Abstract: The dispersibility and heterogeneity of Earth Observation(EO) data sources make the discovery and access of EO data strenuous and time-consuming.Aiming at this problem,a data discovery system integrated with OpenSearch EO data service is proposed.It integrates EO data source based on OpenSearch standard,and provides unified discovery interface for EO data.It extends the query mode for unlimited query keywords query,establishes standard metadata model,and implements fast response in a massive query keywords collection and unified multi-source searching results presentation through Trie tree and mapping mechanism.It uses Java Emitter Templates(JET2) technology and makes XML files description of exogenous data services and keep the completeness of the system.A prototype system is implemented,and experimental results show that it can provide accurate results for multi-source data set search,provide unified meta data model and reduce 40% time cost compared with one-by-one search approach.

Key words: OpenSearch standard, Earth Observation(EO), data integration, metadata model, Java Emitter Templates(JET2) technology

摘要： 对地观测(EO)数据源分散与异构的特点导致数据获取耗时费力。为此,提出一种集成OpenSearch EO数据服务的统一数据发现系统。基于OpenSearch规范对EO数据源进行集成,并提供统一的发现接口,解决数据不易获取的问题。通过建立标准元数据模型,扩展查询模式为任意 关键字查询,利用Trie树和映射机制实现海量关键字集的高效请求响应与多源结果一致呈现。使用JET2技术并对外源数据服务进行XML文件描述,实现外源数据的轻便扩增,保持系统中数据集成的完备性。对系统进行原型实现,实验结果表明,该系统能正确反馈多源数据集查 询结果,提供统一元数据模型,与逐次单个查询方式相比可节约40%的耗时。

关键词: OpenSearch规范, 对地观测, 数据集成, 元数据模型, JET2技术

CLC Number: 

• TP391