ITRF use for global applications and estimation of linear velocities of dense networks

2020 ◽  
Author(s):  
Francesco Matonti ◽  
Adam Miller ◽  
Nejc Krasovec
Keyword(s):  
Reference Frame ◽  
Reference Station ◽  
Dense Networks ◽  
Long Term Stability ◽  
Station Coordinates ◽  
Increasing Demand ◽  
Daily Solution ◽  
Gnss Network ◽  
Gnss Networks

<p>GNSS networks are required to continue meeting the ever-increasing demand for global positioning applications operating in a global reference frame. Meanwhile, the requirements of applications based in a local (regional) official reference frame must still be met. Using Bernese GNSS software (Dach, 2015), we can process GNSS networks in the ITRF2014 reference frame and, using Leica GNSS Spider, deliver GNSS corrections in ITRF2014, whilst continuing to serve those with local demands.  To maintain high precision of the GNSS network we perform a daily solution, which is computed based on precise orbits and following the guidelines of the EPN Analysis Centres. To ensure the daily solution runs with correct data, we maintain a database of all reference station equipment changes. Using the daily solution, we are estimating the linear velocity of reference stations within GNSS networks, and are also considering jumps due to equipment changes. The estimated velocities give the opportunity to monitor the long-term stability of the network as well as the quality of reference station coordinates. The daily solution and monitoring of GNSS networks are executed by the Leica Geosystems solution named Leica CrossCheck, which is based on Bernese GNSS software. Leica CrossCheck is capable to monitor GNSS networks of all scales. This includes the computation and monitoring of approximately 5000 GNSS reference stations worldwide, including those part of the HxGN SmartNet GNSS network.  </p><p>KEYWORDS: GNSS reference station network, Bernese GNSS 5.2, Leica CrossCheck, Leica GNSS Spider, HxGN SmartNet <br> </p><p>References: <br>Dach, R., S. Lutz, P. Walser, P. Fridez (Eds); 2015: Bernese GNSS Software Version 5.2. User manual, Astronomical Institute, Universtiy of Bern, Bern Open Publishing. DOI: 10.7892/boris.72297; ISBN: 978-3-906813-05-9.   <br> </p>

scholarly journals Regional integration of long-term national dense GNSS network solutions

GPS Solutions ◽  
2019 ◽  
Vol 23 (4) ◽  
Author(s):  
Ambrus Kenyeres ◽  
J. G. Bellet ◽  
C. Bruyninx ◽  
A. Caporali ◽  
F. de Doncker ◽  
...  
Keyword(s):  
Regional Integration ◽  
Reference Frames ◽  
Collaborative Effort ◽  
High Quality ◽  
Combined Solution ◽  
Gnss Network ◽  
Constraint Approach ◽  
Gnss Networks

Abstract The EUREF Permanent Network Densification is a collaborative effort of 26 European GNSS analysis centers providing series of daily or weekly station position estimates of dense national and regional GNSS networks, in order to combine them into one homogenized set of station positions and velocities. During the combination, the station meta-data, including station names, DOMES numbers, and position offset definitions were carefully homogenized, position outliers were efficiently eliminated, and the results were cross-checked for any remaining inconsistencies. The results cover the period from March 1999 to January 2017 (GPS week 1000-1933) and include 31 networks with positions and velocities for 3192 stations, well covering Europe. The positions and velocities are expressed in ITRF2014 and ETRF2014 reference frames based on the Minimum Constraint approach using a selected set of ITRF2014 reference stations. The position alignment with the ITRF2014 is at the level of 1.5, 1.2, and 3.2 mm RMS for the East, North, Up components, respectively, while the velocity RMS values are 0.17, 0.14, and 0.38 mm/year for the East, North, and Up components, respectively. The high quality of the combined solution is also reflected by the 1.1, 1.1, and 3.5 mm weighted RMS values for the East, North, and Up components, respectively.

scholarly journals Verification of the Polish Geodetic Reference Frame by Means of a New Solution Based on Permanent GNSS Data from the Years 2011-2014

