Çoklu-GNSS çözümlerinin performansının internet tabanlı Trimble RTX servisi ile incelenmesi

Sezer, Gizem; Doğan, Ali Hasan; Erdoğan, Bahattin

doi:10.9733/jgg.2021r0003.t

Cited by 5 publications

(4 citation statements)

References 23 publications

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“…Hence, we applied the median approach to the PS points’ displacements to exclude outliers before taking averages in each epoch for each GNSS station. With a 50% breakdown point, the median approach is one of the most reliable outlier detection methods [ 20 , 25 , 26 ]. Additionally, the median and median absolute deviation (MAD) are more efficient in outlier detection than the mean and standard deviation.…”

Section: Resultsmentioning

confidence: 99%

“…This service uses precise orbits and clocks produced by Trimble RTX. The update rate of the products is 1 Hz [ 20 ]. For static positioning, the convergence time is 15 min [ 19 ].…”

Section: Methodsmentioning

confidence: 99%

“…We then transformed each campaign’s coordinates and covariance matrices to a topocentric coordinate system with respect to each station’s first epoch. Moreover, a 6 h observation session duration, as indicated by Sezer et al [ 20 ], employing the accuracy function provided by Saracoglu and Sanli [ 21 ], can yield millimeter-level accuracy.…”

Section: Methodsmentioning

confidence: 99%

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A Statistical Approach for the Integration of Multi-Temporal InSAR and GNSS-PPP Ground Deformation Measurements

Delen,

Sanli,

Abdikan

et al. 2023

Sensors

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Determining and monitoring ground deformations is critical for hazard management studies, especially in megacities, and these studies might help prevent future disaster conditions and save many lives. In recent years, the Golden Horn, located in the southeast of the European part of Istanbul within a UNESCO-protected region, has experienced significant changes and regional deformations linked to rapid population growth, infrastructure work, and tramway construction. In this study, we used Interferometric Synthetic Aperture Radar (InSAR) and Global Navigation Satellite System (GNSS) techniques to investigate the ground deformations along the Golden Horn coastlines. The investigated periods are between 2015 and 2020 and 2017 and 2020 for InSAR and GNSS, respectively. For the InSAR analyses, we used sequences of multi-temporal synthetic aperture radar (SAR) images collected by the Sentinel-1 and ALOS-2 satellites. The ground displacement products (i.e., time series and velocity maps) were then cross-compared with those achievable using the Precise Point Positioning (PPP) technique for the GNSS solutions, which can provide precise positions with a single receiver. In the proposed analysis, we compared the ground displacement velocities obtained by both methods by computing the standard deviations of the difference between the relevant observations considering a weighted least square estimation procedure. Additionally, we identified five circle buffers with different radii ranging between 50 m and 250 m for selecting the most appropriate coherent points to conduct the cross-comparison analysis. Moreover, a vertical displacement rate map was produced. The comparison of the vertical ground velocities derived from PPP and InSAR demonstrates that the PPP technique is valuable. For the coherent stations, the vertical displacement rates vary between −4.86 mm/yr and −23.58 mm/yr and −9.50 and −27.77 mm/yr for InSAR and GNSS, respectively.

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Section: Resultsmentioning

confidence: 99%

“…This service uses precise orbits and clocks produced by Trimble RTX. The update rate of the products is 1 Hz [ 20 ]. For static positioning, the convergence time is 15 min [ 19 ].…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A Statistical Approach for the Integration of Multi-Temporal InSAR and GNSS-PPP Ground Deformation Measurements

Delen,

Sanli,

Abdikan

et al. 2023

Sensors

View full text Add to dashboard Cite

show abstract

“…Her bir servis için konum doğrulukları incelendiğinde kaba hatalı sonuçların ortaya çıktığı görülmüştür.Servislerin kalitesinin belirlenebilmesi için konum doğruluklarının karesel ortalama hata (RMS) değerleri ile ilişkilendirilmesi işleminden önce uyuşumsuz ölçülerin veri kümesinden çıkarılması gerekmektedir. RMS değerlerinin hesaplanmasından önce uyuşumsuz ölçüler; klasik yöntemlerden ziyade %50 kırılma düzeyi ile en güvenilir robust yöntemlerinden biri olan Medyan yöntemi ile analiz edilmiştir(Hampel, Ronchetti, Rousseeuw, & Stahel, 2011;Sezer, Doğan, & Erdoğan, 2021). Medyan yöntemi Eşitlik 1 ile ifade edilmektedir.…”

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