- Big Data GIS
- Web GIS Component
- An Improved Cellular Automata Model for Simulating Pedestrian Evacuation
- Probability Estimation of Future Earthquakes in China Based on Improved PSHA Model
- Big Data in Smart City
- Experimental Geography Based on Virtual GeographicEnvironments(VGEs)
- Research Advance and Application Prospect of UnmannedAerial Vehicle Remote Sensing System
- Introduction to Urban Computing
- Detecting “Hot Spots” of Facility POIs Based on Kernel Density Estimation and Spatial Autocorrelation Technique
- Integrated Space-Air-Ground Early Detection, Monitoring and Warning System for Potential Catastrophic Geohazards
- The Spatial-Temporal Pattern Analysis of City Development in Countries along the Belt and Road Initiative Based on Nighttime Light Data
- Oblique Image Based Automatic Aerotriangulation and Its Application in 3D City Model Reconstruction
- Review of Change Detection Methods for Multi-temporal Remote Sensing Imagery
- On Construction of China’s Space Information Network
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1959 Vol. 3, No. 3
Generalized Surveying Data Processing: From Geometric Parameters Calculation to Feature Information Extraction
With the rapid development of technologies in sensor, computer and robotics, the trends of multi-sensor integration and intelligent applications are shown in surveying field. Engineering surveying has developed in the direction of automation, dynamism and intelligence, and is widely used for high-precision measurement of large bridges, water conservancy hubs, high-speed rail subways, highways and other projects, as well as precision industrial measurement in aerospace, aviation, intelligent manufacturing and other fields. The expansion of application fields also puts forward new requirements for surveying tasks.The surveying data processing is no longer limited to the traditional pure geometric parameter estimation, but gradually expands to the generalized measurement data processing with both geometric parameters and feature information. We review the development process from classical measurement data processing to generalized measurement data processing, summarize the processing and analysis logic of multiple types of measurement data, and present the challenges of measurement data processing in the era of big data. The basic ideas and strategies of generalized measurement data processing are elaborated and illustrated with several typical cases.
Coseismic Deformation and Slip Distribution of the 2022 Luding Mw 6.6 Earthquake Revealed by InSAR Observations
Objectives: The 5 September 2022 Mw 6.6 Luding earthquake is the largest earthquake occurring on the Xianshuihe fault, Eastern Tibet in the past 40 years, and is of great significance for investigating the tectonic activity and assessing future seismic hazards in the region. Methods: In this study, we used Sentinel-1 and ALOS-2 synthetic aperture radar (SAR) images to retrieve coseismic surface displacements and then to determine the fault geometry parameters and slip distribution with a dislocation model in an elastic half-space. Results: Our results show that the earthquake is a left-lateral sliding event with a maximum LOS surface displacement of ~15 cm and ~21 cm for the Sentinel-1 and ALOS-2 radar images, respectively. Conclusions: The fault ruptured along an NNW-SSE strike, and westward at a dip of 72°. The slip was concentrated at depths of 0-10 km with a maximum fault slip of 2.23 m occurring at a depth of ~5.8 km. By analyzing the distribution of the coseismic landslides interpreted by optical images, it is found that the coseismic landslides were mainly located on the west side of the fault, which is consistent with the aftershock distribution and can be considered due to hanging wall effects.
Emergency Analysis of the Impact of the Luding Ms 6.8 Earthquake on Hailuogou Glacier
Objectives: An earthquake with the magnitude of Ms 6.8 struck Luding County,Ganzi Prefecture,Sichuan Province on September 5,2022,with the epicenter about 10 km away from Hailuogou Glacier.How Hailuogou Glacier was affected by the earthquake has been widely concerned by the society. Methods: Firstly,the glacier area is monitored based on normalized difference snow index using multi temporal Landsat 8 and Sentinel-2 optical satellite images.Secondly,Sentinel-1 synthetic aperture radar satellite image is used to monitor the displacement before and during the Luding earthquake based on pixel offsettracking technology. Results: The results indicate that the area of Hailuogou Glacier shows a shaking trend from 2016 to 2022,which have a negative correlation with the daily average maximum temperature.While the velocity has a positively correlation with the slope gradient and the daily average maximum temperature.The Luding earthquake did not cause a significant increase in the velocity of Hailuogou Glaciers in a large range,but it significantly disturbed the front area of the ice waterfall. Conclusions: The possibility of direct disaster caused by ice avalanches after the earthquake was low,but which increased the risk of disaster caused by debris flow.
Research on Emergency Evaluation of Landslides Induced by Luding Ms 6.8 Earthquake
At 12:52 on September 5, 2022, an Ms 6.8 earthquake struck the Luding County, Ganzi Prefecture, Sichuan Province. This event triggered extensive geological hazards in mountainous areas, leading to serious casualties. Rapidly and accurately obtaining the spatial distribution of induced geological hazards is crucial for emergency decision-making and rescue after an earthquake. Based on the global coseismic landslide database and deep learning algorithm, this paper built a near real-time prediction model of spatial distribution probability of coseismic landslides, and obtains the prediction results of the geological hazards induced by the Luding earthquake within 2 hours after the event. Through the post-earthquake unmanned aerial vehicle(UAV) and satellite remote sensing images, machine learning and deep learning algorithms were used to realize the automated recognition of large-scale geological hazards. A total of 3 633 earthquake-induced landslides with an area of 13.78 km2 were interpreted. Finally, integrating these landslide data, the model of was optimized afterwards, and the prediction results of coseismic landslides with a broader area and higher accuracy were achieved. The results show that the coseismic landslide prediction model can realize a rapid capture of spatial distribution of post-earthquake geological hazards, filling the blank period before the acquisition of post-earthquake remote sensing images and providing support for post-disaster emergency rescue. Intelligent identification technologies based on UAV and satellite remote sensing images are effective means to rapidly obtain the vital information of large-scale geological hazards. The achievements obtained in this paper played an important role in the emergency rescue after the Luding earthquake.
A New Paradigm of Remote Sensing Image Interpretation by Coupling Knowledge Graph and Deep Learning
Summary and Prospect of Indoor High-Precision Positioning Technology
High-precision indoor positioning technology is of great significance to the development of national economy.In recent years, with the increasing demand for location services and the continuous iteration of technology, indoor positioning continues to develop towards high precision and seamless. In the case that the satellite signal cannot cover the indoor, the high-precision indoor positioning technology has become a research hotspot, and a variety of positioning sources and corresponding positioning principles have been developed. Aiming at the latest development status of high-precision indoor positioning technology, we divide into high-precision positioning methods based on geometric relation, fingerprint matching, incremental estimation and quantum navigation according to different positioning principles. We introduce the positioning principle of various methods, discuss and analyze the current technology development, summary the characteristics of high-precision indoor positioning technology, and discuss the future development trend of multi-source, intelligent and popular. Through the analysis of different positioning principles and technologies, it has reference value for the future study of indoor high-precision positioning sources and fusion positioning methods of different positioning sources.
Applications of UAVs in Antarctic Scientific Research: Progress and Prospect
Intelligent Map Image Recognition and Understanding: Representative Features, Methodology and Prospects
Rapid Measurement of Flatness of Oversized Floor of Speed Skating Oval in Winter Olympic Games
Smart City Awareness Base Station: A Prospective Integrated Sensing Infrastructure for Future Cities
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