2016 ◽  
Vol 102 (1) ◽  
pp. 52-66 ◽  
Author(s):  
T. Liwosz ◽  
M. Ryczywolski
Keyword(s):  
Reference Frame ◽  
Primary Network ◽  
Position Time Series ◽  
Gnss Network ◽  
Gnss Data ◽  
Geodetic Reference Frame ◽  
Minimum Constraints ◽  
Data Length ◽  
Good Agreement

Abstract The new solution for the Polish geodetic primary GNSS network was created to verify the currently used reference frame (PL-ETRF2000). The new solution is based on more GNSS data (more daily observation sessions included, a longer data timespan, GLONASS observations added) which were processed in a newer reference frame (IGb08) according to up-to-date methodology and using the latest version of Bernese GNSS Software. The new long-term solution (spanning 3.7 years) was aligned to the IGb08 reference frame using a minimum constraints approach. We categorized Polish reference stations into two categories according to their data length. We obtained good agreement of the new solution with the PL-ETRF2000: for most stations position differences did not exceed 5 mm in horizontal, and 10 mm in vertical components. However, for 30 stations we observed discontinuities in position time series, mostly due to GNSS equipment changes, which occured after the introduction of PL-ETRF2000. Position changes due to the discontinuities reached 9.1 mm in horizontal components, and 26.9 mm in vertical components. The new solution takes into account position discontinuities, and in addition also includes six new stations which were installed after the introduction of the PL-ETRF2000. Therefore, we propose to update the currently-used reference frame for the Polish geodetic primary network (PL-ETRF2000) with the new solution. The new solution was also accepted by the EUREF Technical Working Group as a class A solution (highest accuracy) according to EUREF standards.

Long-term stability of the terrestrial reference frame

2005 ◽  
Vol 36 (3) ◽  
pp. 342-349 ◽  
Author(s):  
Z. Altamimi ◽  
C. Boucher ◽  
D. Gambis
Keyword(s):  
Reference Frame ◽  
Terrestrial Reference Frame ◽  
Term Stability ◽  
Long Term Stability

scholarly journals Results of GPS reprocessing campaign (1996-2011) provided by Geodetic observatory Pecný

2012 ◽  
Vol 9 ◽  
pp. 77-90 ◽  
Author(s):  
Jan Douša ◽  
Pavel Václavovic
Keyword(s):  
Time Series ◽  
Reference Frame ◽  
Historical Development ◽  
Vertical Component ◽  
Close Relation ◽  
The North ◽  
Station Coordinates ◽  
Definition Of ◽  
Global Reference Frame

The paper presents the GOP first reprocessing results, which officially contributed to the EPN-repro1 project. It also describes the 15-year GOP cumulative solution providing station coordinates, velocities and their discontinuities over the period of 1996-2011. Repeatabilities estimated from cleaned long-term coordinate time-series reached 1-2 mm and 4-6 mm in horizontal and vertical component, respectively. We then showed the exploitation of GOP reprocessing results in the assessment of the EUREF ITRF2005 densification and the latest ITRS realization, ITRF2008. We identified and confirmed the North-South tilt (≈ 2mas) in the currently available European reference frame based on the EPN cumulative solution updated in GPS week 1600. The study showed a historical development of the tilt and its close relation to a weak velocity datum definition of this realization, which is very important for a long-term datum prediction. Selected EPN station coordinates, velocities and discontinuities of the latest ITRS realization (ITRF2008) were also assessed. Specific problems for some EPN stations were identified in the global reference frame. This emphasized further necessity to check all the stations before their use for datum definition for regional densifications.

scholarly journals A Simple, Extremely Stable Single-Tube Liquid Scintillation System for Radiocarbon Dating

Radiocarbon ◽  
2005 ◽  
Vol 47 (1) ◽  
pp. 89-97 ◽  
Author(s):  
Pall Theodórsson
Keyword(s):  
Radiocarbon Dating ◽  
Liquid Scintillation ◽  
Correction Method ◽  
Counting Efficiency ◽  
Background Count ◽  
Background Count Rate ◽  
Long Term Stability ◽  
Increasing Demand ◽  
Better Than

