas mutlak konum belirleme, GIPSY-OASIS II v6.4, Varyans kovaryans matrisi, Ölçek faktörü, Güvenirlik

References

• Ananga, N., Coleman, R., & Rizos, C. (1994). Variance-covariance estimation of GPS networks. Bulletin géodésique, 68(2), 77-87.
• Blewitt, G. (1997). Basics of the GPS technique: observation equations. Geodetic applications of GPS, 10-54.
• Calais, E., Han, J. Y., DeMets, C., & Nocquet, J. M. (2006). Deformation of the North American plate interior from a decade of continuous GPS measurements. Journal of geophysical research: solid earth, 111(B6).
• Çetin, S., Aydın, C., & Doğan, U. (2018). Comparing GPS positioning errors derived from GAMIT/GLOBK and Bernese GNSS software packages: A case study in CORS-TR in Turkey. Survey Review, 1-11.
• Dixon, K. (2006). StarFire: A global SBAS for sub-decimeter precise point positioning. In Proceedings of ION GNSS (pp. 26-29).
• Doğan, U., Uludağ, M., & Demir, D. O. (2014). Investigation of GPS positioning accuracy during the seasonal variation. Measurement, 53, 91-100.
• Doğan, A. H., Tunalıoğlu, N., Erdoğan, B., & Öcalan, T. (2018). Evaluation of the GPS Precise Point Positioning technique during the 21 July 2017 Kos-Bodrum (East Aegean Sea) Mw 6.6 earthquake. Arabian Journal of Geosciences, 11(24), 775.
• Eckl, M. C., Snay, R. A., Soler, T., Cline, M. W., & Mader, G. L. (2001). Accuracy of GPS-derived relative positions as a function of interstation distance and observing-session duration. Journal of geodesy, 75(12), 633-640.
• Erdoğan, B., & Doğan, A. H. (2019). Scaling of the variance covariance matrix obtained from Bernese software. Acta Geodaetica et Geophysica, 2(54), 197-211.
• Gao, Y., & Shen, X. (2001). Improving ambiguity convergence in carrier phase-based precise point positioning. In Proceedings of the 14th international technical meeting of the Satellite Division of the Institute of Navigation (ION GPS 2001), 1532-1539.
• Gao, Y., Wojciechowski, A., & Chen, K. (2005). Airborne kinematic positioning using precise point positioning methodology. Geomatica, 59(1), 29-36.
• Geirsson, H. (2003). Continuous GPS measurements in Iceland 1999 - 2002 (Yüksek Lisans Tezi). University of Iceland, Akureyri, İzlanda.
• Geng, J., Teferle, F. N., Meng, X., & Dodson, A. H. (2010). Kinematic precise point positioning at remote marine platforms. GPS solutions, 14(4), 343-350.
• Hampel, F. R., Ronchetti, E. M., Rousseeuw, P. J., & Stahel, W. A. (2011). Robust statistics: the approach based on influence functions. John Wiley & Sons.
• Han, S., & Rizos, C. (1995). Standardisation of the variance-covariance matrix for GPS rapid static positioning. Geomatics Research Australasia, 37-54.
• Hekimoğlu, Ş. (2005). Do robust methods identify outliers more reliably than conventional test for outlier. Zeitschrift für Vermessungwesen, 3, 174-180.
• Kashani, I., Wielgosz, P., & Grejner-Brzezinska, D. A. (2004). On the reliability of the VCV Matrix: A case study based on GAMIT and Bernese GPS Software. GPS Solutions, 8(4), 193-199.
• Kedar, S., Hajj, G. A., Wilson, B. D., & Heflin, M. B. (2003). The effect of the second order GPS ionospheric correction on receiver positions. Geophysical Research Letters, 30(16).
• Kouba, J., & Héroux, P. (2001). Precise point positioning using IGS orbit and clock products. GPS solutions, 5(2), 12-28.
• Larson, K. M., & Miyazaki, S. I. (2008). Resolving static offsets from high-rate GPS data: the 2003 Tokachi-oki earthquake. Earth, planets and space, 60(8), 801-808.
• Li, B., Shen, Y., & Lou, L. (2011). Efficient estimation of variance and covariance components: a case study for GPS stochastic model evaluation. IEEE Transactions on Geoscience and Remote Sensing, 49(1), 203-210.
