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2.6 Other layer metadata

The OneGeology Portal client will harvest the following information from each WMS layer.

Note, the indicative XPATH in the below tables relates to the GetCapabilities response document

Metadata name Indicative XPATH to metadata
(WMS version is shown in brackets)
name /WMT_MS_Capabilities/Capability/Layer/Layer/Name (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/Name (1.3.0)
As already detailed above

2 star accreditation requirement

For a 2 star accredited service, each OneGeology layer name should conform to the naming protocols.

title /WMT_MS_Capabilities/Capability/Layer/Layer/Title (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/Title (1.3.0)
As already detailed above.

2 star accreditation requirement

For a 2 star accredited service, each OneGeology layer title must conform to the naming protocols.

abstract /WMT_MS_Capabilities/Capability/Layer/Layer/Abstract (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/Abstract (1.3.0)
You must provide a description of your layer data. You may wish to include other metadata, such as
information about your organization and other data you make available. You may also wish to include a
statement on access constraints.

2 star accreditation requirement

For a 2 star accredited service, ALL OneGeology layers must provide a descriptive abstract for all their OneGeology layers.

keywords
(and short phrases)
/WMT_MS_Capabilities/Capability/Layer/Layer/KeywordList/Keyword (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/KeywordList/Keyword (1.3.0)

The Keyword "OneGeology" must be present to be able to search for services and layers with this
keyword. OneGeologyEurope participants should also include relevant keywords chosen from
the keyword list created for that project and listed in Appendix I below. The main purpose of these
keywords is to make your services discoverable by a user searching in a catalogue of services, so a
clearly formed but limited list of geosciences domain specific is ideal and all OneGeology global
participants may also want to consider using items from this proposed OneGeology-Europe list, which
has been formed by looking at many such lists available around the world including the European GEMET
thesaurus found at: http://eionet.europa.eu/gemet/.

The following broad concepts are good starting points

http://eionet.europa.eu/gemet/concept?cp=2405 (earth science)

http://eionet.europa.eu/gemet/concept?cp=3648 (geological process)

Each keyword (or short phrase) must be contained within its own <keyword> element.

In addition to this we also require you to add a number of special ‘Cataloguing keywords’ to help the
OneGeology Portal and catalogue services better index your layers. These special keywords have a term then an ‘@’
symbol and then your value for the term, as below:

*Continent:                          continent@value       Required
*Subcontinent:                       subcontinent@value    Conditional
*Geographic area (usually country):  geographicarea@value  Required
*State(Region or province):          subarea@value         Conditional
*Data provider:                      dataprovider@value    Required
*Service provider:                   serviceprovider@value Required

The geographicarea@value represents a verbalization of the code that starts a layer name. For most
layers geographicarea@value will be a country; this INCLUDES layers that only show a sub-region or
state within a country.

The values for Continent, Subcontinent and Country must be taken from the United Nations (UN) list:
http://unstats.un.org/unsd/methods/m49/m49regin.htm used by the OneGeology Portal.

Conditional keywords are required if they apply.
Eg. If the geographic area is a state or province then the subarea keyword is required.

2 star accreditation requirement

For a 2 star accredited service, ALL OneGeology layers must include the
‘OneGeology’ keyword and all appropriate ‘Cataloguing keywords’.

In addition we would like that you also supply the following two special ‘Metadata keywords’ for each
layer. These keywords help make the GetCapabilities response ISO19115 core compliant.

*Layer (Data set) date:              DS_DATE@value         
*Layer (Data set) topic category:    DS_TOPIC@value        (one or more as appropriate)

The topic category is taken from the ISO 19119 topic category listing. A good reference to the
categories and what they represent is found at: http://gcmd.nasa.gov/User/difguide/iso_topics.html.
We anticipate that most layers would have a DS_TOPIC@geoscientificinformation keyword.

3 star accreditation requirement

For a 3 star accredited service, ALL OneGeology layers must include all appropriate ‘Metadata keywords’.

