THREDDS Data Server (TDS) and Data Discovery

The THREDDS Data Server (TDS) in conjunction with the OAI Harvester functions as an enterprise-level middleware facilitating various core services such as registration, security, ordering, and querying using web service technologies. The server employs the NetCDF-Java (CDM) library and supports multiple access methods including OPeNDAP, HTTP, and WCS for accessing Earth Observation (EO) resources. It catalogs datasets and collections, with over 2200 collections and 60 million granules published from various sources including NASA and international partners. The TDS uses metadata records to harvest datasets and provides information such as title, summary, publisher, latitude/longitude bounding box, and variable names. The server aggregates datasets using NcML to make multiple files into a single logical dataset and employs web services for discovery, including a Resolver service and Dataset Query Capability (DQC). However, challenges remain, including the need for better handling of queries and standardization of protocols.