“天地图·陕西”浏览客户端的设计与开发

基于"天地图·陕西"发布的电子地图服务,设计开发了适用于不同系统下的电子地图浏览系统,依托当前较为流行的移动终端,可以实现"天地图·陕西"在线矢量地图和影像地图的触控浏览、移动定位、POI搜索、周边查询、市县导航、路径导航等功能,便于用户使用"天地图·陕西"的地图服务和功能服务。     

“天地图·酒泉”市级节点数据融合及制图优化的设计与实现

为了加快推进甘肃省"天地图"市级节点建设,以"天地图·酒泉"市级节点建设为例,通过对"天地图·酒泉"市级节点核心要素和"天地图·甘肃"省级节点数据研究,分析省级节点和酒泉市基础地理信息数据现状,结合ArcGIS制图功能,阐述了市级节点数据融合更新的技术方案和地图制图优化方法,可为其他市级节点建设和省市联动更新工作提供参考。     

矢量地图渲染技术研究

地图栅格瓦片具有更新周期长、地图风格固定、无法查询检索等缺点,为丰富地图风格、实现数据快速更新,采用基于WebGL的矢量地图服务渲染引擎,在客户端快速渲染矢量地图数据,实现了矢量地图数据的实时加载和渲染绘制,提高了地图显示效率,降低了系统响应时间,提供了风格多样的地图样式.主要从矢量地图数据组织与配置、矢量地图服务引擎和矢量地图前端渲染技术等方面展开研究,在"天地图·江苏"移动端已取得了应用成效.     

地理信息公共平台地图服务发布关键技术研究

在分析目前公共平台服务发布中存在问题的基础上,介绍了公共平台地图服务发布的3个关键技术问题,并以天地图·安徽数据更新项目为背景提供相应的解决方案,实现天地图省市级节点与国家公共平台在线地图表达的一致性。实践证明,研究成果应用在天地图和数字城市地图服务发布工作中是可行的。     

基于图库一体化的矢量电子地图制作——以“天地图·广东”为例

以"天地图·广东"矢量电子地图为例,结合广东省现有地理信息资源情况,简要分析了矢量电子地图制作的难点,提出了基于图库一体化的矢量电子地图制作技术方案,阐述了地图数据库建设、地图制图、地图瓦片切片3个生产阶段内容,有效地实现了矢量电子地图生产以及每年持续更新的目标,为"天地图"省、市级节点矢量电子地图的数据制作提供一定的技术参考。     

基于云架构的“天地图·常州”设计与实现

"天地图·常州"是国家测绘地理信息局主导建设的"天地图"大型互联网地图服务工程的市级节点,是数字常州的重要组成部分,也是常州市地理信息公共服务平台的公众版成果,从技术架构、部署方案、软件平台等多个方面阐述"天地图.常州"的设计与实现。     

浦东新区国土管理查询系统的设计与实现

本文主要研究"天地图·上海"网站地图API服务和数据资源为政府部门提供模块化地理信息服务的思路与模式,作者阐述浦东新区国土管理查询系统的总体架构、功能设计与技术实现,探讨一种将"天地图·上海"平台与政府政务公开工作有机结合的新应用模式。     

“天地图·河南”建设与应用研究

结合天地图全国版和"天地图·河南"的发展现状,重点阐述了"天地图·河南"的建设内容、建设特色以及应用。以红色地图和公众出行为例,详细论述了"天地图·河南"的特色,并提出了"天地图·河南"的统筹建设与未来规划,以解决其目前发展存在的问题。     

“天地图”服务聚合技术研究

"天地图"建设形成了丰富的地图服务资源。本文从"天地图"服务应用出发,结合服务聚合的思想,提出一种镶嵌式服务聚合方法,研究、实现了不同服务之间的聚合相关关键技术,在"天地图"建设和应用中具有一定的应用前景。     

基于“天地图”的位置服务平台的设计与实现

在位置服务平台建设过程中,为了解决全国性地图数据源、标准统一、详实性、现势性等问题,设计在地图数据源上采用国家、省、市三级的"天地图"地图服务。并且介绍了平台的分布式架构、多服务器集群服务技术、多终端协议集成服务技术及"天地图"接入实现应用的方法。     

