摘要
Nowadays, NASA is producing several terabytes Moderate Resolution Imaging Spectroradiometer （MODIS） data everyday; how to find the data with criteria, such as specific times, locations, and scales using an international standard becomes more and more important. In this paper, a service-oriented architecture for use of the integration Earth Observation System Clearing- HOuse （ECHO） with the Open Geospatial Consortium （OGC） Catalogue Service--Web profile （CSW） is put forward. The architecture consists of three roles： a service requester （the user）, a service provider （the ECHO metadata server）, and a service broker （the GeoNetwork CSW and MODIS registry service middleware）. The core component-MODIS registry service middleware includes three components： metadata fetcher, metadata transformer, and metadata register. The metadata fetcher is used to fetch metadata from ECHO metadata server; the metadata transformer is responsible for transform metadata from one form to another; the metadata register is in charge of registering ISO19139-based metadata to CSW. A prototype system is designed and implemented by using the service middleware technology and a standard interface and protocol. The feasibility and the response time of registry and retrieval of MODIS data are evaluated by means of a realistic LPDAAC_ECS MODIS data center. The implementation of this prototype system and the experiment show that the architecture and method is feasible and effective.
现在， NASA 正在生产几 terabytes 中等分辨率成像分光辐射函数(MODIS ) 数据每天；怎么与标准发现数据，例如用一个国际标准的特定的时间，地点，和规模变得越来越重要。在这份报纸，为有户外 Geospatial 协会(OGC ) 目录服务鈥擶e b 侧面(CSW ) 的集成地球观察系统票据交换所(回响) 的使用的面向服务的体系结构被提出。建筑学由三个角色组成：一个服务请求者(用户) ，一个服务供应商(回响元数据服务器) ，和一个服务经纪人(GeoNetwork CSW 和 MODIS 注册表服务中间件) 。核心部件 -- MODIS 登记服务中间件包括三个部件：元数据 fetcher，元数据变压器，和元数据收款机。元数据 fetcher 被用来从回响元数据服务者取元数据；元数据变压器为从一种形式的变换元数据负责到另外一个；元数据收款机负责登记基于 ISO19139 的元数据到 CSW。一个原型系统被使用服务中间件技术和一个标准接口和协议设计并且实现。可行性和登记的反应时间和 MODIS 数据的检索借助于现实主义的 LPDAAC_ECS 被评估 MODIS 数据中心。这个原型系统和体系结构和方法可行、有效的实验表演的实现。
基金
Supported by the National 863 Program of China (No. 2007AA12Z230)
the National Natural Science Foundation of China (No. 40721001)
the IPV6 Program (No.126)
the Shenzhen Program (No. SY200806260042A, No. CXB200903090023A)
