scholarly journals Detection of Structural Vibration with High-Rate Precise Point Positioning: Case Study Results Based on 100 Hz Multi-GNSS Observables and Shake-Table Simulation

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 4832 ◽  
Author(s):  
Paziewski ◽  
Sieradzki ◽  
Baryla
Keyword(s):  
Precise Point Positioning ◽  
High Rate ◽  
Structural Vibration ◽  
Shake Table ◽  
Processing Strategy ◽  
Study Results ◽  
Designed Experiment ◽  
Point Positioning ◽  
The Difference ◽  
Set Up

This contribution presents and assesses the methodology aiming at the characterization of the structural vibrations with high-rate GNSS measurements. As commonly employed precise point positioning (PPP) based on ionosphere-free linear combination of undifferenced signals may not meet the high requirements in terms of displacement precision, a modified processing strategy has been proposed. The algorithms were implemented in the own-developed GNSS processing software and validated using the designed experiment. For this purpose, we have set up a field experiment taking advantage of the prototype shake-table, which simulated the dynamic horizontal displacements of the GNSS antenna. The device ensured a periodic motion of the antenna with modifiable characteristics, namely amplitude and frequency. In this experiment, we have set the amplitudes from 1.5 to 9 mm and the frequency to 3.80 Hz. As a dataset, we have used 100 Hz GPS, Galileo, and BDS measurements. The results confirmed a high applicability of the enhanced PPP processing strategy for precise displacement detection. Specifically, it was feasible to obtain the dynamic displacements with precision at the level of millimeters. The differences between the PPP-derived amplitude and the true amplitude of the simulated displacements were in the range of 0.5–1.3 mm, whereas the difference between the detected and benchmark frequency did not exceed 0.026 Hz. Hence, the proposed methodology allows meeting the specific demands of structural displacement monitoring.

High-rate GNSS Positioning for Precise Detection of Dynamic Displacements and Deformations: Methodology and Case Study Results

2017 ◽  
Author(s):  
Jacek Paziewski ◽  
Rafal Sieradzki ◽  
Radoslaw Baryla
Keyword(s):  
Precise Point Positioning ◽  
High Rate ◽  
Small Scale ◽  
Practical Reasons ◽  
High Temporal Resolution ◽  
Relative Positioning ◽  
Engineering Structures ◽  
Gnss Positioning ◽  
Study Results ◽  
Point Positioning

The monitoring of static and dynamic deformations of buildings and other engineering structures is of great interest for many scientific and practical reasons. Such measurements provide information required for safe maintenance of the constructions being a subject of various excitations. At present one of the most commonly used technology for this purpose is the high-rate GNSS positioning. The application of GNSS technology with appropriate processing methodology may meet the specific requirements which result in extraction of information on dynamic displacements and deformations of ground and engineering structures. The high temporal resolution and precision of GNSS phase observations predestine this technology to be applied to the most demanding applications in terms of accuracy, availability and reliability. In this study we present preliminary results of application of precise GNSS positioning for detection of small scale (centimeter level) dynamic displacements. In the first part of work there are described methodology and algorithms of precise coordinate estimation, involving both the relative positioning as well as the Precise Point Positioning technique. In the experiment both approaches were applied to monitor of antenna point variations on the basis of high-rate (20 Hz) observations processed in self-developed software. The dynamic displacements were simulated using specially constructed device moving GNSS antenna with dedicated amplitude and frequency. The obtained results indicate on possibility of detection of dynamic GNSS antenna displacements even at the level of millimetres using relative positioning. Moreover, the Precise Point Positioning approach has also proved its applicability to detect high-rate small scale changes of the controlled site coordinates.

scholarly journals Examining the Accuracy of Network RTK and Long Base RTK Methods with Repetitive Measurements

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Tamer Baybura ◽  
İbrahim Tiryakioğlu ◽  
Mehmet Ali Uğur ◽  
Halil İbrahim Solak ◽  
Şeyma Şafak
Keyword(s):  
Real Time ◽  
Precise Point Positioning ◽  
High Accuracy ◽  
Base Station ◽  
Network Rtk ◽  
Real Time Kinematic ◽  
Study Results ◽  
Point Positioning

