The geodetic monitoring of local displacements and deformations is often needed for civil engineering structures and natural phenomena like, for example, landslides. A local permanent GNSS (Global Navigation Satellite Systems) network can be installed: receiver positions in the interest area are estimated and monitored with respect to reference stations. Usually, GNSS geodetic receivers are adopted and provide results with accuracies at the millimeter level: however, they are very expensive and the initial cost and the risk of damage and loss can discourage this approach. In this paper the accuracy and the reliability of low-cost u-blox GNSS receivers are experimentally investigated for local monitoring. Two experiments are analyzed. In the first, a baseline (65 m long) between one geodetic reference receiver and one u-blox is continuously observed for one week: the data are processed by hourly sessions and the results provide comparisons between two processing packages and a preliminary accuracy assessment. Then, a network composed of one geodetic and two u-blox receivers is set up. One u-blox is installed on a device (slide) that allows to apply controlled displacements. The geodetic and the other u-blox (at about 130 m) act as references. The experiment lasts about two weeks. The data are again processed by hourly sessions. The estimated displacements of the u-blox on the slide are analyzed and compared with the imposed displacements. All of the results are encouraging: in the first experiment the standard deviations of the residuals are smaller than 5 mm both in the horizontal and vertical; in the second, they are slightly worse but still satisfactory (5 mm in the horizontal and 13 mm in vertical) and the imposed displacements are almost correctly identified.

The Global Positioning System (GPS) has been repeatedly proven to be a powerful tool to estimate coseismic displacements and waveforms, with accuracies ranging from few millimeters to few centimeters. These promising results were achieved following two main strategies: differential positioning (DP) and precise point positioning (PPP; Bock et al. [1993], Kouba [2003], Larson et al. [2007], Larson [2009], Ohta et al. [2012], Xu et al. [2012], and Hung and Rau [2013]). In particular, both the modeling of fault rupture and the seismic moment estimation could benefit from GPS‐derived displacements, because GPS is not...

This paper presents an experimental study on the integration of the fifth generation (5G) cellular networks and the Global Navigation Satellite System (GNSS) for positioning. Along with the use of experimental data collected from both 5G and GNSS deployed technologies, the novelty of this research includes the design of a Bayesian tracking methodology based on extended Kalman filtering for processing the 5G Time of Flights (TOFs) and jointly estimating the user position and the clock offsets of the 5G Base Stations (BSs), as well for their fusion with GNSS observations (both single and dual frequency). Data collection and experimental analyses are conducted in both static and mobile positioning scenarios. For standalone 5G positioning, we demonstrate the need of tracking the clock offsets of BSs, as they currently represent a primary impairment for precise positioning. In static conditions, we manage to reduce the positioning error from more than 100 m to approximately 5 m by jointly estimating these offsets and correct the TOFs accordingly, showcasing that the current 5G network is a possible alternative to single frequency code-only GNSS positioning. The 5G+GNSS hybrid solution is shown to guarantee a more reliable and accurate positioning as the two technologies mutually assist each other, particularly when single frequency GNSS processing is considered. On the other hand, when the GNSS receiver is able to perform dual frequency processing, location estimation does not benefit from the hybridization with 5G as GNSS is already highly accurate. Overall, the achieved results confirm the viability of 5G+GNSS integration from an experimental standpoint, showing the potentialities of the currently-deployed 5G network for positioning.

During May 2012, the CERN-CNGS neutrino beam has been operated for two weeks for a total of ~1.8 × 10¹⁷ p.o.t., with the proton beam made of bunches, few ns wide and separated by 100 ns. This beam structure allows a very accurate time of flight measurement of neutrinos from CERN to LNGS on an event-by-event basis. Both the ICARUS-T600 PMT-DAQ and the CERN-LNGS timing synchronization have been substantially improved for this campaign, taking advantage of additional independent GPS receivers, both at CERN and LNGS as well as of the deployment of the “White Rabbit” protocol both at CERN and LNGS. The ICARUS-T600 detector has collected 25 beam-associated events; the corresponding time of flight has been accurately evaluated, using all different time synchronization paths. The measured neutrino time of flight is compatible with the arrival of all events with speed equivalent to the one of light: the difference between the expected value based on the speed of light and the measured value is δt = tof c −tof ν = 0.10 ± 0.67_stat. ± 2.39_syst. ns. This result is in agreement with the value previously reported by the ICARUS Collaboration, δt = 0.3 ± 4.9_stat. ± 9.0_syst. ns, but with improved statistical and systematic accuracy.