全国干旱遥感监测运行系统的研制

该研究利用1981－1994的NOAA AVHRR 8km分辨率的NDVI资料，以及对应时段全国102个固定农业观测站的20cm深的土壤湿度资料，建立了植被状态指数（VCI）与土壤湿度之间的统计模型，由土壤湿度旱情等级标准来换算出每旬用VCI进行干旱监测的旱情等级标准，以确定出全国的旬旱情分布状况，在此工作的基础上建成了“全国干旱遥感则运行系统”，该运行系统使遥感手段监测全国干旱成为可能，将能提供每年3－9月每旬全国的干旱监测情况，为国家有关决策部门提供干旱减灾的决策依据。     

Integration and Sharing of Geo-spatial Data Based on Data Engine

Through analyzing the principle of data sharing in the database system, this paper discusses the principle and method for integrating and sharing GIS data by data engine, introduces a way to achieve the high integration and sharing of GIS data on the basis of VCT in VC , and provides the method for uniting VCT into RDBMS in order to implement a spatial database with object-oriented data model.     

Component-based topological data model for three-dimensional geology modeling

On the study of the basic characteristics of geological objects and the special requirement for computing 3D geological model, this paper gives an object-oriented 3D topologic data model. In this model, the geological objects are divided into four object classes: point, line, area and volume. The volume class is further divided into four subclasses: the composite volume, the complex volume, the simple volume and the component. Twelve kinds of topological relations and the related data structures are designed for the geological objects.     

面向服务的城乡规划辅助决策系统实现

城乡规划建设迫切需要信息化决策支持手段.文章从整体上详细地设计了城乡规划辅助决策系统的框架以及数据库:以GIS为核心,以ArcGIS Server为开发平台,采用Flex开发语言,设计并开发了城乡规划决策统一平台;基于面向服务的思想,在一体化集成框架的基础上,对城乡规划辅助决策系统数据库设计进行了论述,并对数据库设计中所涉及到的控制性详细规划的各类矢量地理空间数据进行了整合;初步实现了标准化的、统一的城乡规划辅助决策数据库.实验表明:该平台具有先进的网络服务特性、高度的集成性以及良好的移植性,为城市信息化管理辅助决策提供参考.     

当代云计算发展研究现状

地理信息技术和地理信息产业作为信息产业的重要组成部分,一直与其同步发展或紧随其后。目前,第三次信息化浪潮和未来技术的代表云计算正在迅速兴起,全球各大IT公司竞相进入云计算领域,抢占制高点;我国也高度重视这一战略性新兴产业,呈现出科研先行,政府推动,企业参与,风起"云"涌的态势。全球学术界和企业界密切协作,有力推动了云计算技术的发展。测绘地理信息界需要了解国际国内云计算研究发展现状。     

Designing thought,technical line and some theoretical issues on geospatial digital framework of China

Based on the developing tendency of present China's basic GIS, this paper discusses the designing idea for scales of 1∶10 000, 1∶50 000, 1∶250 000 and 1∶1 000 000 pyramidlike multi-layer and multi-resolution of the basic GIS. A technical line for the construction of basic GIS of the whole country and various provinces for sustainable development is put forward. And some important theoretical GIS issues touched by the technical process are discussed.     

t-GIS and environmental dynamic models

Temporal geographic information system (t-GIS) is a kind of computer information system that can display, process and analyze the micro-format distribution of temporalspatial information of real world. It includes both spatial geographic information and temporal information, and can analyze both the static geographic information and the dynamic geographic information.     

Investigating the land use characteristics of urban integration based on remote sensing data: experience from Guangzhou and Foshan

Abstract

Urban integration is an increasingly popular phenomenon. It is important to characterize the dynamic processes of urban integration from the perspective of geography. However, previous studies mainly focussed on the overall characteristics of a single entity and failed to consider inter-city influences. Therefore, this study aims to systematically investigate this phenomenon. Firstly, spatial clustering technique and landscape metric were used to analyze the temporal change of spatial layout. Secondly, we built multiple ring buffers of city boundary to reveal the directional differences in urban expansion. Lastly, we compared the observed land use data with the results simulated by cellular automata model. These experiments have shown that the urban expansion characteristics during the urban integration process are rather different from those of a single city, and the above methodology can effectively characterize the urban integration phenomenon. The successful example of Guangzhou–Foshan integration could also provide practical experience for other similar attempts.     

沙漠地区无人机影像连接点提取

提出了一种纹理自适应的影像连接点提取方法,有针对性地解决沙漠地区无人机影像对比度低、相似性强、纹理信息不均衡,经常会造成连接点过少甚至提取、匹配失败的突出问题。该方法利用影像金字塔进行粗匹配,建立影像之间近似单应变换关系;通过对原始影像分块计算灰度共生矩阵的熵来评估影像纹理指标,并据此实现特征点的自适应提取与匹配。实验表明,该方法能够得到数量较多、分布均匀、可靠性强的同名点。     

对流层映射函数对陆态网解算精度的影响

对流层映射函数是卫星高度角及其他一些因素的函数,它的好坏直接影响对流层延迟改正的效果。本文介绍了NMF、VMF1及GMF 3种模型,采用2016年陆态网及周边IGS站数据,通过GAMIT软件计算对比分析了3种映射函数对陆态网解算精度的影响。结果表明,在进行陆态网解算时,3种映射函数模型精度差别不大,截止高度角为10°时精度最佳。