Akıllı mobil telefonlardan elde edilen çift frekanslı ham GNSS gözlemleri ile PPP konum belirleme performansının araştırılması

Yıl 2021, Cilt: 8 Sayı: 2, 120 - 130, 01.11.2021

Caneren Gül , Ali Hasan Doğan , Taylan Öcalan

https://doi.org/10.9733/JGG.2021R0009.T

Öz

Akıllı mobil telefonların ham GNSS verilerinin erişilebilir hale gelmesi ve bu yönüyle işlenebilir olması, düşük maliyetli GNSS konum belirleme çalışmaları için inovasyon olmuştur. Mayıs 2018’de Xiaomi firması tarafından dünyanın ilk çift frekanslı GNSS çipine sahip Mi8 model telefonun piyasaya sürülmesi ise mühendislik uygulamaları için akıllı mobil telefonlarla konum belirlemedeki çalışmalara büyük bir ivme kazandırmıştır. Bu gelişim dinamiği dikkate alınarak gerçekleştirilen bu çalışmada iki gün tekrarlı ve iki saat süre ile toplanan Xiaomi Mi8 akıllı telefon statik GNSS gözlemleri, GipsyX ve RTKLIB yazılımları ile farklı uydu yükseklik açılarında epok epok kinematik olarak hassas mutlak nokta konum belirleme (Precise Point Positioning, PPP) yöntemi ile değerlendirilmiş, yatay konum doğrulukları hesaplanmıştır. Xiaomi Mi8’den elde edilen çift frekanslı GNSS gözlemlerinin PPP performansı, farklı uydu yükseklik açılarında incelenmiştir. Çözümler eş zamanlı gözlem yapan Topcon Hiper SR jeodezik alıcının bağıl konumlama çözümleri referans alınarak karşılaştırılmıştır. Elde edilen bulgular sonucunda RTKLIB çözümlerinin yatay konum doğruluğunun uydu yükseklik açısı ile ters orantılı olduğu, buna karşın GipsyX çözümlerinde bu bağlamda farklılıklar olduğu gözlemlenmiştir. Xiaomi Mi8 çift frekanslı GNSS gözlemlerinin PPP yöntemi ile değerlendirmesinde GipsyX çözümlerinin RTKLIB çözümlerinden daha yüksek doğrulukta sonuçlar ürettiği görülmüştür.

Anahtar Kelimeler

Akıllı mobil telefon, GNSS, PPP, Xiaomi Mi8, GipsyX, RTKLIB

Investigation of PPP performance with dual frequency raw GNSS observations obtained from smartphones

Öz

Being accessible and processible of the raw GNSS data of smartphones has been an innovation for low-cost GNSS positioning studies. With the release of world’s first smartphone with dual frequency GNSS chipset Mi8 by Xiaomi in May 2018, studies on smartphone-based positioning for engineering applications have gained great momentum. Considering these development dynamics, in this study, repeatedly collected Xiaomi Mi8 dual frequency static GNSS observations for two days in two-hour time span were processed using GipsyX and RTKLIB software with epoch by epoch kinematic Precise Point Positioning (PPP) method at different satellite elevation angles, and horizontal positioning accuracies were calculated. The PPP performance of dual frequency GNSS observations collected by Xiaomi Mi8 was investigated at different satellite elevation angles. The process outputs were compared with results analyzed by relative positioning method collected simultaneously with Topcon Hiper SR geodetic receiver by considering as a reference solution. According to the results, it was noted that the horizontal positioning accuracy of RTKLIB outputs has directly inverse relationship with increasing satellite elevation angles whereas GipsyX outputs have differences in this context. In the processing of Xiaomi Mi8 dual frequency observations with PPP method, it was concluded that GipsyX produced higher horizontal positioning accuracy than RTKLIB.

