A data porting tool for coupling models with different discretization needs

The presented work is part of a larger research program dealing with developing tools for coupling biogeochemical models in contaminated landscapes. The specific objective of this article is to provide researchers with a data porting tool to build hexagonal raster using information from a rectangular raster data (e.g. GIS format). This tool involves a computational algorithm and an open source software (written in C). The method of extending the reticulated functions defined on 2D networks is an essential key of this algorithm and can also be used for other purposes than data porting. The algorithm allows one to build the hexagonal raster with a cell size independent from the geometry of the rectangular raster. The extended function is a bi-cubic spline which can exactly reconstruct polynomials up to degree three in each variable. We validate the method by analyzing errors in some theoretical case studies followed by other studies with real terrain elevation data. We also introduce and briefly present an iterative water routing method and use it for validation on a case with concrete terrain data.     

车桥用水性单组分底面合一防锈涂料的制备与研究

针对车桥防护涂层的涂装特点,采用热融合接枝技术制备了一种稳定共融的水性单组分底面合一树脂新体系,并以该树脂为主要成膜物,通过正交实验优化涂料配方制备了车桥用水性单组分底面合一防锈涂料,阐述了其制备工艺并探讨了催干剂体系、防锈颜料体系和增稠触变体系对涂料以及涂膜性能的影响。     

全数字测量系统DAT/EM在数据采集中的应用

简要介绍了DAT/EM系统的主要部件和功能,结合HK09-0042-ST Lucia项目对DAT/EM系统内业作业的步骤流程进行了分析和归纳,并对DAT/EM系统与其他系统对比研究,由此总结了DAT/EM系统的性能优点。     

基于GIS黄水河流域下垫面类型划分研究

以龙口市黄水河流域为例,通过运用地理信息系统软件ARC／INFO对流域形态特征的模拟以及与水文本文要素的相关分析,从而将空间信息转化为水评议信息,以此为基础,确定了流域下垫面类型划分的理论依据、方法和步骤,为区域水资源的计算提供了基础条件。     

规则格网DTM快速构建算法研究*

规则格网(Grid)是数字地形模型(DTM)最常用的表示方法,有着广泛的应用。研究了基于离散点、三角网两种空间数据的规则格网快速构建算法。实验表明,分块索引方法及扫描线填充方法的引入实现了规则格网的快速生成,在大数据量条件下,效果也非常明显。     

大面积数字化成图DTM建立与地物编辑的方法研究

DTM建立与地物编辑方法是影响大面积数字化成图效率的主要因素．本文介绍如何在坎上下及地性线上加点，可以在建立DTM过程中不用考虑坎高及地性线等约束条件。从而提高DTM的建立速度。在数据分类基础上对地物进行分层绘制可以提高绘图效率．整幅绘制等高线及地物，利用窗口裁剪的方法进行分幅，可使地形图分幅达到无缝接边。     

利用GIS方法建立山区温度分布模型

提出了一种在气象站点实测数据基础上，利用ＧＩＳ技术建立山区温度分布模型的方法。通过建立数字地形模型（ＤＴＭ），获取影响山地温度分布的地形要素，并结合太阳年运动轨迹求出任一地点的天文太阳辐射值，同时考虑海拔高度、地理位置等影响气温的因素以及站点实测数据建立山区温度分布模型。     

Multipass hierarchical stereo matching for generation of digital terrain models from aerial images

This paper presents a new multi-pass hierarchical stereo-matching approach for generation of digital terrain models (DTMs) from two overlapping aerial images. Our method consists of multiple passes which compute stereo matches with a coarse-to-fine and sparse-to-dense paradigm. An image pyramid is generated and used in the hierarchical stereo matching. Within each pass, the DTM is refined by using the image pyramid from the coarse to the fine level. At the coarsest level of the first pass, a global stereo-matching technique, the intra-/inter-scanline matching method, is used to generate a good initial DTM for the subsequent stereo matching. Thereafter, hierarchical block matching is applied to image locations where features are detected to refine the DTM incrementally. In the first pass, only the feature points near salient edge segments are considered in block matching. In the second pass, all the feature points are considered, and the DTM obtained from the first pass is used as the initial condition for local searching. For the passes after the second pass, 3D interactive manual editing can be incorporated into the automatic DTM refinement process whenever necessary. Experimental results have shown that our method can successfully provide accurate DTM from aerial images. The success of our approach and system has also been demonstrated with a flight simulation software. Received: 4 November 1996 / Accepted: 20 October 1997     

基于ArcGIS的土方量计算与可视化

利用ArcGIS三维构面的特性,形象的构建地表、河道现状立体模型,同时根据场地、河道的设计标高,构建立体模型,然后选定统一参考面,计算两个模型到参考面的体积之差,可以快捷、准确地计算出挖填土方量。实践证明,这一算法较传统的根据等高线、高程点计算土方量的方法更加严密、准确、便捷。同时这一方法能根据要求灵活调整、分割土方计算区域,不需要对调整后的边界进行外业高程点数据处理就能快速实现分区域土方量计算。     

基于GIS技术的尾矿坝实时测量及其空间分析

为了及时撑握尾矿坝坑空间的变化,利用地理信息系统(GIS)的原理,使用Delaunay三角网的算法,结合VC和OPENGL设计应用程序,时尾矿坝进行测量并进行数据处理,由此生成尾矿坝的三维实体模型DTM,通过对其进行空间分析,为尾矿坝的监控和综合治理提供了科学依据.所设计的程序的运行速度快,精度高,可靠性好.