一种空间应用与科学数据分发共享服务平台的设计与实现

针对载人航天空间应用与科学数据的在线分发共享需求,面向服务方式、业务流程和数据结构,分析了数据分发共享服务平台的功能与组成,设计了多层次、松耦合、易扩展的平台架构,解决了平台数据库逻辑模型设计、元数据自动提取、数据便捷在线服务、轨道仿真的技术问题与实现方式。平台应用可以实现海量、多源、异构空间应用与科学数据的统一,高效查询检索,以及典型应用成果宣传等;并已成功应用于天宫一号空间应用推广服务。

SMS4算法应用于空间数据加密的研究及实现

随着空间科学及民用应用任务的增多,空间科学及民用应用任务的数据安全性问题越来越突出。空间数据加密方式受到重量、功耗、资源等限制,需要花费尽量少的代价来实现数据加密。文章提出了对敏感数据采用软件加密的思路。通过对加密算法、运行模式的比较,选择使用我国学者吕述望研发的SMS4算法,计数器运行模式(CTR)。使用FPGA对CTR-SMS4算法进行了设计实现和仿真。结果表明,该算法占用资源较少,运行速度快,适用于空间数据加密。

空间数据库技术应用教学资源库的构建与运用

基于职业教育教学资源库建设主要原则,提出空间数据库技术应用教学资源库的建设思路、技术路线,对教学项目设计、知识树构建、资源库开发进行系统阐述,形成面向MOOC和SPOC的运用模式,并在教学实践中改进与完善。

多源空间数据融合技术探讨

地理信息系统的迅速发展和广泛应用导致了空间多源数据的产生,给数据的集成和信息共享带来不便。不同数据源,不同数据精度和不同数据模型的地理数据融合理论与方法的研究,对于降低地理数据的生产成本,加快现有地理信息更新速度,提高地理数据质量有着重要的现实意义。本文对多种空间数据融合的原理与方法进行了讨论,给出了空间数据融合的多种应用,并对数据融合的发展方向进行了展望。

构建面向个性化服务的特大城市云空间数据中心

特大城市测绘地理信息数据具有数据海量、增长快速、多源异构、频繁使用的特点。随着大数据和Web2.0时代的到来,传统的空间数据存储管理与共享服务模式存在成果缺乏整合和挖掘、空间信息服务被动且无差别性等缺点,难以满足用户不断提高的空间数据内容、服务响应速度和服务质量的要求,也难以适应因人而异的个性化空间信息服务的需求。本文对个性化服务和云空间数据中心构建的关键技术进行了研究,提出了个性化空间数据情境应用模式,以及一种基于Web客户端的个人异构空间数据在线集成方法,基于NoSQL实现了个人空间数据与传统空间数据服务集成,并以北京市为例基于私有云构建了安全可靠、高效运行、可扩展、用户参与度高、提供个性化服务的特大城市云空间数据中心。

CCSDS高级在轨系统协议吞吐量性能分析

简要介绍了CCSDS高级在轨系统(AOS)协议的信源特点,分析了影响AOS协议包业务吞吐量性能的因素,给出传输集中数据时的包业务吞吐量计算公式,讨论了吞吐量-包长、吞吐量-帧长关系曲线,并针对传输集中数据情况下以吞吐量为指标实现优化AOS协议配置给出了指导性建议,为CCSDS AOS协议的应用提供了参考。

基于密度聚类的低压台区归属关系及相位识别方法

[目的]供电部门记录的正确的拓扑信息有助于工作人员监测电网信息,分析故障,优化电网运行以满足低压配电台区精益化、智能化管理的需要。目前,各式新型用电设备及用户的加入使低压配电网络结构呈现出持续变化的特征,线路维护成本被大大提高。[方法]为此,提出基于密度聚类的低压台区归属关系识别方法。首先,提取智能电表有效电压数据生成高维时序电压矩阵;其次,采用t分布随机近邻嵌入方法(t-distributed Stochastic Neighbor Embedding,t-SNE)对高维时序电压数据进行特征提取与降维;然后,应用基于数据密度的噪声应用空间聚类方法(Density-Based Spatial Clustering of Applications with Noise,DBSCAN)对降维后的数据进行聚类分析,实现低压用户台区归属信息的识别;最后,对海南省三亚市某台区实际数据进行分析,并将所提方法与其他主流的拓扑识别算法进行对比。[结果]分析结果表明所提方法能够达到95%以上的台区识别准确率,高于目前其他主流的拓扑信息识别方法。[结论]文章中的方法在解决此类问题上具有有效性与优势性,可以为实际工程应用提供参考,为低压台区拓扑信息识别领域提供不一样的研究思路。