Anahtar Kelimeler

Smartphone, GNSS, PPP, Xiaomi Mi8, GipsyX, RTKLIB

Kaynakça

• Aggrey, J., Bisnath, S., Naciri, N., Shinghal, G., & Yang, S. (2019). Use of PPP processing for next-generation smartphone GNSS chips: key benefits and challenges. Proceedings of the 32nd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2019), 3862-3878.
• Banville, S., & Van Diggelen, F. (2016). Precise positioning using raw GPS measurements from Android smartphones. GPS world, 27(11), 43-48.
• Bertiger, W., Bar-Sever, Y., Dorsey, A., Haines, B., Harvey, N., Hemberger, D., Heflin, M., Lu, W., Moore, A.W., Murphy, D., Ries, P., Romans, L., Sibois, A., Sibthorpe, A., Szilagyi, B., Vallisneri, M., & Pascal, W. (2020). GipsyX/RTGx, a new tool set for space geodetic operations and research. Advances in Space Research, 66(3), 469-489.
• Chen, K., & Gao, Y. (2005). Real-time precise point positioning using single frequency data. Proceedings of the 18th international technical meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2005), 1514-1523.
• Chen, B., Gao, C., Liu, Y., & Sun, P. (2019). Real-time precise point positioning with a Xiaomi MI 8 android smartphone. Sensors, 19(12), 2835.
• Elmezayen, A., & El-Rabbany, A. (2019). Precise point positioning using world’s first dual-frequency GPS/GALILEO smartphone. Sensors, 19(11), 2593.
• Erdoğan, B., Karlıtepe, F., Öcalan, T., & Tunalıoğlu, N. (2018). Performance analysis of Real Time PPP for transit of Mercury. Measurement, 129, 358-367.
• Estey, L. H., & Meertens, C. M. (1999). TEQC: the multi-purpose toolkit for GPS/GLONASS data. GPS solutions, 3(1), 42-49.
• Héroux, P., Gao, Y., Kouba, J., Lahaye, F., Mireault, Y., Collins, P., Macleod, K., Tétreault, P., & Chen, K. (2004). Products and applications for Precise Point Positioning-Moving towards real-time. Proceedings of the 17th international technical meeting of the satellite division of The Institute of Navigation (ION GNSS 2004), 1832-1843.
• Kulikov, R., Chugunov, A., & Zamolodchikov, V. (2019). Investigation of collision warning possibilities by means of GNSS receivers of Android smartphones. IOP Conference Series: Materials Science and Engineering Vol. 695, No. 1, 12013.
• Lipatnikov, L. A., & Shevchuk, S. O. (2019). Cost Effective Precise Positioning with GNSS. The International Federation of Surveyors (FIG), No: 74.
• Öcalan, T., Erdoğan, B., Tunalıoğlu, N., & Durdağ, U. M. (2016). Accuracy investigation of PPP method versus relative positioning using different satellite ephemerides products near/under forest environment. Earth sciences research journal, 20(4), 1-9.
• Pathak, V., Thornwall, S., Krier, M., Rowson, S., Poilasne, G., & Desclos, L. (2003). Mobile handset system performance comparison of a linearly polarized GPS internal antenna with a circularly polarized antenna. IEEE antennas and propagation society international symposium. Digest. Held in conjunction with: USNC/CNC/URSI North American Radio Sci. Meeting Vol. 3, 666-669.
• Robustelli, U., Baiocchi, V., & Pugliano, G. (2019). Assessment of dual frequency GNSS observations from a Xiaomi Mi 8 Android smartphone and positioning performance analysis. Electronics, 8(1), 91.
• Siddakatte, R., Broumandan, A., & Lachapelle, G. (2017). Performance evaluation of smartphone GNSS measurements with different antenna configurations. Proceedings of the International Navigation Conference. 2007.
• Takasu, T. (2013). RTKLIB ver. 2.4. 2 Manual. RTKLIB: An Open Source Program Package for GNSS Positioning, 29-49.
• Wu, Q., Sun, M., Zhou, C., & Zhang, P. (2019). Precise point positioning using dual-frequency GNSS observations on smartphone. Sensors, 19(9), 2189.
• Zhang, X., Tao, X., Zhu, F., Shi, X., & Wang, F. (2018). Quality assessment of GNSS observations from an Android N smartphone and positioning performance analysis using time-differenced filtering approach. GPS Solutions, 22(3), 1-11.
• 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. J. Geophys. Res., 102( B3), 5005– 5017.
• URL-1: GSA GNSS Market Report 2019, Issue6, https://www.gsa.europa.eu/newsroom/news/european-gnss-agency-gsa-releases-6th-gnss-market-report, (Erişim Tarihi: 3 Şubat 2020).
• URL-2: Geo++RINEX Logger, https://play.google.com/store/apps/details?id=de.geopp.rinexlogger&hl=en, (Erişim Tarihi: 28 Ocak 2020).