实时空间信息服务系统研究     

赖志坤  朱欣焰  李大军 《地理信息世界》2006,4(1):18-22

实时空间信息服务是第四代GIS的研究热点之一。本文在对实时空间信息服务研究的空间信息技术、RTPS技术、WebService技术进行分析与探讨的基础上,详细分析和论述了系统的总体结构、功能模块和工作流程,并通过实验系统予以验证。  相似文献   

对GIS中有关转向限制路径选择问题的探讨     

刘刚 《地理信息世界》2006,4(2):34-38

实时空间信息服务是第四代GIS的研究热点之一。本文在对实时空间信息服务研究的空间信息技术、RTPS技术、WebService技术进行分析与探讨的基础上,详细分析和论述了系统的总体结构、功能模块和工作流程,并通过实验系统予以验证。  相似文献   

服务网格及其在地质调查空间数据服务中的应用     

万波  方芳  杜小平 《地球科学》2006,31(5):645-648

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面向服务的分布式空间信息支撑平台   总被引：13，自引：10，他引：3  

吴信才  吴亮 《地球科学》2006,31(5):585-589

基于Web服务技术构建空间信息系统有助于提高其可扩展性和互操作能力, 该技术也是这一领域中的热点.提出了一种面向服务的模型框架, 并基于该框架提出了基于Web服务的网格层次体系结构, 并给出一种Web服务与空间信息技术相融合的机制, 介绍了基于Web服务的空间信息网格支撑环境的总体结构和设计原理, 为基于Web服务的空间信息系统设计与实现提供了一种新的方法.   相似文献   

我国海洋生态系统服务功能及其价值评估研究计划   总被引：24，自引：0，他引：24  

陈尚  张朝晖  马艳  石洪华  马安青  郑伟  王其翔  彭亚林  刘键 《地球科学进展》2006,21(11):1127-1133

国家海洋局于2005年启动了为期5年“海洋生态系统服务功能及其价值评估”研究计划。该计划的目标是建立具有我国海洋生态特征,适应我国社会经济发展水平的海洋生态系统服务功能定量模型和服务价值计算方法,并基于GIS技术开发生态系统服务价值评估系统,应用于评估渤海、黄海、东海和南海四大生态系统的服务价值和11个沿海省市区的近海服务价值,同时评估赤潮、病原生物和外来种导致的海洋生态系统服务价值损失,为实现人海和谐的海洋开发产业布局和用海活动提供定量评估技术支持,为基于生态系统的海洋管理提供理论支撑。目前,该计划已经建立了我国海洋生态系统服务功能分类体系、服务功能量化指标和服务价值计算指标体系,完成评估软件系统的设计。  相似文献   

The youngest lobe-dominated radio sources     

I. Owsianik  J. E. Conway  A. G. Polatidis   《New Astronomy Reviews》1999,43(8-10)

We present an analysis of multi-epoch global VLBI observations of the Compact Symmetric Objects: 2352+495 and 0710+439 at 5 GHz. Analysis of data spread over almost two decades shows strong evidence for an increase in separation of the outer components of both sources at a rate of 0.2h⁻¹c (for q=0.5 and H=100h km s⁻¹Mpc⁻¹). Dividing the overall sizes of the sources by their separation rates implies that these Compact Symmetric Objects have a kinematic age 10⁴ years. These results (and those for other CSOs) strongly argue that CSOs are indeed very young sources that probably evolve into much larger classical doubles.  相似文献   

Helical motions in the jet of blazar 1156+295     

X. Y. Hong  D. R. Jiang  L. I. Gurvits  M. A. Garrett  R. T. Schilizzi  R. D. Nan 《New Astronomy Reviews》1999,43(8-10)

The blazar 1156+295 was observed by VLBA and EVN + MERLIN at 5 GHz in June 1996 and February 1997 respectively. The results show that the jet of the source has structural oscillations on the milliarcsecond scale and turns through a large angle to the direction of the arcsecond-scale extension. A helical jet model can explain most of the observed properties of the radio structure in 1156+295.  相似文献   

VSOP monitoring of the Quasar 1928+738     

D. W. Murphy  S. J. Tingay  R. A. Preston  D. L. Meier  D. L. Jones  J. C. Guirado  A. Polatidis  J. E. Conway  H. Hirabayashi  H. Kobayashi  Y. Murata 《New Astronomy Reviews》1999,43(8-10)

We present the results from a campaign to monitor the relatively low redshift (z=0.3) circumpolar superluminal quasar 1928+738 with VSOP during the first Announcement of Opportunity period. The four epochs of data show that there have been substantial structural changes in this source near the core on the time-scale of a few months.  相似文献   

High resolution imaging of parsec-scale jets: the impact of the VSOP observations     

A. P. Lobanov  T. P. Krichbaum  A. Witzel  J. A. Zensus 《New Astronomy Reviews》1999,43(8-10)

Resolution improvements achieved with the ongoing space VLBI mission VSOP provide an excellent opportunity for studying compact, parsec-scale jets in active galactic nuclei. Visibilities on space baselines contain structural information that cannot be recovered by super-resolving ground-array data at the same frequency. We illustrate this by discussing the results of recent VSOP observations of parsec-scale jets in 0836+710 and 3C273.  相似文献   

The radio structure of 1803+784     

S. Britzen  A. Witzel  T. P. Krichbaum  T. W. B. Muxlow 《New Astronomy Reviews》1999,43(8-10)

We report on the progress of world array VLBI observations of the BL Lac object 1803+784 performed at λ=18 cm. A 16-station VLBI array, plus the phased VLA, and the 7-station MERLIN array simultaneously observed the source for 11 hours. These observations provide images of the transition region between the misaligned milliarcsecond- and arcsecond-jet. We show the MERLIN map and a combined full-array map at medium resolution. In addition we describe the present status of short-cm VLBI observations of this source.  相似文献