A service or service endpoint is an accessible URL providing data access via a standard (e.g. SOS, DAP, WCS). Services are harvested via CSW from the NGDC Geoportal on a nightly basis. The IOOS Catalog provides monitoring for uptime statistics and uses these services to extract datasets.
The current supported services are DAP, SOS, WCS, and WMS.
A dataset is some form of data produced by a service. Gridded data, point data, and observation data are just some of the datasets harvested from a service. A single service may produce one or more datasets. Datasets also contain summary variable and attribute information collected at the time the dataset is harvested. From this attribute and variable information, a compliance score is generated based upon how well the dataset adheres to the IOOS Asset Inventory version 1.0 specifications.
RAs have many options in their DMAC implementations depending on their workflows. Different services offer different capabilities; for instance, an SOS deployment via i52N allows a single Service endpoint to produce a large number of Datasets. Providing SOS via NcSOS via THREDDS results in a 1:1 mapping between service endpoint and dataset.