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Overview

What are web services and why would you use them?

A definition provided by the Australian National Data Service is:

"Services in the research domain support the use of research collections and datasets by providing automated functions for the creation, access, processing and analysis of data."

Typically web services provide machine readable information that can be used by software to access data.  In many instances the end users would not be accessing the services in their web browser.

Services Tab - How to access services

If the maintainer of the collection has added links to web services, they will appear on this tab.

A Data Access Portal (DAP) collection may have files, services, or both listed.

The web services listed are hosted externally to the DAP (i.e. maintained on different systems), so it's possible they will differ from any files that are made available via the DAP.

Typically web services provide machine readable information that can be used by software to access data.  In many instances you would not be accessing the services in your web browser.  If you follow the URL in your browser it may look like the service is not working, but it may also be that it is intended to be used with different software.  You can find contact details on the "Description" tab of the collection, and sometimes there will be contact details in the description of the service itself.


Viewing details of the services

Click on the arrow (i.e. the triangle shape) on the left side of the service listing.

A table should expand to display more detail about the service.  The details provided will depend on the type of service.  If the details contain contact information you can use this to find out more about the particular service.  If not, check the "Description" tab of the DAP collection for contact details.

Types of services

There are many types of services that can be linked to, and the specific nature of what the services do will vary depending on the research domain and the type of data or software that the service provides.

Generic

This type could contain a URL for any service.  If it's not clear how you should use the service, or what software you should use, check to see if any contact details are provided.  If none are provided in the information about the service, check the Description tab of the collection for the contact details there.

OGC_WMS

Open Geospatial Consortium Web Map Service.  This type of service can be used with GIS software (e.g. QGIS), or specially designed websites.  Mapping services typically provide visualisation of maps but do not allow the user the download raw data.  You can copy the URL and use it with your GIS software.  Note that if you follow the link in your web browser you will see an error message.  This is normal, and is because the URL by itself does not contain any queries for the web service.  These queries are added by your GIS software when accessing the service.

OGC_WCS

Open Geospatial Consortium Web Coverage Service.  This type of service provides geospatial data and can be used with GIS software (e.g. QGIS), or specially designed websites.  Coverage services typically allow the user to download data in a raster format.  You can copy the URL and use it with your GIS software.  Note that if you follow the link in your web browser you will see an error message.  This is normal, and is because the URL by itself does not contain any queries for the web service.  These queries are added by your GIS software when accessing the service.

OGC_WFS

Open Geospatial Consortium Web Feature Service.  This type of service provides geospatial data and can be used with GIS software (e.g. QGIS), or specially designed websites.  Feature services typically allow the user to download data in a vector format.  You can copy the URL and use it with your GIS software.  Note that if you follow the link in your web browser you will see an error message.  This is normal, and is because the URL by itself does not contain any queries for the web service.  These queries are added by your GIS software when accessing the service.

Example - using services

Given the variety of web services that exist, a comprehensive list of examples is not possible.  This example will use the OGC_WMS service listed for the Soil and Landscape Grid National Soil Attribute Maps - Bulk Density - Whole Earth (3" resolution) - Release 1 (http://doi.org/10.4225/08/546EE212B0048) and the AuScope geospatial portal (http://portal.auscope.org/).

Open the to find the DAP collection, then click on the "Services" tab.

Find the "OGC_WMS" service URL.  Copy the URL, but don't follow the link in your browser.

Now open .

In the "Layers" panel, click on the "Custom" tab.

Paste the OGC_WMS URL you copied into the "WSM Url" input box and then click the search button (the magnifying glass icon).

The portal will retrieve a list of layers you can add.  Expand the options for one of them by clicking the arrow icon for it, then click "Add layer to Map"

The portal will open the layer and present it.

You can now select the region you are interested in, without needing to download all the data first.  Similar features should be available in your GIS software.


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