• NASA ECHO: as a spatial and temporal metadata registry,
NASA ECHO enables different users to search and access
a large amount and variety of the Earth Observing System
(EOS) data at the NASA Distributed Active Archive Centers
(DACCs). ECHO’s Earth Science Metadata Conceptual
Model (EESMCM) covers most conceptual descriptions
at two levels for data granule and collection, such
as campaign, processing level, online access, sensor name,
and spatial and temporal attributes. ECHO’s Application
Programmers Interface (API) supports Web-based protocols
(SOAP and REST) and messaging formats to accommodate
a wide range of clients to search for and order
Earth science granules, or retrieve and manipulate granule
metadata.