IOOS DMAC aims to make IOOS’ data findable, accessible, interoperabile, and reusable to the greatest extent possible.  

As an active community of practice, IOOS’ DMAC standards and requirements can evolve as necessary in order to incorporate recommendations from the community or recent advancements in best practices from other similar communities. These guidelines and requirements will be updated accordingly, with version controlled releases where possible.  

Data providers should implement the following requirements for distributing datasets, depending on the particular data type. Properly describing datasets, sensors, platforms, models, analysis or observation methods, and quality-control procedures with appropriate metadata or attribution is essential for the long-term usability and reuse of information. 

Note that the ISO XML Metadata Requirements apply to all data types.

For in situ physical/chemical data from moorings/shore stations: 

  • Publish in ERDDAP (ERDDAP-TableDAP) with IOOS Metadata Profile 1.2 compliance.  Adherence to the IOOS Metadata Profile implies compliance with netCDF CF and ACDD conventions, plus additional IOOS-specific attributes and dataset formatting requirements.
  • netCDF data files are recommended for raw data files underlying ERDDAP datasets, following the CF Discrete Sampling Geometry guidelines for in situ observations.  Other raw data formats that are compatible with ERDDAP can be used, however, the data provider should bear in mind that DMAC Storage and Archiving requirements may require netCDF files be submitted to NCEI for archiving

For physical/chemical profiling glider data:

For biological observation data: 

For model/gridded data: 

  • netCDF files compliant with netCDF CF, ACDD, and SGRID or UGRID conventions (as applicable), served via OPeNDAP protocol with WMS access enabled.  
  • Model data should be aggregated into best-available time series or forecast model run collection datasets.  
  • Use of THREDDS as the data server with all extensions enabled (ncISO, ncWMS). The ERDDAP GridDAP service can be used in addition to or in place of THREDDS for regular grids.

For geospatial/other data types: 

  • Remotely-sensed products (such as satellite or georeferenced raster imagery), or vector geospatial datasets should be served via Open Geospatial Consortium (OGC)-compatible services wherever possible.

ISO XML Metadata Requirements (all data types): 

  • All datasets should be represented/described in ISO 19115-2 XML metadata files and included in a Web Accessible Folder (WAF) or OGC Catalog Service-Web (CS-W) for harvest by the IOOS Catalog (see Catalog Registration section for more details).
  • In general, IOOS partners should follow the guidelines in the NOAA Data Documentation Procedural Directive to properly describe and document their datasets.

Available Resources:

Compliance Checker 
The IOOS Compliance Checker is a command line Python tool to check local/remote datasets against a variety of compliance standards, including community standards such as netCDF-CF, ACDD, and the IOOS Metadata Profile. For non-python users, there is also a Compliance Checker website where files can be individually run through the checker.

IOOS Documentation Portal
The IOOS Documentation Portal includes technical documentation with specific details for many of the data format requirements listed on this page. Data providers are encouraged to consult this resource for the most current version of IOOS’ DMAC technical documentation.

NOAA Metadata and Data Management Guidelines
Additional background materials on NOAA metadata practices and procedures, which are endorsed by IOOS, are available at the NCEI metadata site and metadata wiki page.

ESIP Marine Data Cluster Vocabulary Guidance
The marinedata-vocabulary-guidance repository managed by the ESIP Marine Data cluster contains actively-developed best practices for vocabulary usage in publishing marine datasets.  The guidance therein is for reference purposes and is not required to be followed to comply with IOOS requirements, unless specifically referenced in any of the above data type-specific requirements.


As an example of the evolution of DMAC, in 2017 IOOS began a transition from the OGC Sensor Web Enablement (SWE) and Sensor Observation Service (SOS) suite of standards to the ERDDAP data server as the basis for most in situ data dissemination (as described above).  Therefore, mention of DMAC SOS/SWE requirements for data publishing are no longer listed in these pages.  IOOS expects to complete the full transition to ERDDAP, including for dissemination of data to NDBC and the GTS, in 2022.