So for example, the layer “AFG AGS 1:1M Bedrock Age” would include the following keywords:

<KeywordList>
<Keyword>OneGeology</Keyword>
<Keyword>geology</Keyword>
<Keyword>Afghanistan</Keyword>
<Keyword>continent@Asia</Keyword>
<Keyword>subcontinent@South-central Asia</Keyword>
<Keyword>geographicarea@Afghanistan</Keyword>
<Keyword>serviceprovider@British Geological Survey</Keyword>
<Keyword>dataprovider@Afghanistan Geological Survey</Keyword>
<Keyword>DS_TOPIC@geoscientificinformation</Keyword>
<Keyword>DS_DATE@2008-12-03</Keyword>
</KeywordList>

Note, that we have the country twice, once as one of the OneGeology Portal special keywords, and
once as the country only; this is because we recognize that the service may be consumed (and
catalogued) by services other than OneGeology. We don’t include a subarea@ keyword in this list
because that would not be appropriate in this instance.

Extent /WMT_MS_Capabilities/Capability/Layer/Layer/LatLonBoundingBox (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/EX_GeographicBoundingBox (1.3.0)

In WMS version 1.1.1 a comma separated list of (latitude-longitude decimal degree) coordinates defining an imaginary box that entirely encompasses the map data. It is always specified as minimum-X, minimum-Y, maximum-X, and maximum-Y.

In WMS version 1.3.0 four elements each describing a single bounding limit (always in the order: west, east, south, north)

2 star accreditation requirement

For a 2 star accredited service ALL OneGeology layers must supply a LatLonBoundingBox defined using SRS EPSG:4326 WGS1984 latitude/longitude.

Reference System
Spatial (1.1.1) or
Coordinate (1.3.0)
/WMT_MS_Capabilities/Capability/Layer/Layer/SRS (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/CRS (1.3.0)

A list of one or more horizontal ’ Spatial Reference Systems’ that the layer can handle (will accept
requests in and return results based upon those SRS). In WMS 1.1.1, the returned image is always
projected using a pseudo-Plate Carrée projection that plots Longitude along the X-axis and
Latitude along the Y-axis.

For example, the exemplar service lists the following Spatial Reference Systems:
EPSG:4326, EPSG:3857, CRS:84, EPSG:27700, EPSG:4258

2 star accreditation requirement

For a 2 star accredited service ALL OneGeology layers must support EPSG:4326.

Each layer must supply a list of the SRS it supports

We would like too if the layers also support Spherical Mercator projection
(EPSG:3857), so that they can be used in various online mapping
applications, such as OpenLayers and Google Maps.

BoundingBox /WMT_MS_Capabilities/Capability/Layer/Layer/BoundingBox (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/BoundingBox (1.3.0)

The BoundingBox attributes indicate the edges of the bounding box in units of the specified spatial
reference system, for example, the exemplar service provides the following BoundingBox information for
the GBR BGS 1:625k bedrock lithology layer:

Example WMS 1.1.1 response

<BoundingBox SRS=“EPSG:4326” minx=“-8.64846” miny=“49.8638” maxx=“1.76767” maxy=“60.8612” />
<BoundingBox SRS=“EPSG:3857” minx=“-962742” miny=“6.42272e+006” maxx=“196776” maxy=“8.59402e+006” />
<BoundingBox SRS=“CRS:84” minx=“-8.64846” miny=“49.8638” maxx=“1.76767” maxy=“60.8612” />
<BoundingBox SRS=“EPSG:27700” minx=“-77556.4” miny=“-4051.91” maxx=“670851” maxy=“1.23813e+006” />
<BoundingBox SRS=“EPSG:4258” minx=“-8.64846” miny=“49.8638” maxx=“1.76767” maxy=“60.8612” />

Example WMS 1.3.0 response

<BoundingBox CRS=“EPSG:4326” minx=“49.8638” miny=“-8.64846” maxx=“60.8612” maxy=“1.76767” />
<BoundingBox CRS=“EPSG:3857” minx=“-962742” miny=“6.42272e+006” maxx=“196776” maxy=“8.59402e+006” />
<BoundingBox CRS=“CRS:84” minx=“-8.64846” miny=“49.8638” maxx=“1.76767” maxy=“60.8612” />
<BoundingBox CRS=“EPSG:27700” minx=“-77556.4” miny=“-4051.91” maxx=“670851” maxy=“1.23813e+006” />
<BoundingBox CRS=“EPSG:4258” minx=“49.8638” miny=“-8.64846” maxx=“60.8612” maxy=“1.76767” />

Please note the swap in x,y axes order for the geographic coordinate systems EPSG:4258 and
EPSG:4326 between WMS versions. In WMS version 1.3.0 the x-axis is the first axis in the CRS
definition, and the y-axis is the second. EPSG geographic coordinate reference systems follow
ISO 6709 and ALWAYS list latitude before longitude.