This paper describes a simple and compact liquid scintillation radiocarbon dating system, ICELS, and demonstrates its long-term stability and reproducibility to a precision level rarely presented before, better than 0.04% (3 14C yr). Inexpensive systems of this kind may, in the future, help to meet increasing demand for high precision (±16 to ±20 14C yr) and strict quality control. ICELS comprises a compact detector unit, where a 3-mL dome-shaped vial, with an optimal light reflector, sits on the top of a vertical 30-mm photomultiplier tube. Sample changing is manual. The high voltage is set at the balance point for each sample, securing maximal counting stability. The quench correction method used (spectrum restoration) corrects with 0.04% precision for all parameters that can normally shift the 14C spectrum. For 3 mL of benzene at 71% 14C counting efficiency (recent carbon 23 cpm), the background is 1.72 cpm behind a 5-cm-thick shield of lead (27 kg) and 1.53 cpm behind 10 cm of lead. The background count rate corrected for atmospheric pressure variations was completely stable over 47- and 57-d testing periods for the 2 systems.

On the long-term stability of terrestrial reference frame solutions based on Kalman filtering

2018 ◽  
Vol 92 (9) ◽  
pp. 1063-1077 ◽  
Author(s):  
Benedikt Soja ◽  
Richard S. Gross ◽  
Claudio Abbondanza ◽  
Toshio M. Chin ◽  
Michael B. Heflin ◽  
...  
Keyword(s):  
Reference Frame ◽  
Kalman Filtering ◽  
Terrestrial Reference Frame ◽  
Term Stability ◽  
Long Term Stability

scholarly journals Influence of different Ni coatings on the long-term behavior of ultrasonic welded EN AW 1370 cable/EN CW 004A arrestor dissimilar joints

2020 ◽  
Author(s):  
Tobias Köhler ◽  
Michael Grätzel ◽  
Jean Pierre Bergmann
Keyword(s):  
Power Systems ◽  
Stress Tests ◽  
Dissimilar Joints ◽  
Long Term Stability ◽  
Nickel Coatings ◽  
Standards And Regulations ◽  
Increasing Demand ◽  
The One ◽  
Long Term Behavior

AbstractThe increasing demand for energy-efficient vehicles requires suitable methods for cost and weight reduction. This can be achieved by the replacement of copper by aluminum, in particular for the on-board power systems. However, the complete substitution is restricted by the mechanical and physical material properties of aluminum as well as challenges in the aluminum copper interface. The challenges concern the corrosion vulnerability and the occurrence of brittle intermetallic compounds (IMC) which can negatively influence the mechanical properties and the electrical conductivity. Therefore, current investigations focus on the one hand on the realization of dissimilar aluminum copper joints by suitable joining technologies, like ultrasonic welding, and on the other hand on the assurance of a sufficient prevention against harmful corrosion effects. In cases where the joint cannot be protected against corrosion by sealing, nickel coatings can be used to protect the joint. In the present study, the influence of electroless, electroplated, and sulfamate nickel coatings was investigated regarding the long-term stability. The joints were performed as industry-related arrester connections, consisting of EN AW 1370 cables and EN CW 004A terminals. The samples were exposed to corrosive as well as electrical, thermal, and mechanical stress tests according to current standards and regulations.

Stability and Change in Emotional Intelligence: Exploring the Transition to Young Adulthood

2005 ◽  
Vol 26 (2) ◽  
pp. 100-106 ◽  
Author(s):  
James D.A. Parker ◽  
Donald H. Saklofske ◽  
Laura M. Wood ◽  
Jennifer M. Eastabrook ◽  
Robyn N. Taylor
Keyword(s):  
High School ◽  
Emotional Intelligence ◽  
Postsecondary Education ◽  
Life Transition ◽  
Full Time ◽  
Major Life ◽  
Long Term Stability ◽  
Time Period ◽  
Transition From High School

Abstract. The concept of emotional intelligence (EI) has attracted growing interest from researchers working in various fields. The present study examined the long-term stability (32 months) of EI-related abilities over the course of a major life transition (the transition from high school to university). During the first week of full-time study, a large group of undergraduates completed the EQ-i:Short; 32 months later a random subset of these students (N = 238), who had started their postsecondary education within 24 months of graduating from high school, completed the measures for a second time. The study found EI scores to be relatively stable over the 32-month time period. EI scores were also found to be significantly higher at Time 2; the overall pattern of change in EI-levels was more than can be attributed to the increased age of the participants.

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