Article
Geochemistry & Geophysics
Christopher Kotsakis, Miltiadis Chatzinikos
Summary: The paper investigates the inference problem of frame accuracy at coordinate system level and discusses the practical impact on the results. A relevant case study is performed to evaluate the accuracy of the origin, orientation, and scale in the ITRF frame series.
JOURNAL OF GEODESY
(2023)
Article
Geochemistry & Geophysics
Oliver Montenbruck, Peter Steigenberger, Arturo Villiger, Paul Rebischung
Summary: Phase center offsets of GNSS transmit antennas affect the scale of the terrestrial reference frame, and changes in the reference frame scale require corrections to the antenna offsets. A semi-analytical model is developed to determine the relation between the offsets and scale for different GNSSs.
JOURNAL OF GEODESY
(2022)
Article
Geochemistry & Geophysics
P. J. Johnston, M. S. Filmer, T. Fuhrmann
Summary: The study investigates the process of connecting to a terrestrial reference frame (TRF) using different methods and compares the applicability of three connection methods. Results suggest that selecting the optimal TRF connection method depends on local conditions, CORS network geometry, and deformation field characteristics. Different methods may result in significantly different deformation rate changes.
JOURNAL OF GEODESY
(2021)
Article
Geochemistry & Geophysics
Arnaud Pollet, David Coulot, Richard Biancale, Felix Perosanz, Sylvain Loyer, Jean-Charles Marty, Susanne Glaser, Vladimir Schott-Guilmault, Jean-Michel Lemoine, Flavien Mercier, Samuel Nahmani, Mioara Mandea
Summary: The geoscience community set a goal of 1 mm accuracy and 0.1 mm/yr stability for the terrestrial reference frame (TRF) realization in 2009. However, the last International Terrestrial Reference Frame has not yet reached this target. To achieve this goal, the use of multi-technique satellites as space-ties has been studied since 2011 and proposals have been made in response to different space agency calls.
JOURNAL OF GEODESY
(2023)
Article
Engineering, Aerospace
Patrick Schreiner, Rolf Koenig, Karl Hans Neumayer, Anton Reinhold
Summary: The Helmholtz-Zentrum Potsdam GFZ German Research Centre for Geosciences is involved in the reprocessing of satellite data to improve the accuracy of global positioning systems. By combining multiple observation techniques, they were able to determine the reference frame for satellite orbits and evaluate the precision of the measurements. The results showed that using GPS in combination with other techniques significantly improved the accuracy of the orbits, particularly in the transverse and normal directions.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Multidisciplinary Sciences
Marlee A. Tucker, Aafke M. Schipper, Tempe S. F. Adams, Nina Attias, Tal Avgar, Natarsha L. Babic, Kristin J. Barker, Guillaume Bastille-Rousseau, Dominik M. Behr, Jerrold L. Belant, Dean E. Beyer, Niels Blaum, J. David Blount, Dirk Bockmuhl, Ricardo Luiz Pires Boulhosa, Michael B. Brown, Bayarbaatar Buuveibaatar, Francesca Cagnacci, Justin M. Calabrese, Rok Cerne, Simon Chamaille-Jammes, Aung Nyein Chan, Michael J. Chase, Yannick Chaval, Yvette Chenaux-Ibrahim, Seth G. Cherry, Dusko Cirovic, Emrah Coban, Eric K. Cole, Laura Conlee, Alyson Courtemanch, Gabriele Cozzi, Sarah