Real-time kinematic (RTK) technique is important for mapping applications requiring short measure time, the distance between rover and base station, and high accuracy. There are several RTK methods used today such as the traditional RTK, long base RTK (LBRTK), network RTK (NRTK), and precise point positioning RTK (PPP-RTK). NRTK and LBRTK are popular with the advantage of the distance, the time, and accuracy. In the present study, the NRTK and LBRTK measurements were compared in terms of accuracy and distance in a test network with 6 sites that was established between 5 and 60 km. Repetitive NRTK and LBRTK measurements were performed on 6 different days in 2015-2017-2018 and additionally 4 campaigns of repetitive static measurements were carried out in this test network. The results of NRTK and LBRTK methods were examined and compared with all relevant aspects by considering the results of the static measurements as real coordinates. The study results showed that the LBRTK and NRTK methods yielded similar results at base lengths up to 40 km with the differences less than 3 cm horizontally and 4 cm vertically.

Multipath extraction and mitigation for high-rate multi-GNSS precise point positioning

2019 ◽  
Vol 93 (10) ◽  
pp. 2037-2051 ◽  
Author(s):  
Kai Zheng ◽  
Xiaohong Zhang ◽  
Pan Li ◽  
Xingxing Li ◽  
Maorong Ge ◽  
...  
Keyword(s):  
Precise Point Positioning ◽  
High Rate ◽  
Point Positioning

scholarly journals The Impact of Different Ocean Tide Loading Models on GNSS Estimated Zenith Tropospheric Delay Using Precise Point Positioning Technique

2020 ◽  
Vol 12 (18) ◽  
pp. 3080
Author(s):  
Jinglei Zhang ◽  
Xiaoming Wang ◽  
Zishen Li ◽  
Shuhui Li ◽  
Cong Qiu ◽  
...  
Keyword(s):  
Precise Point Positioning ◽  
Precipitable Water ◽  
Global Navigation Satellite Systems ◽  
Ocean Tide ◽  
Tropospheric Delay ◽  
Ocean Tide Loading ◽  
Zenith Tropospheric Delay ◽  
Point Positioning ◽  
The Difference ◽  
The Impact

Global navigation satellite systems (GNSSs) have become an important tool to derive atmospheric products, such as the total zenith tropospheric delay (ZTD) and precipitable water vapor (PWV) for weather and climate studies. The ocean tide loading (OTL) effect is one of the primary errors that affects the accuracy of GNSS-derived ZTD/PWV, which means the study and choice of the OTL model is an important issue for high-accuracy ZTD estimation. In this study, GNSS data from 1 January 2019 to 31 January 2019 are processed using precise point positioning (PPP) at globally distributed stations. The performance of seven widely used global OTL models is assessed and their impact on the GNSS-derived ZTD is investigated by comparing them against the ZTD calculated from co-located radiosonde observations. The results indicate that the inclusion or exclusion of the OTL effect will lead to a difference in ZTD of up to 3–15 mm for island stations, and up to 1–2 mm for inland stations. The difference of the ZTD determined with different OTL models is quite small, with a root-mean-square (RMS) value below 1.5 mm at most stations. The comparison between the GNSS-derived ZTD and the radiosonde-derived ZTD indicates that the adoption of OTL models can improve the accuracy of GNSS-derived ZTD. The results also indicate that the adoption of a smaller cutoff elevation, e.g., 3° or 7°, can significantly reduce the difference between the ZTDs determined by GNSS and radiosonde, when compared against a 15° cutoff elevation. Compared to the radiosonde-derived ZTD, the RMS error of GNSS-derived ZTD is approximately 25–35 mm at a cutoff elevation of 15°, and 15–25 mm when the cutoff elevation is set to 3°.

scholarly journals Regiomontan: A Regional High Precision Ionosphere Delay Model and Its Application in Precise Point Positioning

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2845
Author(s):  
Janina Boisits ◽  
Marcus Glaner ◽  
Robert Weber
Keyword(s):  
Precise Point Positioning ◽  
Ionospheric Delay ◽  
Single Frequency ◽  
External Information ◽  
Delay Model ◽  
Dual Frequency ◽  
Propagation Delays ◽  
Point Positioning ◽  
The Difference ◽  
High Level

