Based on the P-wave travel-time data of 2 538 earthquake events(M_L≥1.0) recorded by 198 fixed stations of CENC from 2019 to 2023, the three-dimensional velocity structure of the crust in this area is inversed by double-difference tomography, earthquake relocation via double-difference tomography and waveform cross-correlation for enhanced accuracy and reliability, it reveals the coupling relationship between crustal structural heterogeneity and seismic activity under the background of craton destruction. The results show that after relocation, the root-mean-square(RMS) of seismic travel time residuals is reduced from 1.09 s to 0.52 s, and the residual average is optimized from －0.33 s to 0.02 s, the accuracy of the velocity model has been improved. Set four profile lines distributed in the Shanxi Jinzhong fault zone, Yanshan structural zone, Tangshan fault zone, Xingtai-Handan fault zone and other fault zones where earthquake events are more concentrated. Velocity structure analysis reveals that most seismic events are clustered within transitional zones between high- and low-velocity anomalies, the crustal thickness exhibits significant lateral heterogeneity. In the volcanic rift basin of Datong, Shanxi province, enhanced thermal-chemical upwelling corresponds to prominent low-velocity anomalies. The Yanshan tectonic zone displays alternating low-velocity and high-velocity anomalies, reflecting unstable stress conditions and structural anisotropy. Multiple strong earthquakes along the Tangshan fault zone predominantly occur within transitional zones between high-velocity and low-velocity anomalies. The Xingtai-Handan fault zone demonstrates concentrated seismic events likely triggered by lithospheric delamination processes associated with high-velocity anomalies.The dynamic mechanism of the destruction of the North China Craton is jointly dominated by lithospheric delamination, thermochemical erosion, and mantle convective erosion induced by the subduction of the Pacific plate, providing new geophysical constraints for understanding the stability evolution of the craton and the mechanism of strong earthquake propagation.

This study employs time-series InSAR technology to extract the interseismic surface deformation field along the Anninghe-Zemuhe fault zone on the eastern margin of the Sichuan-Yunnan rhombic block. We further invert the interseismic slip rates and locking depths of the fault system. Key findings include: the cross-fault InSAR deformation velocity gradient along the Anninghe fault increases progressively from ~2 mm/a in the northern segment to ~2.5 mm/a in the southern segment, whereas the Zemuhe fault exhibits a relatively smaller gradient of ~1.8 mm/a.Slip rates along the Anninghe fault vary spatially: ~2.8 mm/a at the northern Shimian segment, ~4.0 mm/a at the central Mianning segment, and ~3.2 mm/a at the southern Xichang segment. The Zemuhe fault shows a decreasing slip rate from ~3.1 mm/a in the northern segment to ~2.6 mm/a in the southern Ningnan segment.Locking depth analysis reveals maximum values (~37.8 km) beneath the Xichang segment, gradually shallowing northward to ~5.0 km at Shimian and southward to ~13.2 km at Ningnan.These results demonstrate that the Xichang segment, characterized by higher slip rates and deeper locking depths, exhibits enhanced seismic potential, consistent with its historically dense seismicity. This spatial correlation between geodetic deformation patterns and seismic activity provides critical insights into strain accumulation processes within this active tectonic boundary.

To investigate the response of L-band ionospheric scintillation to equatorial anomaly characteristics in low-latitude regions, this study utilizes L-band scintillation observation data from three Australian stations(Darwin, Weipa, and Willis Island) combined with global ionospheric VTEC data provided by the Chinese Academy of Sciences(CAS).The study examines the relationship between ionospheric scintillation and VTEC equatorial anomalies under geomagnetically quiet conditions. Results show a significant positive correlation between ionospheric scintillation and equatorial anomaly characteristics at the three stations. On scintillation days, the ionospheric VTEC peak-to-valley difference, peak-to-valley ratio increase, and gradient changes are more pronounced. This paper reveals the response mechanism and investigates the correlation between VTEC and its gradients with scintillation, which is significant for the rapid identification and judgment of scintillation phenomena and for GNSS engineering applications.

Based on hourly-resolution zenith tropospheric delay(ZTD) data from 35 GNSS stations in the Greenland region spanning the period from 2010 to 2021, combined with ERA5 reanalysis datasets and T_m model, precipitable water vapor(PWV) over the region was retrieved. Subsequently, the principal seasonal and diurnal variation characteristics, including annual, semi-annual, diurnal, and semi-diurnal cycles, were investigated. The results indicate that the GNSS stations in Greenland exhibit a certain degree of autocorrelation, with the summer season showing weaker autocorrelation compared to other seasons. The amplitude of the annual component ranges from 2 to 7 mm, while that of the semi-annual component ranges from 0 to 3 mm, with relatively minor interannual variations in their phases. The maximum values occur in summer, and the minimum values in winter. The diurnal component is only pronounced at a few stations, with amplitudes around 0.08 mm. After removing the annual, semi-annual, and diurnal components from the time series to obtain the residual time series, the maximum RMSE ranges from 1.30 to 3.65 mm, with an average RMSE of 2.08 mm. Notably, the RMSE values are relatively higher in the northern region and lower in the southern region.