C. Davidson, Darren DeBloois, Nandintsetseg Dejid, Vickie DeNicola, Arnaud L. J. Desbiez, Iain Douglas-Hamilton, David Drake, Michael Egan, Jasper A. J. Eikelboom, William F. Fagan, Morgan J. Farmer, Julian Fennessy, Shannon P. Finnegan, Christen H. Fleming, Bonnie Fournier, Nicholas L. Fowler, Mariela G. Gantchoff, Alexandre Garnier, Benedikt Gehr, Chris Geremia, Jacob R. Goheen, Morgan L. Hauptfleisch, Mark Hebblewhite, Morten Heim, Anne G. Hertel, Marco Heurich, A. J. Mark Hewison, James Hodson, Nicholas Hoffman, J. Grant C. Hopcraft, Djuro Huber, Edmund J. Isaac, Karolina Janik, Milos Jezek, Orjan Johansson, Neil R. Jordan, Petra Kaczensky, Douglas N. Kamaru, Matthew J. Kauffman, Todd M. Kautz, Roland Kays, Allicia P. Kelly, Jonas Kindberg, Miha Krofel, Josip Kusak, Clayton T. Lamb, Tayler N. LaSharr, Peter Leimgruber, Horst Leitner, Michael Lierz, John D. C. Linnell, Purevjav Lkhagvaja, Ryan A. Long, Jose Vicente Lopez-Bao, Matthias-Claudio Loretto, Pascal Marchand, Hans Martin, Lindsay A. Martinez, Roy T. McBride, Ashley A. D. McLaren, Erling Meisingset, Joerg Melzheimer, Evelyn H. Merrill, Arthur D. Middleton, Kevin L. Monteith, Seth A. Moore, Bram Van Moorter, Nicolas Morellet, Thomas Morrison, Rebekka Mueller, Atle Mysterud, Michael J. Noonan, David O'Connor, Daniel Olson, Kirk A. Olson, Anna C. Ortega, Federico Ossi, Manuela Panzacchi, Robert Patchett, Brent R. Patterson, Rogerio Cunha de Paula, John Payne, Wibke Peters, Tyler R. Petroelje, Benjamin J. Pitcher, Bostjan Pokorny, Kim Poole, Hubert Potocnik, Marie-Pier Poulin, Robert M. Pringle, Herbert H. T. Prins, Nathan Ranc, Slaven Reljic, Benjamin Robb, Ralf Roder, Christer M. Rolandsen, Christian Rutz, Albert R. Salemgareyev, Gustaf Samelius, Heather Sayine-Crawford, Sarah Schooler, Cagan H. Sekercioglu, Nuria Selva, Paola Semenzato, Agnieszka Sergiel, Koustubh Sharma, Avery L. Shawler, Johannes Signer, Vaclav Silovsky, Joao Paulo Silva, Richard Simon, Rachel A. Smiley, Douglas W. Smith, Erling J. Solberg, Diego Ellis-Soto, Orr Spiegel, Jared Stabach, Jenna Stacy-Dawes, Daniel R. Stahler, John Stephenson, Cheyenne Stewart, Olav Strand, Peter Sunde, Nathan J. Svoboda, Jonathan Swart, Jeffrey J. Thompson, Katrina L. Toal, Kenneth Uiseb, Meredith C. VanAcker, Marianela Velilla, Tana L. Verzuh, Bettina Wachter, Brittany L. Wagler, Jesse Whittington, Martin Wikelski, Christopher C. Wilmers, George Wittemyer, Julie K. Young, Filip Zieba, Tomasz Zwijacz-Kozica, Mark A. J. Huijbregts, Thomas Mueller
Summary: COVID-19 lockdowns have had significant impacts on wildlife, altering their spatial behaviors such as increased movements and reduced avoidance of roads. However, individual responses varied and were influenced by the different lockdown conditions.
Article
Engineering, Electrical & Electronic
Hao Dong, Cunqing Hua, Lingya Liu, Wenchao Xu, Rahim Tafazolli
Summary: In this paper, we investigate the application of Intelligent Reflecting Surface (IRS) technology in an Integrated Terrestrial-Satellite Network (ITSN), aiming to maximize the weighted sum rate (WSR) by jointly optimizing transmit beamforming vectors, phase shift matrix, and user scheduling. Efficient algorithms are proposed for phase shift optimization, and simulation results show the performance gain of our schemes over benchmark ones.
IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS
(2023)
Article
Astronomy & Astrophysics
H. Krasna, L. Baldreich, J. Bohm, S. Boehm, J. Gruber, A. Hellerschmied, F. Jaron, L. Kern, D. Mayer, A. Nothnagel, O. Panzenbock, H. Wolf
Summary: This article introduces the computation of global reference frames from VLBI observations at the Vienna International VLBI Service for Geodesy and Astrometry (IVS) Analysis Center. The results include high-quality celestial and terrestrial reference frames, with improved positions of radio sources and the inclusion of new sources and newly established VLBI telescopes.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Environmental Sciences
Wenhao Li, Jintao Lei, C. K. Shum, Fei Li, Shengkai Zhang, Chanfang Shu, Wei Chen
Summary: This study examines the contributions of snowfall, rainfall, and runoff to the seasonal and transient crustal deformations of Greenland over the past two decades. The largest vertical displacement caused by precipitation occurs in southeastern Greenland, while the largest surface displacement caused by runoff is in western Greenland. The ice mass gain/loss in Greenland is correlated with latitude and temperature, with greater variations in the south and a clear transient deformation signal in terms of abrupt subsidence in 2010 followed by uplift in 2014.
REMOTE SENSING OF ENVIRONMENT
(2023)
Letter
Geosciences, Multidisciplinary
M. Lazecky, A. J. Hooper, P. Piromthong
Summary: Interferometric Synthetic Aperture Radar is used to measure deformation rates over continents, and the resulting measurements are relative due to unknown integer ambiguities caused by atmospheric signal propagation. However, by using spectral diversity, these ambiguities can largely cancel out, allowing measurements to be made with respect to a global reference frame. By combining data from different orbits, accurate absolute measurements of horizontal ground movement can be obtained, which are useful for global velocity and strain rate estimation.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
E. Harris, L. Yu, Y-P. Wang, J. Mohn, S. Henne, E. Bai, M. Barthel, M. Bauters, P. Boeckx, C. Dorich, M. Farrell, P. B. Krummel, Z. M. Loh, M. Reichstein, J. Six, M. Steinbacher, N. S. Wells, M. Bahn, P. Rayner
Summary: Anthropogenic nitrogen inputs have significant negative impacts on the environment, especially through the emission of the important greenhouse gas N2O. The shifts in terrestrial nitrogen loss pathways driven by global change are highly uncertain. This study presents a model that quantifies terrestrial nitrogen losses and N2O emission factors, revealing that atmospheric deposition inputs are the main cause of anthropogenic N2O emissions from soils. The predicted increase in fertilizer use in emerging economies will further accelerate N2O-driven climate warming, unless targeted mitigation measures are implemented.
NATURE COMMUNICATIONS
(2022)
Article
Environmental Sciences
Alessandra Tiberia, Alessandra Mascitelli, Leo Pio D'Adderio, Stefano Federico, Martino Marisaldi, Federico Porcu, Eugenio Realini, Andrea Gatti, Alessandro Ursi, Fabio Fuschino, Marco Tavani, Stefano Dietrich
Summary: This study conducted the first investigation of atmospheric conditions around terrestrial gamma-ray flash (TGF) occurrences over time using GPS sensors, geostationary satellite observations, and ERA5 reanalysis data. The research revealed a recurring pattern of increased water vapor two hours prior to TGF events, associated with lightning activity. The findings suggest the strong potential of utilizing GPS data to characterize the troposphere and improve our understanding of TGF production.
Article
Chemistry, Physical
Zhibing Zhou, Jiechao Cui, Qing Hou, Kun Zhang
Summary: In this paper, the morphological change of a silicon surface under continuous bombardment with 30-eV argon was studied using the molecular dynamics method. The atomic-scale dynamics processes of ripple formation and propagation were discussed in detail. The study revealed the relationship between the migration rate of surface atoms and the smooth-to-unstable mode transition of the silicon surface, as well as the propagation velocities of low-energy ion-induced ripples at different incidence angles.
