瓦片影像地图快速配准与融合方法实现

为解决天地图中海量影像瓦片的快速配准和融合问题,文章针对主节点和省市级分节点影像瓦片地图的特点,设计了基于金字塔模型的地图瓦片快速空间精确配准和影像融合算法,并利用.NET语言编程实现了该算法。通过在天地图·四川建设中的实际应用表明,该算法能解决全色(黑白)影像无法应用于天地图省市级分节点建设的难题,对天地图省市级分节点建设有一定的应用价值。但由于融合数据范围较大且不同地区的数据质量存在差异,在融合过程中仍然需要大量的人机交互工作。     

基于Web2.0的课程网络教学平台建设——以地理信息系统概论为例

在Web 2.0技术飙发电举的今天,高校教育体制和教学模式也深受信息化影响,并逐渐走向教育信息化。本文从河南大学地理信息系统概论课程教学改革出发,在现有教学模式基础上,对Web 2.0在高校课程教学平台构建中的可行性进行探讨。通过对传统教学资源的整理挖掘,讨论了地理信息系统概论网络教学平台建设的模式和内容,提出了一套新的地理信息系统概论网络教学平台建设方案,探索了新的教学模式和资源库应用机制。     

地籍调查成图一体化技术研究

随着我国城乡经济的日益发展、城镇化的不断推进,各地方建设用地状况变化很大。全面、及时、准确地掌握土地利用信息,确保地籍成果的基础性、正确性和现势性,成为地籍调查的首要任务。本文面向地籍调查业务,以快速地籍成图为目的,设计了内外业一体化的地籍调查技术流程,确定了内外业数据交互格式及交互规则,研究了内外业一体化的地籍成图技术,设计了内业系统自动重构地籍图的方法流程,实现了地籍图快速生成。     

时空信息云平台在乱占耕地建房整治上的应用

为满足农村乱占耕地建房问题整治工作的需要,基于Web AppBuilder框架,以拥有宿主寄存技术的智慧黄山时空信息云平台为依托,利用ArcGIS Server服务发布技术结合即用型微件创建了农房核查程序,提供了地图操作、数据编辑、数据汇总统计等功能,为农房核查提供了方便快捷的技术支持。该程序具有易操作、可移植、可交互、响应时间短、用户界面友好等特点。     

Trophic relationships on a fucoid shore in south-western Iceland as revealed by stable isotope analyses, laboratory experiments, field observations and gut analyses

Rocky shores in the North Atlantic are known for their zonation patterns of both algae and animals, which can be expected to greatly affect food availability to consumers at different height levels on the shore. We tested the hypothesis that consumers would feed on the most abundant suitable food source in their surroundings. In total 36 species/taxa of common primary producers and consumers were sampled for stable isotope analyses from a sheltered fucoid shore at Hvassahraun in south-western Iceland. A selection of these species was also collected seasonally and from different height levels. Feeding experiments, field observations and gut analyses were also conducted. Our results were in good overall agreement with pre-existing knowledge of trophic relationships in the rocky intertidal. Consumers often appeared to be assimilating carbon and nitrogen from the most common diet in their immediate surroundings. The predator Nucella lapillus was thus feeding on different prey at different height levels in accordance with different densities of prey species. When tested in the laboratory, individuals taken from low on the shore would ignore the gastropod Littorina obtusata, uncommon at that height level, even when starved, while individuals from mid-shore readily ate the gastropod. This indicated that some kind of learned behaviour was involved. There were, however, important exceptions, most noteworthy the relatively small contribution to herbivores, both slow moving (the gastropod L. obtusata) and fast moving (the isopod Idotea granulosa and the amphipod Gammarus obtusatus) of the dominant alga at this site, Ascophyllum nodosum. The recent colonizer Fucus serratus seemed to be favoured. Selective feeding was indicated both by isotope signatures as well as by results of feeding experiments. Seasonal migrations of both slow and fast moving species could partly explain patterns observed.     

顾及特殊地物的等高线自动生成浅析

以自定义实体作为等高线自动生成的载体,构造了以AcDbEntity为基类的CContour实体．通过该实体自动生成所需要的等高线。在讲述了等高线自动生成的一般过程后,强调在构造Delaunay三角网时,应考虑到地性线和特殊地物对Delaunay三角网构造的影响,利用它们对构造好的Delaunay三角网进行修正,从而构造出准确的Delaunay三角网。这对等高线生成设计有参考意义。     

Simple and highly accurate formulas for the computation of Transverse Mercator coordinates from longitude and isometric latitude

A conformal approximation to the Transverse Mercator (TM) map projection, global in longitude λ and isometric latitude q, is constructed. New formulas for the point scale factor and grid convergence are also shown. Assuming that the true values of the TM coordinates are given by conveniently truncated Gauss–Krüger series expansions, we use the maximum norm of the absolute error to measure globally the accuracy of the approximation. For a Universal Transverse Mercator (UTM) zone the accuracy equals 0.21  mm, whereas for the region of the ellipsoid bounded by the meridians  ±20° the accuracy is equal to 0.3  mm. Our approach is based on a four-term perturbation series approximation to the radius r(q) of the parallel q, with a maximum absolute deviation of 0.43  mm. The small parameter of the power series expansion is the square of the eccentricity of the ellipsoid. This closed approximation to r(q) is obtained by solving a regularly perturbed Cauchy problem with the Poincaré method of the small parameter. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

基于OGC规范的遥感影像数据服务研究

以遥感数据共享为研究对象,针对传统遥感数据共享方法存在的问题,提出了基于WebService技术和OGC规范的遥感数据共享方案,设计了基于WMS和WCS的遥感影像数据服务,为用户提供在线遥感影像查询、浏览与获取服务,实现了遥感影像数据共享方法服务化。     

基于WMS的公路交通信息发布系统

采用WMS将公路交通专题地理数据与测绘框架地理数据进行集成与整合,实现跨行业和跨区域的空间地理数据的共享交互操作,并详细阐述系统的整体设计思路、系统架构及关键技术,最后对采用WMS在其它行业的应用进行展望。