山水林田湖生命共同体生态保护和修复

中共中央、国务院颁布的《生态文明体制改革总体方案》提出了六大生态文明理念,其中之一就是“山水林田湖是一个生命共同体”理念.论文以系统科学和景观生态学为理论基础,探讨了“山水林田湖生命共同体”生态保护和修复的指导思想、目标、方法、技术和制度. “山水林田湖生命共同体”实质是土地/景观综合体, “山水林田湖是一个生命共同体”理念提出了两个指导思想—系统观和生命观;目标—提高以“命脉”为核心的生态景观服务功能;方法—景观方法和绿色基础设施建设;工程技术—生态景观化工程技术;制度—以土地使用者为主体的综合景观管理.     

Economic, legal, and public policy issues influencing the creation, accessibility, and use of GIS databases

Rhind (1992) argued that government data policies and Intellectual Property Righr (IPR) considerations would play an increasingly large role in influencing the use of GIS. This has proved to be correct in general but the non-technical factors affecting data collection, supply, and price have become ever more complex. Indeed, one characteristic of the present situation is that it is now impossible to consider the legal, economic, and public policy issues in isolation. Consequently, this paper sets out to identify the interactions between them and the areas of conflict. It draws upon the literature of a much wider area than traditional GIS. This approach is essential because of two factors. The first is that GIS databases are presently of modest commercial value compared to some other data and hence key decisions on IPR, etc are being made outside our discipline. The second is that the nature of GIS databases is mutating rapidly through the wider use of multi-media and of the internet. It is concluded that the future is largely unpredictable in any detail since the interactions differ in different countries and at different moments in time. In many cases, however, revenue generation from sales or leasing of data or from services built upon data exploitation is likely to be a characteristic of both the public and the private sectors. Such charging has observable beneficial effects to set against the frequently claimed disadvantages, whether measured in financial, legal, or public access terms.     

“4D”技术及其应用

介绍“４Ｄ”（即数字地面模型、数字正射影像、数字栅格地图和数字线划地图）系列产品的生产流程、关键技术、及其在耕地保护、防灾减灾救灾和城市规划等方面的应用方法。     

Integrated adjustment of CHAMP, GRACE, and GPS data

Various types of observations, such as space-borne Global positioning system (GPS) code and phase data, accelerometer data, K-band range and range-rate data, and ground-based satellite laser ranging data of the CHAllenging Minisatellite Payload (CHAMP) and GRAvity Climate Experiment (GRACE) satellite missions, are used together with ground-based GPS code and phase data in a rigorous adjustment to eventually solve for the ephemerides of the CHAMP, GRACE, and GPS satellites, geocenter variations, and low-degree gravity field parameters. It turns out that this integrated adjustment considerably improves the accuracy of the ephemerides for the high and low satellites, geocenter variations, and gravity field parameters, compared to the case when the adjustment is carried out stepwise or in individual satellite solutions.Acknowledgments. This study has been supported by the German Ministry of Education and Research through the Geotechnologies Programme grants 03F0333A/CHAMP and 03F0326A/GRACE.     

Biases and accuracy of, and an alternative to, discrete nonlinear filters

The biases and accuracy of the extended Kalman filter (EKF) and a second-order nonlinear filter (SONF) are discussed from the point of view of a frequentist; these are often derived by applying the relevant conditional quantities to the linear Kalman algorithm under the Bayesian framework. The EKF and the SONF are biased, although the SONF has been derived in the hope of improving first-order filters. Unfortunately the biases of the SONF may be magnified further, because the second-order terms of the relevant Bayesian conditional quantities have never been properly used to derive the SONF from the frequentist point of view. The variance–covariance matrix of the SONF given in the literature is proven to be incorrect up to the second-order approximation, and the correct one is derived. Finally, also from the point of view of a frequentist, an alternative, almost unbiased SONF is proposed, if the randomness of partials is neglected. Received: 12 July 1997 / Accepted: 5 October 1998