APPLIED SURFACE SCIENCE
(2022)
Article
Optics
Jian-Rong Zhu, Rong Wang, Chun-Mei Zhang
Summary: This paper proposes an improved method for reference-frame-independent quantum key distribution (RFI-QKD) by introducing a new statistical quantity R to enhance performance and provide an estimation bound for the eavesdropper's knowledge. Simulation results show significant improvement in practical scenarios and also in the measurement-device-independent QKD (RFI-MDI-QKD) protocol.
Article
Environmental Sciences
Shize Song, Zhongkai Zhang, Guangli Wang
Summary: This paper reviews several commonly used constraints, summarizes their similarities and differences based on observation equations and normal equations, and discusses in detail the influence of internal constraints on the scale of VLBI long-term solutions.
Article
Engineering, Multidisciplinary
Peter Steigenberger, Oliver Montenbruck
Article
Engineering, Aerospace
Peter Steigenberger, Steffen Thoelert, Oliver Montenbruck
ADVANCES IN SPACE RESEARCH
(2020)
Article
Engineering, Aerospace
Oliver Montenbruck, Peter Steigenberger, Moritz Aicher
Summary: GNSS positioning relies on predicted orbit and clock information transmitted by satellites. A tailored force model for numerical orbit propagation has been proposed for high accuracy in real-time environments. Using the Galileo constellation as an example, global average signal-in-space range errors and 3D position errors are demonstrated to be small after two-week predictions, showing the capability for rapid first fix or contingency navigation without ground updates.
NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION
(2021)
Article
Remote Sensing
Peter Steigenberger, Oliver Montenbruck, Markus Bradke, Markus Ramatschi, Uwe Hessels
Summary: This paragraph describes the earth rotation parameters in modern navigation messages and how global navigation satellite systems obtain and use these parameters. The data shows some differences between different systems, but for spacecraft navigation, the broadcast ERP accuracy of GPS, QZSS, and IRNSS is sufficient to support autonomous navigation.
Article
Remote Sensing
Andre Hauschild, Oliver Montenbruck, Peter Steigenberger, Ilaria Martini, Ignacio Fernandez-Hernandez
Summary: The High Accuracy Service (HAS) is a new addition to the Galileo service portfolio that provides free correction data for precise point positioning in real-time. Through testing with the Sentinel-6A LEO satellite, it has been found that using HAS corrections can significantly improve positioning accuracy.
Article
Remote Sensing
Radoslaw Zajdel, Peter Steigenberger, Oliver Montenbruck
Summary: Since the release of phase center calibrations, the BeiDou Navigation Satellite System (BDS) has the potential to contribute to the terrestrial reference frame scale. This study evaluates the potential usage of the BDS-3 Medium Earth Orbit (MEO) constellation for defining the terrestrial reference frame scale. Different frequency pairs were investigated to determine if they result in different definitions of the terrestrial reference frame scale.
Article
Geochemistry & Geophysics
Oliver Montenbruck, Peter Steigenberger, Arturo Villiger, Paul Rebischung
Summary: Phase center offsets of GNSS transmit antennas affect the scale of the terrestrial reference frame, and changes in the reference frame scale require corrections to the antenna offsets. A semi-analytical model is developed to determine the relation between the offsets and scale for different GNSSs.
JOURNAL OF GEODESY
(2022)
Article
Remote Sensing
O. Montenbruck, P. Steigenberger, J. M. Sleewaegen
Summary: The study evaluates the pilot channel biases for different modern signals of GPS, Galileo, BeiDou-3, and QZSS constellations. The results show that the biases range from about 2ns for GPS L5 signal to less than 0.1-0.3ns for Galileo E1 and E5a/b signals. These findings are expected to improve the generation of satellite clock and bias products by the International GNSS Service and enable consistent use by multi-GNSS users.