Design and Applications of Land Resources and Ecological Environment Information System: A Case Study of Zigui County in the Three Gorges Area of China

The design and applications of a land information system built upon ARC/INFO and ArcView are presented. The proposed system not only maintains all the advantages of the more conventional implementations but also enhances them in the following ways: 1) the application program interfaces (API) are used to transmit data and messages among different parts of the system; 2) the integrated system can support studies on land evaluations and ecological analyses by efficient management of attribute and spatial data and 3) correspondingly, spatial records and attributive records are linked by the same identifiers (ID). A case study application in Zigui County of the Three Gorges Area in China demonstrates that the system could employ land-use maps and land property data to predicate and analyze the land utilization changes in the past, present and future. The ecological environment analysis can be carried out with the data of land, economics and terrain map used, showing that the system can be widely applied, especially to survey land and environment resources in the countryside area.

Design and Implementation of mobile GIS application based on Android

This paper analyzes the key technology of mobile GIS development, discusses the design method of mobile GIS spatial data management, visualization of spatial data And Spatial data query, tinder Object oriented mode. And we develop a set of mobile GIS basic software platform in the Android platform, and tested in the mainstream smart mobile phone with Android operating system, test results show that the software platform can run smoothly. Other users can development a variety of mobile GIS to call the platform through an application service interface.

Application Geospatial Technology in Disaster Management

Disasters including natural and manmade make heavy losses in life and property each year. This subject can affect society, economy, and environment and can be a serious threat for development. In 10 years ago over 200 million people are have been effected both life and property. This figure is seven times more than losses in war. After the earthquake in Bam （a city in south Iran）, tsunami in south-eastern of Asia, fire in Australia, and other disasters, the management of disaster has been considered more than before. They have tried to use all facilities and equipment for reduction of disaster damage. Over 80% of necessary data in disaster management are spatial data. Spatial data and advanced technologies have an important role in disaster management because Geographic Information System （GIS） can help in identifying disaster points. GIS combines geospatial data, and hardware, software that can analyze data to produce information. GIS mainly involves saving and analysis of data according to spatial and attribute data. GIS can combine and analyze spatial and non-spatial data .We have made an attempt to consider disasters management according to facilities and role of Geospatial Technology in control of disaster （especially earthquake）.

Improving wavelet reconstruction algorithm to achieve comprehensive application of thermal infrared remote sensing data from TM and MODIS

According to the data characteristics of Landsat thematic mapper （TM） and MODIS, a new fu sion algorithm about thermal infrared data has been proposed in the article based on improving wave let reconstruction. Under the domain of neighborhood wavelet reconstruction, data of TM and MO DIS are divided into three layers using wavelet decomposition. The texture information of TM data is retained by fusing highfrequency information. The neighborhood correction coefficient method （NC CM） is set up based on the search neighborhood of a certain size to fuse lowfrequency information. Thermal infrared value of MODIS data is reduced to the space value of TM data by applying NCCM. The data with high spectrum, high spatial and high temporal resolution, are obtained through the al gorithm in the paper. Verification results show that the texture information of TM data and high spec tral information of MODIS data could be preserved well by the fusion algorithm. This article could provide technical support for high precision and fast extraction of the surface environment parame ters.

Reconfigurable-System-on-Chip Implementation of Data Processing Units for Space Applications

Application-specific data processing units (DPUs) are commonly adopted for operational control and data processing in space missions. To overcome the limitations of traditional radiation-hardened or fully commercial design approaches, a reconfigurable-system-on-chip (RSoC) solution based on state-of-the-art FPGA is introduced. The flexibility and reliability of this approach are outlined, and the requirements for an enhanced RSoC design with in-flight reconfigurability for space applications are presented. This design has been demonstrated as an on-board computer prototype, providing an in-flight reconfigurable DPU design approach using integrated hardwired processors.

Design of Service-Oriented Architecture for Spatial Data Integration and Its Application in Building Web-based GIS Systems

In this paper we propose a service-oriented architecture for spatial data integration (SOA-SDI) in the context of a large number of available spatial data sources that are physically sitting at different places, and develop web-based GIS systems based on SOA-SDI, allowing client applications to pull in, analyze and present spatial data from those available spatial data sources. The proposed architecture logically includes 4 layers or components; they are layer of multiple data provider services, layer of data in-tegration, layer of backend services, and front-end graphical user interface (GUI) for spatial data presentation. On the basis of the 4-layered SOA-SDI framework, WebGIS applications can be quickly deployed, which proves that SOA-SDI has the potential to reduce the input of software development and shorten the development period.