A robotic total station (RTS) [or theodolite or positioning system (TPS)] was used for the first time to measure deflections of a short-span bridge in response passing trains. The RTS measurements aimed reflector which set on one midspans historical Gorgopotamos Bridge Greece permitted identify measurement noise (apparent displacements) up ±1.3 mm when no trains were passing, and with peaks 2.5–6 during intervals small larger passing. These results confirm previous experiments indicate that,...

After approximately 60 years of seismic quiescence within Santorini caldera, in January 2011 the volcano reawakened with a significant swarm and rapidly expanding radial deformation. The deformation is imaged by dense network 19 survey 5 continuous GPS stations, showing that as 21 2012, has extended laterally from point inside northern segment caldera about 140 mm at 180 mm/yr. A series spherical source models show not migrating significantly, but remains 4 km depth expanded 14 million m 3...

Structural Health Monitoring (SHM) is a relatively new branch of civil engineering that focuses on assessing the health status infrastructure, such as long-span bridges. Using broad range in-situ monitoring instruments, purpose SHM to help engineers understand behaviour structures, ensuring their structural integrity and safety public. Under Integrated Applications Promotion (IAP) scheme European Space Agency (ESA), feasibility study (FS) project used Global Navigation Satellite Systems...

The development of low-cost GNSS receivers broadens their applications, such as deformation monitoring, which have been performed routinely by survey-grade receivers. To evaluate the performance receivers, we assessed precision multi-GNSS in monitoring dynamic motion and developed methods using a closely-spaced dual receivers' system to enhance performance. In this study, both receiver/antennas were mounted on circular rotating device executing controlled periodic rotation. It was shown that...

The development of low-cost GNSS receivers with carrier-phase measurement capacity has led to low-budget applications higher accuracy and precision. Recent studies have mainly been carried out those for landslide monitoring achieved promising results. In this study, the performance two closely-spaced high-rate was assessed against robotic total station (RTS) geodetic receiver in dynamic response a major pedestrian suspension bridge at mid-span. Potential improvement by combination...

Abstract: Based on experimental evidence we explore the possibility of using GPS and robotic total stations (RTS) for measurements oscillations relatively rigid structures (modal frequencies up to 3–4 Hz). Our strategy was compare uni‐axial known characteristics with simultaneous recordings both RTS, analyze obtained time series determine amplitude frequency oscillations. The conclusion this study is that can record 4 Hz a minimum 5–10 mm an accuracy few millimeters, RTS peaks submillimeters...

The application of GPS in bridge monitoring aims to determine accurately and precisely the response deck towers estimate main characteristics (amplitude modal frequencies). requirement is a high level accuracy availability fixed solutions, which ensure reliable operation result precise estimation bridge's response. However, derived time series can be contaminated by noise, due performance satellite(s), geometry satellite constellation potential obstructions elements, even lead solution poor...

Monitoring surface deformation in real-time helps at planning and protecting infrastructures populations, manages sensitive production (i.e. SEVESO-type) mitigates long-term consequences of modifications implemented. We present RT-SHAKE, an algorithm developed to detect ground motions associated with landslides, subsurface collapses, subsidences, earthquakes or rock falls. RT-SHAKE detects first transient changes individual GPS time-series before investigating for spatial correlation(s)...

Implementation of Structural Health Monitoring systems on long-span bridges has become mandatory in many countries to ascertain the safety these structures and public, taking into account an increase usage threats due extreme loading conditions. However, successful delivery such a system is facing challenges including failure extract damage reliability information from monitoring data assist bridge operators with their maintenance planning activities. Supported by European Space Agency under...

Abstract The recent advances of low-cost GNSS receivers have broadened their application field not only in positioning and navigation, but also deformation monitoring civil engineering structures geohazards. Even though some consumer-grade can achieve cm-level accuracy, lower performance compared to the dual-frequency high-end restricts its systematic technology projects. In this study, noise level are assessed against geodetic terms precision availability when subjected different...

The 2008 June 8, moment magnitude MW 6.4 crustal earthquake in northwestern Peloponnese, Greece, was a strong-shaking dextral strike-slip event with teleseismic broad-band and high-frequency energy magnitudes Me of 6.8 7.2, respectively. A high stress drop 5–10 times the global average is associated excessive energy. NE–SW trending fault plane shown by aftershock distribution focal mechanism not previously mapped faults, no obvious coseismic surface rupture discovered. Contrasting enhanced...

Measurement of deflections certain bridges is usually hampered by corruption the GPS signal multipath associated with passing vehicles, resulting to unrealistically large apparent displacements. Field data from Gorgopotamos train bridge in Greece and systematic experiments revealed that such bias due superimposition two major effects, (i) changes geometry satellites because partial masking vehicles (this effect can be faced solutions excluding get temporarily blocked vehicles) (ii) dynamic...

We show that high-rate Global Positioning System (GPS) can have a vital role to play in near-real-time monitoring of potentially destructive earthquakes.We do this by investigating the potential GPS recording strong ground motions from earthquakes Switzerland and Japan.The study uses finite-fault stochastic groundmotion simulation based on Fourier amplitude spectra duration models previously developed for both countries, allowing comparisons terms timedomain characteristics (here, peak...

Continuous advancements in GNSS systems have led, apart from the broadly used GPS, to development of other satellite (Galileo, BeiDou, GLONASS), which significantly increased number available satellites for positioning applications. However, despite satellites’ redundancy, a potential poor signal (i.e., low signal-to-noise ratio) can negatively affect GNSS’s performance and accuracy. On hand, selecting high-quality signals by retaining sufficient enhance performance. Various methods,...

Permanent GNSS stations providing high-rate data have become a well-established practice, offering valuable insights into co-seismic displacement and seismic wave propagation during earthquakes. This study focuses on the displacements induced by doublet of earthquakes with magnitudes Mw 7.8 7.6 in south-eastern Turkey February 2023. 1Hz were analyzed to assess both transient deformation near far-field.The analysis includes 1 Hz from over 41 continuously operating located earthquake sequence...

GPS and strong-motion sensors are broadly used for the monitoring of structural health Earth surface motions, focusing on response structures, earthquake characterization rupture modeling. Several studies have shown consistency two data sets within at certain frequency (e.g., 0.03<f<0.2Hz). The compatibility Precise Point Positioning (PPP) was assessed by comparing their respective displacement waveforms several bands (f<0.4Hz). For this purpose, there records Mw9.0 Tohoku 2011 23 very close...