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Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Pengcong Wang, Genming Luo, Dominic Papineau, Deng Liu, Hongmei Wang, Yiliang Li, Zongmin Zhu

Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Sarah C. Penniston-Dorland, Ikuko Wada, Natalie H. Raia, Andrew Steele, Emma S. Bullock, Xin Zhou, Besim Dragovic, Peter E. van Keken

Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Petra Maierová, Karel Schulmann, Taras Gerya

Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Neil Suttie, Andreas Nilsson, Nicolas Gillet, Mathieu Dumberry

Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Pascal M. Kruttasch, Karen Ziegler, Julian-Christopher Storck, Nicolas D. Greber, Aryavart Anand, Klaus Mezger

Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Qian Liu, Laura F. Robinson, Erica Hendy, Joseph A. Stewart, Tao Li, Tianyu Chen, Timothy D.J. Knowles

Publication date: 15 February 2025

Source: Earth and Planetary Science Letters, Volume 652

Author(s): Mingqing Zhu, Deguo Zhang, Peng Liang, Xiaoping Yang

Publication date: 1 January 2025

Source: Advances in Space Research, Volume 75, Issue 1

Author(s): Lu Liu, Hong Deng, Junwei Luo, Weiwei Wang, Jiafu Liu

Abstract

This study addresses the frequent convergence issues of satellite clocks within regional network, with a particular focus on the multifrequency advantages using data from 25 uniformly distributed reference stations across China. Experimental results demonstrate that incorporating the third frequency significantly enhances the accuracy of BDS-3 clock solutions, reducing the root mean square (RMS) by 44.5%. Additionally, employing a 2-min smoothing interval, multifrequency inclusion increases the wide-lane (WL) fixing rate by 30.4% at low elevation angles, which in turn leads to a marked improvement in narrow-lane (NL) ambiguity resolution. By leveraging phase-wide-lane observations, the stable wide-lane phase bias enables the continuous generation of inter-frequency clock bias (IFCB), ensuring reliable cyclic sequence construction even when satellites exit the observed region. The effectiveness of regional observable specific bias (OSB) on ambiguity resolution at the user level is highlighted, and over 95% of GPS, BDS-3, and Galileo NL fractional biases below 0.15 cycles could be achieved. Furthermore, the single-epoch convergence rates of multi-constellation precise point positioning (PPP) reach horizontal 91.9% and vertical 84.5% for multifrequency, a substantial improvement over the dual-frequency, which does not exceed 25%.

Nature Geoscience, Published online: 15 January 2025; doi:10.1038/s41561-025-01641-3

Author Correction: An ongoing satellite–ring cycle of Mars and the origins of Phobos and Deimos

Nature Geoscience, Published online: 15 January 2025; doi:10.1038/s41561-024-01626-8

Photochemical modelling suggests that H2 outgassing from crustal hydration could have supported transient warming episodes on early Mars in a CO2-rich atmosphere with abrupt transitions to cold climate states in a CO-rich atmosphere.

Nature Geoscience, Published online: 14 January 2025; doi:10.1038/s41561-024-01624-w

Near-daily sampling of volcanic ash during a three-month eruption reveals shifts in mantle-derived liquid magma (melt) composition, highlighting its potential as a monitoring and forecasting tool. These shifts align with the amplitude of volcanic tremor, a persistent seismic signal, suggesting a link between magma viscosity, shallow bubble escape dynamics, and tremor changes.

Abstract

In this paper, we propose a novel algorithm for fast frequency and phase synchronization of high-stability oscillators synchronized with 1 PPS signal from satellite navigation systems. The algorithm uses a model of a control object in the space of state variables and controls the frequency of an oscillator operating in a phase-locked loop. A new element is the introduction to the theoretical analysis and the design process, the time of entering synchronization. Currently, the literature lacks theoretical analysis and design methodology that considers the impact of the synchronization time on the choice of the steering algorithm and its parameters. All the data needed to determine the numerical values of the model were found experimentally for three different classes of control objects. Short synchronization times, a detailed description of the design methodology, and the use of values measured in the real system distinguish the proposed algorithm from the solutions described in the literature. The effect of optimization was achieved thanks to the algorithm’s two-stage operation. In the first stage, the algorithm aims to minimize the phase error quickly. The best solution for this stage is Sliding Mode Control (SMC). In the second stage, the algorithm strives to maximize the control quality, understood as minimizing the values of Maximum Time Interval Error (MTIE) and Time Deviation (TDEV). The Model Predictive Control (MPC) and Linear-Quadratic Regulator (LQR) optimal control algorithms were used at this stage. The paper also investigated the influence of the tuning parameters of these algorithms (weights as a function of cost) on the long-term behavior of the control system.

Nature Geoscience, Published online: 13 January 2025; doi:10.1038/s41561-024-01627-7

Space exploration has expanded the realm of geoscience to the outermost Solar System. A new generation of missions shines the way.

The micromechanics of friction has been investigated from the viewpoint of the healing of real contacts. In this study, the underlying processes of friction are discussed from the viewpoint of the contact junc...

Constraining the effective rheology of major faults contributes to improving our understanding of the physics of plate boundary deformation. Geodetic observations over the earthquake cycle are often used to e...

On February 8, 2022, approximately 40 of the 49 Starlink satellites were reported to have lost altitude, leading to atmospheric re-entry. SpaceX reported that the orbital decay on Starlink satellites was consi...

Nature Geoscience, Published online: 10 January 2025; doi:10.1038/s41561-024-01623-x

The SiO2 contents of erupted volcanic melts are correlated with persistent seismic signals that accompany eruptions—volcanic tremor—and may represent an eruption monitoring tool, according to a study of volcanic ash glasses from Cumbre Vieja volcano.

Abstract

In order to further improve the convergence rate and positioning accuracy of multi-frequency multi-system precise point positioning (PPP), an open-sourced software for fractional cycle bias (FCB) estimation (M_FCB) was produced based on MATLAB 2016a for GPS, BDS-2, Galileo, and BDS-3 satellite users. Based on raw frequency float ambiguity, the software can estimate ultra-wide-lane, wide-lane, narrow-lane combined FCB and raw frequency FCB. To validate the usability of the M_FCB software, 180 and 24 globally uniformly distributed multi-GNSS experiment stations were used to perform FCB estimation and triple-frequency uncombined PPP ambiguity resolution performance evaluation. The results show that the M_FCB software can generate stable and reliable FCB products. Particularly, Galileo satellites presented the best FCB stability. In addition, taking GPS/Galileo/BDS-2/BDS-3 fusion positioning as an example, the kinematic PPP after ambiguity resolution was significantly improved in terms of three-dimensional coordinate accuracy and positioning stability. Relative to the float solution, the average root mean square of the fixed-solution coordinate residuals in the east, north and vertical directions decreased by 30.3%, 12.5% and 16.0%, respectively.

Nature Geoscience, Published online: 09 January 2025; doi:10.1038/s41561-024-01618-8

This study examines the influence of agricultural irrigation on heat stress and contrasts it against local impacts of urbanization in North American cities using regional climate model simulations. The results indicate that irrigation decreases air temperature and increases relative humidity, with daytime urban moist heat stress reduced according to most indices.