基于CAD平台开发的实现3DSMAX快速建模方法研究

简要介绍了如何基于CAD平台开发构面软件,实现3DSMAX快速建模,提出了一套完整的思路,总结了实现快速建模的技术路线,并用实例进行了验证,达到了预期的3维效果,为实现数字城市和数字乡镇的3维景观显示提供了切实可行的方法,起到了抛砖引玉的作用。     

Fusion of multi‐resolution surface (terrestrial laser scanning) and subsurface geodata (ERT,SRT) for karst landform investigation and geomorphometric quantification

A multi‐method research design based on terrestrial laser scanning, GIS, geophysical prospecting (electrical resistivity tomography, refraction seismics) and sedimentology is applied for the first time to investigate enclosed karst depressions in an integrated way. Fusing multi‐resolution surface and subsurface geodata provides profound insights into the formation, geometry and geomorphologic processes of dolines. The studied landforms, which are located in the Dikti Mountains of East Crete, are shown to be filled by loose sediments of thicknesses of up to 30 m that mainly consist of fine‐grained material overlying solid bedrock at depths below 35 to 45 m. By combining subsurface observations with geomorphometric calculations, local doline genesis can be traced back to initial collapse of fractured bedrock followed by subsequent infilling with colluvials. In order to define crucial methodological requirements and guidelines for data fusion, both the impact of different elevation models and the influence of data resolution are assessed. Surface volumes of depressions derived by the digital surface model are 7–21% higher than the results obtained from the terrain model due to vegetation. Similarly, estimates of infill volume calculated on the basis of geophysical outcomes and elevation data differ by up to 13%. Calculations of the landforms' current volumes (i.e. total surface and subsurface volume), however, are fairly insensitive to raster resolution. Hence, the distinct geomorphologic properties of landforms (e.g. shape, terrain roughness, slope inclination) substantially determine the geomorphometric analysis of both surface and subsurface data. As shown by the findings, data fusion to integrate digital terrain, geophysical and sedimentological datasets of varied resolutions benefits geomorphologic studies and helps provide a comprehensive image of landforms. Copyright © 2013 John Wiley & Sons, Ltd.     

Response of an arch dam to non-uniform excitation generated by a seismic wave scattering model

Non-uniform ground motions are generated based on a single record available at a site and seismic wave scattering analysis. The Chino Hills 2008 earthquake records at the Pacoima Dam site are used to indicate the accuracy of the method. Dynamic analysis of the Pacoima dam-reservoir-foundation under uniform and non-uniform ground motions is carried out using the EACD-3D2008 software, and the results are compared to recorded responses at different locations on the dam. There is good agreement between computed and recorded displacements of the dam for non-uniform excitation. For uniform excitation, the displacements are underestimated in comparison with those obtained from recorded excitation. Significant intensification of stresses, especially near the foundation, and different patterns of stress distribution are observed for non-uniform excitation in comparison with uniform excitation. For uniform excitation maximum stresses occur in the crown cantilever near the crest, but for non-uniform excitation the maximum stresses occur along the sides and near the foundation.     

AVO analysis with partial stacking to detect gas anomalies in the GÜEPAJÉ-3D project

We applied analysis AVO with partial stacking to an onshore gas field in order to detect gas at the top of the Ciénaga de Oro formation (FCO), by using seismic gathers of the Güepajé-3D project. The technique was supported by petrophysical analysis of the Ayombe-1 well.The sensitivity of seismic response to changes in the saturating fluid was evaluated by fluid substitution technique in an interval of the Ayombe-1 well. As a result, a class I AVO anomaly at the top of the FCO was observed, even though the gas and water responses were similar. After applying AVO with partial stack technique at the top of FCO, AVO class I anomalies were observed in the Ayombe-1 and Güepajé-1 gas wells and none in the dry Güepajé-3 well. In spite of being reported with gas, the results in the Güepajé-2 well indicated any to an incipient class I anomaly related to a weak seismic response associated to gas.When the technique was applied to the seismic volume of the Güepajé-3D Project, a map of the direct gas indicator was obtained. The map shows a high correlation with the structural surface at top of FCO. Lithic factors such as compaction, cementation and carbonate overlaying the FCO and variable thickness of partial and full saturated layers, may cause anomalies in zones unlikely to contain gas.     

基于3维的基础测绘成果客户选图服务系统研究

探讨了GeoGlobe3维GIS技术在基础测绘成果客户选图服务中的应用,主要包括系统框架设计和具体功能。     

基于Web的3维数字社区建设方法与应用研究

提出了一种基于Web的3维数字社区建设方案与技术路线,对3维数据社区关键技术进行了研究,并结合具体应用。本文提出的数字社区平台建设思想,结合了Web计算机技术与3维地理信息系统技术,以期对数字社区平台建设提供有益借鉴。     

浅谈哈尔滨市群力新区地理信息系统建设

基于我院承担的"哈尔滨市群力新区地理信息系统"建设项目,从"创新"的角度简要介绍了系统建设框架、数据组织以及系统建设重点等内容。     

Riegl VZ-400三维激光扫描仪数据的建模的研究

三维激光扫描技术是近年来发展起来的一门新技术,其在众多领域中有非常广阔的应用前景。本文介绍了三维激光扫描仪目前的应用现状,以及原理和数据后处理方法。最后通过青海玉树山体建模实例叙述了Riegl VZ-400扫描仪如何获取数据、点云数据的拼接及三维模型的建立。     

矿区三维地质建模与地裂缝成因分析

为了分析在复杂地质条件下采煤引起的大规模地表裂缝的形成原因,本文以某矿区地裂缝为研究对象、数字化软件SURPAC为技术平台、岩体为主要区域变量,建立关于开采工作面、火成岩、地裂缝及断层的三维地质模型,并进行开采沉陷影响预计,通过分析裂缝成因中各相关地质条件的作用影响,得出了煤炭开采导致地下应力平衡被打破后造成地裂缝的主要因素,为预防和治理地裂缝提供了参考。     

A novel identifier scheme for the ISEA Aperture 3 Hexagon Discrete Global Grid System

ABSTRACT

Geospatial data is often spatially aggregated by the use of Discrete Global Grid Systems. References to grid cells are needed for the communication of such data, and different identifier schemes have accordingly been introduced in literature. These schemes suffer, however, from being hard to understand for non-experts, and the geometry of a cell cannot be inferred from its identifier without complex computations. In this article, a novel identifier scheme that encodes the geographic coordinates of the centroid of a cell is proposed, which comes at the cost of potentially being ambiguous in case of a very fine-grained grid. We reason and computationally demonstrate that ambiguity does though not occur for real-world applications. The novel identifier scheme minimizes the amount of data to be communicated, for example, between a server and a client application, and it allows to infer approximate geometries of the cells only by their identifiers.