Virtual geographic environment-based integrated rockfall risk simulation method for canyon bridges

Bridges located in mountainous areas are vulnerable to rockfall accidents, posing a threat to bridge engineering construction and operation safety in these regions. Under the coupling effect of complex environments and engineering disturbances, integrated rockfall risk simulation has become increasingly important for canyon bridge structural protection in long-term construction and operation phases. One of the main scientific challenges in rockfall risk simulation is studying the interaction between rockfalls and the topography and engineering environments during consecutive contacts. To systematically simulate the integrated bridge rockfall risk, an integrated construction of multivariable elements coupled with rockfall risk environments and scenarios is required. In this article, we proposed a VGE-based integrated rockfall scenario simulation method that uses the “associated representation—integrated modelling—interactional simulation” core strategy. Our method constructs a virtual rockfall risk environment by fusing multisource data to represent rockfall factors that induce rockfall disasters, hazard-forming environments, and elements at risk. We design rockfall scenarios under different bridge engineering construction conditions and extreme environmental conditions to analyze the interactional rockfall risks. The results demonstrate that our method enables a systematic analysis of the potential integrated rockfall risk, providing realistic reference value for the timely and effective disposal of emergencies, and reducing the harm and losses caused by such emergencies.     

顾及用户体验的三维城市模型自适应组织方法

传统基于“图层付象”的组织方法,没有考虑三维城市模型的不同内容以及不同细节层次的粒度差异,导致在网络环境下的传输效率低,难以满足多用户并发访问的流畅可视化。深入分析了大范围漫游与小范围聚焦的用户体验特点,通过元数据统筹管理和对象离散化,即时响应用户请求,减少无效数据传输,保证了多用户并发环境下的高效调度和浏览。针对模型LoI)和分解的对象,设计了结构统一的对象ID,隐式存储关联关系并支持分布式模型存储管理。以分布式数据库MongoDB为平台进行实验,验证了本文方法的可行性和有效性。     

利用TrackRT进行GPS实时动态形变监测研究

在相对实时动态定位软件TrackRT的基础上进行二次开发,完善了数据流实时传输与解码,并设计了两组模拟地面运动的观测实验,分别对TrackRT水平向和垂直向上的内外符合精度进行了评定。结果表明,在观测数据质量较好的情况下,实时定位水平分量精度优于2cm,垂向分量精度优于4cm。     

RTK技术在工程应用中若干问题的探讨

简单介绍RTK的应用原理及方法,并就RTK在工程应用中的若干问题提出解决方案.同时指出RTK技术在理论和实践上须关注的儿点问题.     

An approach to aid INS using time-differenced GPS carrier phase (TDCP) measurements

This paper presents a simple and effective approach that incorporates single-frequency, L1 time-differenced GPS carrier phase (TDCP) measurements without the need of ambiguity resolution techniques and the complexity to accommodate the delayed-state terms. Static trial results are included to illustrate the stochastic characteristics and effectiveness of the TDCP measurements in controlling position error growth. The formulation of the TDCP observation model is also described in a 17-state tightly-coupled GPS/INS iterative, extended Kalman filter (IEKF) approach. Preliminary land vehicle trial results are also presented to illustrate the effectiveness of the TDCP which provides sub-meter positional accuracies when operating for more than 10 min.     

测绘工程专业人才培养模式的研究与实践

本文从学校定位及专业实际出发,探讨了测绘工程专业目前存在的问题,研究测绘工程专业人才培养模式和培养计划的基本思路及课程结构体系.从专业设置管理体制的建立、测绘工程专业专项建设经费的设立、实训基地的建设、现代化教学手段等方面对人才培养模式及培养计划实施的保障体系进行了探讨.     

DZJ2激光垂准仪使用方法及指标的校正

介绍了DZJ2激光垂准仪的性能及基本指标的校正方法,为用户在使用DZJ2激光垂准仪过程中几种基本指标参数的校正提供参考.     

常用全站仪的电子校正方法

介绍了常用全站仪基本指标的校正方法,为用户在使用全站仪过程中保证仪器的精度提供参考。     

RTK配合全站仪在数字化测图中的应用

本文主要叙述了RTK配合全站仪进行数字化测图的可行性,介绍了RTK的系统组成、工作原理,并对RTK配合全站仪联合测图的作业流程进行了一系列论述;指出了RTK与全站仪联合进行数字化测图是一种高速度、高效率的新方法.     

t-GIS and environmental dynamic models

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