Article
Remote Sensing
J. M. Sleewaegen, O. Montenbruck, P. Steigenberger
Summary: The analysis of the bias between QZSS L5-Q and L5-I pseudoranges reveals decimeter-level variations over the satellite passes, which is not observed in any other GNSS signal. The study shows that the bias depends on the orientation of the line-of-sight vector with respect to the transmit antenna panel of the QZSS satellite and its amplitude is satellite dependent. The cause of the bias is identified as interference from the L5S signal transmitted by QZSS satellites at the same frequency, introducing a distortion that affects pseudoranges produced using the pilot signal component.
Article
Geochemistry & Geophysics
P. Steigenberger, O. Montenbruck
Summary: Information on satellite antenna phase center offsets (PCOs) is crucial for high-precision applications of global navigation satellite systems. Pre-flight manufacturer calibrations of the PCOs are available for all individual Galileo satellites and each frequency. The consistency of the PCO values for different frequencies becomes increasingly important due to the growing number of E5b and E6-capable receivers and upcoming multi-frequency applications.
JOURNAL OF GEODESY
(2023)
Article
Geochemistry & Geophysics
Bingbing Duan, Urs Hugentobler, Oliver Montenbruck, Peter Steigenberger
Summary: Each Galileo satellite provides coherent navigation signals in four frequency bands. This study evaluates the quality of Galileo satellite products determined by using different dual-frequency and multi-frequency measurements based on different ground networks. The results show that the orbit precision determined from E1/E6 dual-frequency measurements is worse than that from other dual-frequency solutions. Multi-frequency measurements have advantages over dual-frequency for precise orbit determination, especially in small networks. Satellite phase bias products determined from a 20-station network are precise enough for precise point positioning applications with ambiguity resolution.
JOURNAL OF GEODESY
(2023)
Article
Geochemistry & Geophysics
Oliver Montenbruck, Peter Steigenberger, Steffen Thoelert, Daniel Arnold, Grzegorz Bury
Summary: The GENESIS mission in 2027 will integrate four space-geodetic techniques in medium Earth orbit to improve the accuracy and homogeneity of future terrestrial reference system realizations. A comprehensive analysis of GNSS coverage was performed to assess the expected contribution of Global Navigation Satellite System tracking, showing that a single-antenna system is a viable alternative to the initial dual-antenna configuration considered.
JOURNAL OF GEODESY
(2023)
Article
Engineering, Aerospace
Oliver Montenbruck, Peter Steigenberger, Ningbo Wang, Andre Hauschild
Summary: This study provides a comprehensive assessment of broadcast group delays and differential code biases (DCBs) for all open BeiDou signals based on one year of data. The daily DCB estimates have a precision of 0.1 ns, but there is a notable variation in the estimated DCBs depending on the receivers used, causing inconsistencies between BeiDou-2 and BeiDou-3 satellites at the few-nanosecond level. Satellite-specific offsets can be identified in broadcast group delay values and clock offsets, which are a limiting factor for single point positioning and timing. The use of modernized B1C/B2a signals is recommended to reduce signal-in-space range error (SISRE) and improve product consistency from heterogeneous receiver networks.
NAVIGATION-JOURNAL OF THE INSTITUTE OF NAVIGATION
(2022)
Proceedings Paper
Remote Sensing
Ozge Gizem Esenbuga, Andre Hauschild, Peter Steigenberger
PROCEEDINGS OF THE 33RD INTERNATIONAL TECHNICAL MEETING OF THE SATELLITE DIVISION OF THE INSTITUTE OF NAVIGATION (ION GNSS+ 2020)
(2020)
Article
Geochemistry & Geophysics
Basara Miyahara, Laura Sanchez, Martin Sehnal, Michael Pearlman, Detlef Angermann, Thomas Gruber, D. Angermann, T. Gruber, M. Gerstl, R. Heinkelmann, U. Hugentobler, L. Sanchez, P. Steigenberger
JOURNAL OF GEODESY
(2020)