• Li, B., Lou, L., & Shen, Y. (2015). GNSS elevation-dependent stochastic modeling and its impacts on the statistic testing. Journal of Surveying Engineering, 142(2), 04015012.
• McClusky, S., Balassanian, S., Barka, A., Demir, C., Ergintav, S., Georgiev, I., ... & Kastens, K. (2000). Global Positioning System constraints on plate kinematics and dynamics in the eastern Mediterranean and Caucasus. Journal of Geophysical Research: Solid Earth, 105(B3), 5695-5719.
• Nocquet, J., Calais, E., & Nicolon, P. (2002). Reference frame activity: Combination of National (RGP) and Regional (REGAL) Permanent Networks Solutions with EUREF-EPN and the ITRF2000. In Proceedings of The EUREF 2002 Symposium, 398-404.
• Ohta, Y., Meilano, I., Sagiya, T., Kimata, F., & Hirahara, K. (2006). Large surface wave of the 2004 Sumatra-Andaman earthquake captured by the very long baseline kinematic analysis of 1-Hz GPS data. Earth, planets and space, 58(2), 153-157.
• Ohta, Y., Ohzono, M., Miura, S., Iinuma, T., Tachibana, K., Takatsuka, K., Miyao, K., Sato, T., & Umino, N. (2008). Coseismic fault model of the 2008 Iwate-Miyagi Nairiku earthquake deduced by a dense GPS network. Earth, planets and space, 60(12), 1197-1201.
• Öcalan, T. (2015). GNSS Ağlarında GPS Hassas Nokta Konumlama (GPS-PPP) Tekniği Yaklaşımlı Çözümler (Doktora Tezi). Yıldız Teknik Üniversitesi, Fen Bilimleri Enstitüsü, İstanbul, Türkiye.
• Pope, A. J. (1976). The statistics of residuals and the detection of outliers (No. NOS-65-NGS-1).
• Reilinger, R., McClusky, S., Paradissis, D., Ergintav, S., & Vernant, P. (2010). Geodetic constraints on the tectonic evolution of the Aegean region and strain accumulation along the Hellenic subduction zone. Tectonophysics, 488(1-4), 22-30.
• Rizos, C., Janssen, V., Roberts, C., & Grinter, T. (2012). Precise point positioning: is the era of differential GNSS positioning drawing to an end?
• Soler, T., Michalak, P., Weston, N. D., Snay, R. A., & Foote, R. H. (2006). Accuracy of OPUS solutions for 1-to 4-h observing sessions. GPS solutions, 10(1), 45-55.
• Şanlı, D. U., & Engin, C. (2009). Accuracy of GPS positioning over regional scales. Survey Review, 41(312), 192-200.
• Tekiç, S. (2009). Accuracy Of GPS Precise Point Positioning (PPP) (Yüksek Lisans Tezi). Boğaziçi Universitesi, Deprem Araştırma Enstitüsü, İstanbul, Türkiye.
• Tut, I., Şanlı, D. U., Erdoğan, B., & Hekimoğlu, Ş. (2013). Efficiency of BERNESE single baseline rapid static positioning solutions with search strategy. Survey review, 45(331), 296-304.
• Wang, G. Q. (2013). Millimeter-accuracy GPS landslide monitoring using Precise Point Positioning with Single Receiver Phase Ambiguity (PPP-SRPA) resolution: a case study in Puerto Rico. Journal of geodetic science, 3(1), 22-31.
• Wessel, P., & Smith, W. H. (1995). New version of the generic mapping tools. Eos, Transactions American Geophysical Union, 76(33), 329-329.
• Zumberge, J. F., Heflin, M. B., Jefferson, D. C., Watkins, M. M., & Webb, F. H. (1997). Precise point positioning for the efficient and robust analysis of GPS data from large networks. Journal of geophysical research: solid earth, 102(B3), 5005-5017.
• URL-1: https://www.spaceweatherlive.com/en/archive, (Erişim Tarihi: 12 Mart 2017).
• URL-2: https://gipsy-oasis.jpl.nasa.gov/gipsy/docs/GD2P_PPP.pdf, (Erişim Tarihi: 12 Mart 2017).