TDS Services

Data Services

Standard Data Services

The TDS has a set of Standard Data Services that are always available (unless explicitly disabled) and can be referenced from any configuration catalog:

• cdmRemote
• dap4
• httpService
• resolver
• netcdfSubsetGrid
• netcdfSubsetPoint
• opendap
• wcs
• wms

Available Services

The TDS configures the appropriate set of standard data services for each dataType/featureType. You can configure the available data services globally, and they will be applied to all datasets of that dataType/featureType. If you do not specify a service for a dataset, but you do specify its dataType/featureType, then the datatype-appropriate services will be enabled for it.

User-Defined Services

You can still define your own services, either globally in the root catalog, or locally in any configuration catalog.

• Services placed in the root catalog are global and can be referenced in any other config catalog.
• Services placed in any other catalog are local, are used only in that catalog, and override (by name) any global services.

Server Information Services

Server Information Services provide human- and machine-readable access to information about the server installation. E.g., an abstract and a list of keywords summarizing the services and data available on the server, contact information and other information about the group hosting the server, and the version of the THREDDS Data Server (TDS) running.

Basic Configuration:

Catalog Services

Catalog Services provide subsetting and HTML conversion services for THREDDS catalogs. Catalogs served by the TDS can be subset and/or viewed as HTML. Remote catalogs, if allowed/enabled, can be validated, displayed as HTML, or subset.

Basic Configuration:

ncISO Metadata Services

The ncISO plugin adds the ncISO Metadata Services, which facilitate the generation of ISO 19115 metadata representation from data in NetCDF.

The three ncISO Metadata Services are:

• ISO

  The ISO Metadata Service provides ISO 19115 metadata representation of a dataset’s structure and metadata.

• NCML

  The NCML Metadata Service provides NCML representation of a dataset.

  Note: More details are available about how to Use NcML in the TDS.

• UDDC

  Provide an evaluation of how well the metadata contained in a dataset conforms to the NetCDF Attribute Convention for Data Discovery (NACDD).

Basic Configuration:

Catalog Service Configuration:

(These are the exact required values to enable these service.)

Data Access Services

The TDS provides a number of different Data Access Services, including:

• OPeNDAP

  The OPeNDAP DAP2 data access protocol.

  Note: View all the available configuration options for OPeNDAP in the TDS.

• NetCDF Subset Service

  The NetCDF Subset Service (NCSS) is a web service for subsetting CDM scientific datasets.

  Note: Set NCSS configuration options in the TDS Configuration File (threddsConfig.xml).

• CDM Remote

  The cdmremote/ncstream data access service is automatically enabled when an appropriate FeatureCollection is used.

• OGC Web Coverage Service (WCS)

  OGC Web Coverage Service (WCS) supports access to geospatial data as “coverages”.

  Note: More setup, configuration, and implementation details for the TDS OGC WCS implementation are available in the TDS WCS Reference.

• OGC Web Map Service (WMS)

  The OGC Web Map Service (WMS) supports access to geo-registered map images from geoscience datasets.

  Note: More setup, configuration, and implementation details for the TDS OGC WMS implementation are available in the TDS WMS Reference.

• HTTP File Download

  The HTTP File Download service supports HTTP byte ranges.

  Note: Set HTTP File Download configuration options in the TDS Configuration File (threddsConfig.xml).

• OGC Sensor Observation Service (SOS)

  The Sensor Observation Service (SOS) standard is applicable to use cases in which sensor data needs to be managed in an interoperable way.

  Note: The NcSOS plugin adds a OGC SOS service to your existing THREDDS server. (This plugin is maintained by the developers at Applied Science Associates.)

Basic Configuration:

Catalog Service Configuration:

(These are the exact required values to enable these service.)

TDS Requirements For THREDDS Catalog service Elements

Since the TDS provides data access services at predefined URL base paths, services whose access is listed as a THREDDS Catalog service element:

1. must use the appropriate value for the serviceType attribute;
2. must use the appropriate value for the service base URL attribute; and
3. may use any value (unique to the catalog) for the service name attribute

Examples of All Individual Services

The serviceType and base values are required in the following examples:

OPeNDAP

  <service name="odap" serviceType="OPeNDAP" base="/thredds/dodsC/"/>

NetCDF Subset Service

For Feature Type GRID, use:

<service name="ncssGrid" serviceType="NetcdfSubset" base="/thredds/ncss/grid/" />

For Feature Types POINT or STATION, use:

<service name="ncssPoint" serviceType="NetcdfSubset" base="/thredds/ncss/point/" />

WCS

  <service name="wcs" serviceType="WCS" base="/thredds/wcs/"/>

WMS

  <service name="wms" serviceType="WMS" base="/thredds/wms/" />

HTTP Bulk File Service

  <service name="fileServer" serviceType="HTTPServer" base="/thredds/fileServer/" />

ncISO

  <service name="iso" serviceType="ISO" base="/thredds/iso/" />

  <service name="ncml" serviceType="NCML" base="/thredds/ncml/" />

  <service name="uddc" serviceType="UDDC" base="/thredds/uddc/" />

SOS

  <service name="sos" serviceType="SOS" base="/thredds/sos/" />

Compound service Element Example

<service name="all" serviceType="Compound" base="">
  <service name="HTTPServer" serviceType="HTTPServer" base="/thredds/fileServer/"/>
  <service name="opendap" serviceType="OPENDAP" base="/thredds/dodsC/"/>
  <service name="ncssGrid" serviceType="NetcdfSubset" base="/thredds/ncss/grid/"/>
  <service name="cdmremote" serviceType="CdmRemote" base="/thredds/cdmremote/"/>

  <service name="wcs" serviceType="WCS" base="/thredds/wcs/"/>
  <service name="wms" serviceType="WMS" base="/thredds/wms/"/>

  <service name="iso" serviceType="ISO" base="/thredds/iso/"/>
  <service name="ncml" serviceType="NCML" base="/thredds/ncml/"/>
  <service name="uddc" serviceType="UDDC" base="/thredds/uddc/"/>

  <service name="sos" serviceType="SOS" base="/thredds/sos/"/>
</service>