Propagation delays of GNSS signals caused by the ionosphere can range up to several meters in zenith direction and need to be corrected. Geodetic receivers observing at two or more frequencies allow the mitigation of the ionospheric effects by forming linear combinations. However, single frequency users depend on external information. The ionosphere delay model Regiomontan developed at TU Wien is a regional ionospheric delay model providing high accuracy information with a latency of only a few hours. The model is based on dual-frequency phase observations of a regional network operated by EPOSA (Echtzeit Positionierung Austria) and partners. The corrections cover a geographical extent for receiver positions within Austria and are provided in the standardized IONEX format. The performance of Regiomontan as well as its application in Precise Point Positioning (PPP) were tested with our in-house PPP software raPPPid using the so-called uncombined model with ionospheric constraint. Various tests, e.g., analyzing the coordinate convergence behavior or the difference between estimated and modeled ionospheric delay, proving the high level of accuracy provided with Regiomontan. We conclude that Regiomontan performs at a similar level of accuracy as IGS final TEC maps, but with explicitly reduced latency.

scholarly journals A Smart Realtime Service to Broadcast the Precise Orbits of GPS Satellite and Its Performance on Precise Point Positioning

Sensors ◽  
2020 ◽  
Vol 20 (11) ◽  
pp. 3276
Author(s):  
Dehai Li ◽  
Wei Yan ◽  
Jinzhong Mi ◽  
Yamin Dang ◽  
Yunbin Yuan ◽  
...  
Keyword(s):  
Real Time ◽  
Data Stream ◽  
Precise Point Positioning ◽  
Rapid Development ◽  
Relative Distance ◽  
Satellite Orbits ◽  
Gps Navigation ◽  
Point Positioning ◽  
The Difference ◽  
First Time

At present, Global Position System (GPS) navigation ephemeris mainly broadcasts satellite orbits with meter-level precision for standard point positioning and precise relative positioning. With the rapid development of real-time precise point positioning (PPP), the receiver or smartphone has begun to demand more and more convenient, continuous, and reliable access to real-time services of precise orbits. Therefore, this study proposes a solution of utilizing the 18-parameter ephemeris to directly broadcast ultra-rapid precise predicted orbits with centimeter-level precision for real-time PPP. For the first time in GPS, the difference in the PPP results between the precise orbits and the calculated orbits broadcasted from the generated ephemeris parameters is supplied as follows: (1) During the validity period of 2 h, root mean square (RMS) of the relative distance offsets between the results of PPP with the precise orbits and the results of PPP the 18-parameter ephemeris is only 0.0098 m. (2) Within 15 min after the validity period of 2 h, RMS of the relative distance offsets between the results of PPP with the precise orbits and the results of PPP with the predicted orbits by 18-parameter ephemeris is only 0.0057 m. Consequently, the 18-parameter ephemeris is feasible and advisable to broadcast precise predicted orbits for real-time PPP applications. Compared with the classic precise orbits broadcast mode with the orbit corrections defined by the radio technical commission for maritime services standards 10403.2 (RTCM), the mode of broadcasting the precise orbits with the 18-parameter ephemeris achieved the following improvements in convenience, continuity, and reliability: (1) The calculation of satellite position is the same as that of the navigation ephemeris excluding the additional correction operations required to the RTCM; (2) the amount of broadcast parameters was reduced by 20 times; (3) the length of the validity period was expanded 120 times, where the longer valid period helped to overcome the orbit corrections loss caused by RTCM stream failures; and (4) within 15 min after the validity period, the predicted orbits with an accuracy of 2 cm could still be provided by the 18-parameter ephemeris, which can ensure the real-time services of precise orbits in the case of a 15 min communication interruption of the RTCM orbit correction data stream.

scholarly journals BDS Precise Point Positioning for Seismic Displacements Monitoring: Benefit from the High-Rate Satellite Clock Corrections

Sensors ◽  
2016 ◽  
Vol 16 (12) ◽  
pp. 2192 ◽  
Author(s):  
Tao Geng ◽  
Xing Su ◽  
Rongxin Fang ◽  
Xin Xie ◽  
Qile Zhao ◽  
...  
Keyword(s):  
Precise Point Positioning ◽  
High Rate ◽  
Satellite Clock ◽  
Point Positioning ◽  
Seismic Displacements
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