On March 4, 2010, the Goddard Earth Sciences Data and Information Services Center (GES DISC) reached a milestone by transitioning to the publication of metadata to the Earth Observing System (EOS) Clearinghouse (ECHO) in the ECHO 10 format.
The NASA-developed ECHO is a spatial and temporal metadata registry built by NASA's Earth Science Data and Information System program (ESDIS), enabling the science community to more easily use and exchange NASA's data and services. ECHO's main objective is to enable broader use of NASA's EOS data. It allows users to more efficiently search and access data and services and increases the potential for interoperability with new tools and services.
ECHO works along with its Earth Science Data Partners to gather metadata representing each partner's data holdings. This metadata is then made available through a published Application Program Interface (API), which exposes the necessary functionality for data discovery. This allows the data partners to focus on managing the availability of their information resources.
ECHO also supports the diversified user community by providing common programmatic interfaces, based on standards, with a common infrastructure. This enables the different stakeholder communities to build their own applications and user experiences that meet their user community needs. ECHO's Client Partners work in cooperation with the ECHO team to develop efficient and specialized user interfaces which access the ECHO API. These interfaces provide users with the benefit of the ability to search a single source for earth science data from the combined holdings of ECHO's Data Partners.
As an ECHO Earth Science Data Partner, the Goddard Earth Sciences Data and Information Services Center (GES DISC) sends ECHO metadata describing the data it archives. This is done in an automated fashion using a system based upon the Simple, Scalable, Script-Based, Science Product Archive (S4PA) architecture. As data files are received, they are automatically processed to extract the metadata, such as spatial and temporal coverage, which describes the data, and that information is written to files which are then transmitted via the Internet to ECHO, where the information in the file is "ingested" and loaded into the database that consolidates the information received from all of its data partners.
The ECHO system has evolved over the years. In April 2008, version 10 of ECHO was introduced. Version 10 included a number of modifications to the system architecture that added capabilities and significantly improved the speed and reliability of the metadata ingest subsystem. The schema, or structure, of the metadata received from data partners was revised to be more consistent and to adhere to standards. In order to make the transition to this revised metadata structure easier for its data partners, ECHO provided "adapters" to convert the structures used in ECHO 9 to the new ECHO 10 structures. Doing this allowed the data partners time to make the necessary revisions to their software to produce metadata with the ECHO 10 structure, without any interruption to the daily flow of metadata sent to ECHO.
Once the GES DISC completed the changes needed to their software, the new version of S4PA was implemented on all the GES DISC data archive machines. The metadata that the GES DISC sends to ECHO is now structured according to the new schema.