Collaborative Research: II: Integrating Digital Libraries and Earth Science Data Systems

开放网络数据访问协议（OPeNDAP）是基于内容访问在线地球科学数据集的领先网络协议。亚历山大数字图书馆（ADL）是世界领先的地理空间和地理参考信息数字图书馆。OPeNDAP和ADL的功能几乎是完全互补的，它们的结合将产生一组统一的网络接口，用于跨独立信息提供者的分布式网络进行基于查询的发现、评估、验证和检索地球科学信息。该项目通过以下方式集成ADL和OPeNDAP:(1)在现有的OPeNDAP服务器网络上实现ADL中的联邦发现系统；(2)在OPeNDAP协议中增加专题实时环境分布式数据服务（THREDDS）编目元数据（包括内联和第三方）；(3)为ADL/OPeNDAP数据集开发一个通用用户界面，类似于桌面“打开文件”对话框；(4)将OPeNDAP功能（内容选择和投影操作）添加到ADL查询中，以便相同的查询可以应用于OPeNDAP数据集的子集和其他图书馆馆藏（文本，GIS层等）。该项目在数字图书馆（侧重于基于查询的异构内容检索）和地球科学数据系统（侧重于对（相对）同质内容的功能访问）之间形成了一座综合桥梁。基于查询的科学数据内容访问与特定内容的图书馆馆藏访问的耦合将使广泛的科学家和学生社区能够使用相同的查询来比较图书馆中同行评审的知识与直接来自负责研究人员的最新研究结果。

The OPen Network Data Access Protocol (OPeNDAP) is the leading network protocol for content-based access to online Earth science datasets. The Alexandria Digital Library (ADL) is the world's leading digital library for geospatial and georeferenced information. The functionalities of OPeNDAP and ADL are almost perfectly complementary and their combination will yield a unified set of network interfaces for query-based discovery, evaluation, verification, and retrieval of Earth science information across a distributed network of independent information providers.The project integrates ADL and OPeNDAP by: (1) implementing a federated discovery system in ADL over an existing network of OPeNDAP servers; (2) adding Thematic Realtime Environmental Distributed Data Services (THREDDS) cataloging metadata (both in-line and third-party) to the OPeNDAP protocol; (3) developing a generic user interface, analogous to a desktop "open file" dialog, for ADL/OPeNDAP datasets; and (4) adding OPeNDAP functionality (content selection and projection operations) to ADL queries, so that the same query can apply to subsets of OPeNDAP datasets and to other library holdings (text, GIS layers, etc.).The project forms an integrative bridge between digital libraries with their focus on query-based retrieval of heterogeneous content and Earth science data systems with their focus on functional access to (relatively) homogeneous content. The resulting coupling of query-based access to science data content with content-specific access to library holdings will enable a broad community of scientists and students to use the same query to compare the peer-reviewed knowledge in a library against the latest research results direct from the responsible researcher.