Real-Time Coseismic Displacement Retrieval Based on Temporal Point Positioning with IGS RTS Correction Products

Abstract

With the rapid development of the global navigation satellite system (GNSS), high-rate GNSS has been widely used for high-precision GNSS coseismic displacement retrieval. In recent decades, relative positioning (RP) and precise point positioning (PPP) are mainly adopted to retrieve coseismic displacements. However, RP can only obtain relative coseismic displacements with respect to a reference station, which might be subject to quaking during a large seismic event. While PPP needs a long (re)convergence period of tens of minutes. There is no convergence time needed in the variometric approach for displacements analysis standalone engine (VADASE) but the derived displacements are accompanied by a drift. Temporal point positioning (TPP) method adopts temporal-differenced ionosphere-free phase measurements between a reference epoch and the current epoch, and there is almost no drift in the displacement derived from TPP method. Nevertheless, the precise orbit and clock products should be applied in the TPP method. The studies in recent years are almost based on the postprocessing precise orbits and clocks or simulated real-time products. Since 2013, international GNSS service (IGS) has been providing an open-access real-time service (RTS), which consists of orbit, clock and other corrections. In this contribution, we evaluated the performance of real-time coseismic displacement retrieval based on TPP method with IGS RTS correction products. At first, the real-time precise orbit and clock offsets are derived from the RTS correction products. Then, the temporal-differenced ionosphere-free (IF) combinations are formed and adopted as the TPP measurements. By applying real-time precise orbit and clock offsets, the coseismic displacement can be real-timely retrieved based on TPP measurements. To evaluate the accuracy, two experiments including a stationary experiment and an application to an earthquake event were carried out. The former gives an accuracy of 1.8 cm in the horizontal direction and 4.1 cm in the vertical direction during the whole period of 15-min. The latter gives an accuracy of 1.2 cm and 2.4 cm in the horizontal and vertical components, respectively.

Galileo High Accuracy Service in Real-Time PNT, Geoscience and Monitoring Applications

“…Subcm land deformations in the mining areas are detectable [14]. Coseismic displacement waveforms are retrieved with horizontal and vertical accuracy of 1.2 cm and 2.4 cm, respectively [15]. Time transfer uncertainty with real-time PPP is better than 0.3 ns [16].…”

Investigation of Real-Time GNSS VADASE Approach Capability of Capturing Vertical Dynamic Movements

“…Ayrıca GNSS alıcılarının veri işleme ve depolama kapasitesindeki gelişmeler, kullanılan yöntemlere dayalı geliştirilen algoritmalar ve gerçek zamanlı uydu yörünge ve saat düzeltme bilgisi veri akışının sağlanması sonucu anlık oluşan dinamik yer değiştirmeleri gerçek zamanlı Hassas Nokta Konumlama (RT-PPP) yöntemiyle de değerlendirilmiştir (Hadas and Bosy 2015, Elsobeiey and Al Harbi 2016, Krzan and Przestrzelski 2016, El-Mowafy et al 2016, Alcay and Turgut 2017, 2019, Alcay 2019, Alkan ve Mutlu 2022. Bu yöntem deprem, tsunami, rüzgâr ve volkanik patlama gibi doğal olayların oluşturmuş olduğu şiddetli yüksek dinamik hareketlerin anlık olarak izlenilmesi ve değerlendirilmesini sağlamıştır (Martin et al 2015, Zhang et al 2021. Bununla birlikte bağıl konum belirleme yönteminin sabit noktaya bağlı olması, sonradan değerlendirme (PP)-PPP tekniğinde kullanılan uydu yörünge ve saat düzeltme ürünlerinin belirli bir zaman gecikmesiyle yayınlanması ve RT-PPP yönteminde anlık internet servisine dayalı kesintiler, gerçek zamanlı ürünlerin Gerçek Zamanlı Servis (RTS) kaynaklı gecikmeleri, bu yöntemlerin gerçek zamanlı dinamik hareketleri izlemede kullanılabilirliğini sınırlandırmaktadır.…”

High-rate real-time PPP for dynamic motion detection in vertical direction

“…In the studies, the performance of the Real Time (RT)-PPP method and the correction products used were tested by monitoring the displacements that occur in natural events such as earthquakes and tsunamis. (Hadas and Bosy, 2015;Krzan and Przestrzelski, 2016;Elsobeiey and Al Harbi, 2016;El-Mowafy et al, 2016;Alcay and Turgut, 2017;Alcay, 2019;Takahaski et al, 2014, Tu et al, 2017, El-Mowafy and Deo, 2017Li et al, 2019;Li et al, 2014;Zheng et al, 2019;Zhang et al, 2021). This method, which is also used in deformation monitoring of engineering structures, has been emphasized as an alternative method to the RP method (Martin et al, 2015;Tang et al, 2017).…”

“…However, the use of these products has been tested for near real-time rapid hazard assessment in order to detect the oscillations caused by the motions of the earth's crust in the structures and the damage to the structure. It has been tested that under real-time conditions, correction products produced from IGC01 can be detected at the centimeter or even millimeter level in the detection of earthquake-induced surface wave motions (Li et al, 2019;Li et al, 2014;Zheng et al, 2019;Zhang et al, 2021).…”