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.
This particular ERDDAP installation has oceanographic data
(for example, data from satellites and buoys).
Easier Access to Scientific Data
Our focus is on making it easier for you to get scientific data.
Different scientific communities have developed different types of data servers,
for example, OPeNDAP, WCS, SOS, OBIS, and web pages. Each is great on its own.
But without ERDDAP, it is difficult to get data from different types of servers:
- Different data servers make you format your data request in different ways.
- Different data servers return data in different formats, usually not the common file format that you want.
- Different datasets use different formats for time data, so the results are hard to compare.
ERDDAP unifies the different types of data servers
so you have a consistent way to get the data you want, in the format you want.
- ERDDAP acts as a middleman between you and various remote data servers.
When you request data from ERDDAP,
ERDDAP reformats the request into the format required by the remote server,
sends the request to the remote server, gets the data, reformats the data, and sends the data to you.
You no longer have to go to different data servers to get data from different datasets.
- ERDDAP offers an easy-to-use, consistent way to request data: via the OPeNDAP standard.
Many datasets can also be accessed via the Web Map Service (WMS).
- ERDDAP returns data in the common file format of your choice.
For example, .html table, ESRI .asc and .csv, Google Earth .kml, OPeNDAP binary,
.mat, .nc, ODV .txt, .csv, .tsv, .json, and .xhtml.
- ERDDAP can also return a .png or .pdf image with a customized graph or map.
- ERDDAP standardizes the dates+times in the results.
Data from other data servers is hard to compare
because the dates+times often are expressed in different formats
(for example, "Jan 2, 1985", 2 Jan 85, 02-JAN-1985, 1/2/85, 2/1/85,
1985-01-02, "days since Jan 1, 1900").
For string times, ERDDAP always uses the ISO 8601 standard format, for example, 1985-01-02T00:00:00Z.
For numeric times, ERDDAP always uses "seconds since 1970-01-01T00:00:00Z".
ERDDAP always uses the UTC (GMT, Zulu) time zone to remove the difficulties
of working with different time zones and standard time vs. daylight saving time.
- ERDDAP has web pages (for humans with browsers) and web services (for computer programs).
ERDDAP's RESTful web services let anyone build other web applications (with web pages)
and web services on top of ERDDAP.
For a quick introduction to ERDDAP,
watch the first half of this
video. (5 minutes)
In it, a scientist downloads ocean currents forecast data from ERDDAP to model a toxic
spill in the ocean using
NOAA's GNOME software (in 5 minutes!).
Thanks to Rich Signell. (One tiny error in the video:
when searching for datasets, don't use AND between search terms. It is implicit.)
Find out more about ERDDAP.
Data Providers: You can
set up your own ERDDAP server
and serve your own data.
The small effort to set up ERDDAP brings many benefits.
If you already have a web service for distributing your data,
you can set up ERDDAP to access your data via the existing service
or via the source files or database.
Then, people will have another way to access your data
and will be able to download the data in additional file formats
or as graphs or maps.
Datasets can be categorized in different ways by the values of various metadata attributes.
Click on an attribute
standard_name) 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 by Protocol
Protocols are the standards which define how to request data.
Different protocols are appropriate for different types of data and for different client applications.
Click on a protocol to see a list of datasets which are available via that protocol in ERDDAP.
||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).
||Tabledap lets you use the OPeNDAP constraint protocol to request data subsets, graphs, and maps from tabular datasets (for example, buoy data).
||The Web Map Service (WMS) lets you request an image with data plotted on a map.