THREDDS Data Server 4.6
Overview
The THREDDS Data Server (TDS) is a web server that provides metadata
and data access for scientific datasets, using OPeNDAP, OGC WMS and
WCS, HTTP, and other remote data access protocols. The TDS is developed and
supported by Unidata, a division of the University Corporation for
Atmospheric Research (UCAR), and is sponsored by the National Science Foundation.
Some of the technology in the TDS:
- THREDDS Dataset Inventory Catalogs
are used to provide virtual directories of available data and their
associated metadata. These catalogs can be generated dynamically or
statically.
- The Netcdf-Java/CDM library
reads NetCDF, OpenDAP, and HDF5 datasets, as well as other binary
formats such as GRIB and NEXRAD into a Common Data Model (CDM),
essentially an (extended) netCDF view of the data. Datasets that can be
read through the Netcdf-Java library are called CDM datasets.
- TDS can use the NetCDF Markup Language (NcML) to modify and create virtual aggregations of
CDM datasets.
- An integrated server provides OPeNDAP access to any CDM dataset. OPeNDAP is a widely used, subsetting data access
method extending the HTTP protocol.
- An integrated server provides bulk file access through the HTTP protocol.
- An integrated server provides data access through the OpenGIS Consortium (OGC) Web Coverage Service
(WCS) protocol, for any "gridded" dataset whose coordinate system information is complete.
- An integrated server provides data access through the
OpenGIS Consortium (OGC) Web Map Service (WMS)
protocol, for any "gridded" dataset whose coordinate system information is complete. THREDDS integrates
a version of ncWMS and its companion
"Godiva" web application for WMS access and online visualization, developed
at the University of Reading.
- The integrated ncISO server provides automated metadata analysis and ISO metadata generation.
- The integrated NetCDF Subset Service allows subsetting certain CDM datasets
in coordinate space, using a REST API. Gridded data subsets can be returned in CF-compliant netCDF-3 or netCDF-4.
Point data subsets can be returned in CSV, XML, WaterML (with assistance
from ERDDAP [NOAA / Robert Simons/CoHort Software], license information),
or CF-DSG netCDF files.
The THREDDS Data Server is implemented in 100% Java*, and is
contained in a single war file, which allows very easy installation
into a servlet container
such as the open-source Tomcat
web server. Configuration is made as simple and as automatic as
possible, and we have made the server as secure as possible. The
library is freely available and the source code is released under the
(MIT-style) netCDF library license.
*Writing to netCDF-4 files is supported through the netCDF C library only.
Much of the realtime data available over the Unidata Internet Data Distribution (IDD) is
available through a THREDDS Data Server hosted at Unidata on thredds.ucar.edu.
You are welcome to browse and access these meteorological datasets. If
you need regular access to large amounts of data, please contact support-idd@unidata.ucar.edu.
System Requirements
- Java version 7
- Tomcat version 7.
- Be sure to keep up with the latest versions of Java and Tomcat for security fixes. This is required for publically accessible servers!
Downloads
TDS 4.6 is the stable release. It requires Tomcat 7+ and Java 8+.
TDS Services
Standard TDS Services
Experimental TDS Services
Other ways to use TDS
Other Documentation
This document was last updated November 2018