The NOAA GEO-IDE UAF ERDDAP

The goal of this web site is to give you easier access to all of NOAA's data. ERDDAP (the Environmental Research Division's Data Access Program) is a data server that gives you a simple, consistent way to download subsets of scientific datasets in common file formats and make graphs and maps.

NOAA (the National Oceanic and Atmospheric Administration) is the U.S. federal agency with a mission to understand and predict changes in Earth's environment and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs.

GEO-IDE (the NOAA Global Earth Observation - Integrated Data Environment initiative) is a set of guidelines and best practices that establish a framework for improving the interoperability of NOAA's environmental information management resources. GEO-IDE is a project of the NOAA Data Management Integration Team (DMIT).

UAF (the Unified Access Framework) is a NOAA-wide effort to develop a gridded dataset integration capability. The capability is being developing using several de facto standards: netCDF, which provides the abstract data model, software libraries and a persistent binary format; the Climate and Forecast (CF) metadata conventions; the OPeNDAP protocol for web transport of data subsets; THREDDS XML catalogs which provide a distributed topology connecting data suppliers; and an OGC compatibility layer that provides access to the grids through WMS and WCS.

The initial focus has been to develop a NOAA-wide UAF THREDDS catalog of CF-compliant datasets (e.g. model outputs, satellite products, High Frequency radar observations, etc.) and to connect the catalog to other data servers (e.g., LAS and ERDDAP (this web site!)) and several popular client tools (e.g. MatLab, Google Earth) to enable direct access and use of the datasets.

ERDDAP (the NOAA NMFS SWFSC Environmental Research Division's Data Access Program) is a data server that gives you a simple, consistent way to download subsets of scientific datasets in common file formats and make graphs and maps. This ERDDAP installation makes all of the datasets in the NOAA-wide UAF THREDDS catalog and many additional datasets available via ERDDAP. The added benefits of using ERDDAP are:

• More Search Options - ERDDAP gives you many ways to search for interesting datasets (see the options at right), instead of just a tree (hierarchical) list of the datasets.
   
• More File Formats - ERDDAP gives you the ability to download subsets of the datasets in many common file formats (for example, .html table, ESRI .asc, Google Earth .kml, .mat, .nc, OPeNDAP .asc and .dods, .csv, .tsv, .json, and .xhtml) instead of just the OPeNDAP ASCII and binary formats.
   
• A Consistent Time Format - In ERDDAP, time when formatted as a number is always in "seconds since 1970-01-01T00:00:00Z" (which is UDUNITS-compatible) and,
  when formatted as a string, time is formatted according to the ISO 8601:2004 "extended" format standard
  (YYYY-MM-DDThh:mm:ssZ, for example, "1985-01-02T00:00:00Z").
  Also, to avoid time zone and daylight savings time confusion, time values are always converted to the UTC (GMT/Zulu) time zone.
  This makes it easy to specify time constraints in requests without having to worry about the time format (a nightmarish realm of possible formats and time zones).
  And this makes the results from different data sources easy to compare.
   
• Custom Graphs and Maps - ERDDAP gives you the ability to make customized graphs and maps. (See the Make A Graph option for each dataset.)

To see ERDDAP and UAF in action, watch the first half of this video.

Find out more about ERDDAP.

Start Using ERDDAP:
    Search for Interesting Datasets

• View a List of All 9,002 Datasets

• Do a Full Text Search for Datasets

  Search

• Search for Datasets by Category

  Datasets can be categorized in different ways by the values of various metadata attributes. Click on an attribute (cdm_data_type, institution, ioos_category, keywords, long_name, standard_name, variableName) to see a list of categories (values) for that attribute. Then, you can click on a category to see a list of relevant datasets.

• Search for Datasets with Advanced Search

• Search for Datasets by Protocol

  Protocols are the standards which specify how to request data.
  Different protocols are appropriate for different types of data and for different client applications.
   

  Protocol	Description
  griddap datasets	Griddap lets you use the OPeNDAP hyperslab protocol to request data subsets, graphs, and maps from gridded datasets (for example, satellite data and climate model data). griddap documentation
  tabledap datasets	Tabledap lets you use the OPeNDAP constraint/selection protocol to request data subsets, graphs, and maps from tabular datasets (for example, buoy data). tabledap documentation
  WMS datasets	The Web Map Service (WMS) lets you request an image with data plotted on a map. WMS documentation

   

• Developers of computer programs and JavaScripted web pages can search for datasets via

  • ERDDAP's RESTful search services
  • OpenSearch 1.1

Converters
In addition to serving data, ERDDAP has some handy converters:

• Convert a FIPS County Code to/from a County Name
• Convert a CF Standard Name to/from a GCMD Science Keyword
• Convert a Numeric Time to/from a String Time
• Convert UDUNITS to/from Unified Code for Units of Measure (UCUM)

Metadata
ERDDAP has Web Accessible Folders (WAF) with FGDC (?) and ISO 19115-2/19139 (?) .xml metadata files for all of the geospatial datasets.

RESTful Web Services
You can bypass ERDDAP's web pages and use ERDDAP's RESTful web services (for example, for searching for datasets, for downloading data, for making maps) directly from any computer program (for example, Matlab, R, or a program that you write) and even from web pages (via HTML image tags or JavaScript). documentation