A multi-scale prediction model(referred to as C-TCN-A) based on complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN) and temporal convolutional network-attention mechanism(TCN-Attention) algorithms is proposed, which can be effectively applied to missing data imputation and future trend prediction of GNSS elevation time series. The model first employs CEEMDAN for multi-scale decomposition of time series, then utilizes TCN-Attention for prediction and reconstruction of different scale components to obtain final results. To validate the model's performance, 12 observation stations were selected for 1-day and 5-day predictions, with comparisons made against multiple other models. Results demonstrate that in 1-day prediction, C-TCN-A reduces RMSE and MAE by 35%-40% and 36%-41% respectively while improving correlation coefficient R by 25%-29%. For 5-day prediction, it achieves reductions of 20%-26% in RMSE and 20%-28% in MAE, with R increasing by 26%-33%. To verify the model's universality, C-TCN-A was applied to 99 stations from the crustal movement observation network of China(CMONOC) for 1-day and 5-day predictions. Results indicate generally favorable RMSE and MAE metrics with concentrated error distribution, where most errors remain below 4 mm. Spatial analysis reveals regional performance differences, with optimal results achieved in the northwestern region.

Previous ZWD models over China only consider the effects of elevation, latitude and meteorological parameters, without taking into account the impact of monsoon climate and ocean water vapor transport on ZWD estimation. To solve this problem, we take bias correction as the breakthrough point, analyze the spatial distribution of RMSE and bias of ERA5-ZWD estimation value obtained by the ERA5 data integration method and inversion method over China from 2016 to 2019. Then, the regional bias correction model over China based on RF_Adaboost neural network is established using the ERA5 and radiosonde data from 2016 to 2018. The results show that the bias of ERA5-ZWD estimation value in 2019 is significantly reduced after correction, and the RMSE is significantly reduced in the eastern coastal areas and southern regions of China.

By establishing a BDS transmission reference control surveying model, the paper compares and analyzes the high-precision control surveying positioning performance differences between BDS-3/BDS-2 and BDS-3+BDS-2. Nine first-order control points of a project in Beijing and three IGS tracking stations in China and its surrounding areas were selected to establish a high-precision control surveying positioning network that supports both GPS and BDS-3/BDS-2 signals. Continuous observation data from three time periods(days 153-155 of 2023) were selected, and four schemes were designed for data processing. The positioning performance was compared and analyzed from two aspects: the transmission results of the initial reference and the adjustment results of control surveying. The results show that compared with GPS, BDS-3 and BDS-3+BDS-2 have only millimeter-level differences in N, E, U, horizontal, and point directions, while BDS-2 has differences ranging from millimeters to centimeters in the U and point directions, and only millimeter-level differences in the N, E, and horizontal directions. The measurement accuracy of BDS-3 is basically equivalent to that of BDS-3+BDS-2, while BDS-2 has lower accuracy than the other two, especially in the U direction.

To address the challenges of excessive noise points and weak effective signals in satellite laser ranging(SLR) echo data, which hinder accurate and rapid signal identification, this study proposes a composite real-time signal identification method. The method integrates an improved traditional histogram-based approach with the Graz fast filtering algorithm, optimizing both identification accuracy and processing efficiency. A simulated platform was established to replicate signal generation processes, preliminarily validating the algorithm's advantages. Experimental validation using measured data(1 ms per data point) demonstrated that the proposed algorithm achieved a false detection rate of 8.71%, significantly lower than the 32.71% and 43.52% rates of two conventional secondary filtering algorithms, while maintaining comparable missed detection rates(about 10%). Post-processing analysis of 1 million echo datasets(100 000 echoes per satellite for 20 satellites) revealed an average computation time of 4.31 s, outperforming the conventional algorithms(7.28 s and 12.45 s).

In order to simultaneously improve the efficiency and reliability of point cloud plane segmentation, based on the multi-scale supervoxel and region growing algorithm, supervoxels are used as the growing units, and the voxel region growing algorithm is used to achieve fine point cloud plane segmentation. The results show that the proposed method has good segmentation effect on both indoor and outdoor point cloud data, which is superior to RANSAC, Khaloo and global energy optimization methods. Moreover, the Precision, Recall and F₁-score of the method in this paper are all higher than 0.90.

In this paper, the stochastic finite-fault method is used to simulate the ground motion of the Wulong M_S5.0 earthquake. The simulation results for four stations within 100 km of the epicenter showed that the simulated acceleration time histories, peak ground acceleration, and response spectra are generally consistent with the actual records. Some discrepancies were observed at individual stations due to the influence of model parameters and environmental noise. Simulations were performed for 323 grid points within 100 km of the epicenter, and the spatial distribution characteristics of the ground motion obtained were consistent with the intensity field survey data. This study provides data support for seismic fortification and risk assessment in the Chongqing region and has both theoretical and practical significance for mitigating earthquake disasters.