2 star accreditation requirement

For a 2 star accredited service ALL OneGeology layers must supply an EPSG:4326 BoundingBox

DataURL (optional) /WMT_MS_Capabilities/Capability/Layer/Layer/DataURL (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/DataURL (1.3.0)

This may be used to provide further information about all the digital data offered by the data provider,
though it is primarily used to provide a link to non-standards compliant metadata for the layer in question.

<DataURL>
<Format>text/html</Format>
<OnlineResource
  xmlns:xlink=“http://www.w3.org/1999/xlink”
  xlink:type=“simple”
  xlink:href=“http://www.bgs.ac.uk/discoverymetadata/13480426.html“ />
</DataURL>

MetadataURL /WMT_MS_Capabilities/Capability/Layer/Layer/MetadataURL (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/MetadataURL (1.3.0)

You should supply one or more on-line resources offering detailed, standardized (either as "FGDC:1998"
or "ISO 19115:2003") metadata about the layer data. If your metadata is not available in either of these standards you MUST instead use a DataURL.

The core ISO 19115:2003 metadata required to be compliant is shown in Section 2.7. Note, there are no formatting requirements; this information could be provided as xml or html or text or pdf etc as long as it accessible on the web.

Example WMS 1.1.1 response

<MetadataURL type=“TC211”>
<Format>application/xml; charset=UTF-8</Format>
<OnlineResource
  xmlns:xlink=“http://www.w3.org/1999/xlink”
  xlink:type=“simple”
  xlink:href=“http://metadata.bgs.ac.uk/geonetwork/srv/en/csw?
    service=CSW&
    version=2.0.2&
    request=GetRecordById&
    id=ac9f8250-3ae5-49e5-9818-d14264a4fda4&” />
</MetadataURL>

Example WMS 1.3.0 response

<MetadataURL type=“ISO 19115:2003”>
<Format>application/xml; charset=UTF-8</Format>
<OnlineResource
  xmlns:xlink=“http://www.w3.org/1999/xlink”
  xlink:type=“simple”
  xlink:href=“http://metadata.bgs.ac.uk/geonetwork/srv/en/csw?
    service=CSW&
    version=2.0.2&
    request=GetRecordById&
    id=ac9f8250-3ae5-49e5-9818-d14264a4fda4&” />
</MetadataURL>

Please note: the defined attribute value to indicate ISO 19115:2003 metadata is “ISO 19115:2003” in
WMS version 1.3.0 as opposed to “TC211” in version 1.1.1. In version 1.3.0, communities may ALSO
define their own attributes. We RECOMMEND that if you can change this attribute for different WMS
version GetCapabilities responses you should use “ISO 19115:2003” for your WMS 1.3.0 response.
If you can only configure one response type then you MUST use “TC211”.

2 star accreditation requirement

For a 2 star accredited service, any MetadataURL supplied must link to a valid metadata resource for that layer.

4 star accreditation requirement

For a 4 star accredited service, ALL OneGeology layers and feature types
(WMS and WFS) must supply a MetadataURL to a valid metadata resource
for that layer (and feature type), which conforms at least to the
OneGeology metadata profile.

Minimum Scale /WMT_MS_Capabilities/Capability/Layer/Layer/ScaleHint@min (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/MinScaleDenominator (1.3.0)

A hint to the minimum scale at which the map will not be zoomed in beyond. This is cited in units
relating to the diagonal dimension of the screen in units relevant to the software providing the service,
and would normally be populated automatically by the software.

Maximum Scale /WMT_MS_Capabilities/Capability/Layer/Layer/ScaleHint@max (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/MaxScaleDenominator (1.3.0)

A hint to the maximum scale at which the map will not be zoomed out beyond. This is cited in units
relating to the diagonal dimension of the screen in units relevant to the software providing the service,
and would normally be populated automatically by the software.

Is the layer queryable /WMT_MS_Capabilities/Capability/Layer/Layer@queryable (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/@queryable (1.3.0)
Parameter to indicate whether a GetFeatureInfo request is allowed on the layer

3 star accreditation requirement

For a 3 star accredited service ALL OneGeology layers must provide a valid
GetFeatureInfo response. At a minimum, the GetFeatureInfo response must support text/html.

Legend url /WMT_MS_Capabilities/Capability/Layer/Layer/Style/LegendURL (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/Style/LegendURL (1.3.0)

We require you to have some sort of legend to accompany your map data. If you are using the latest
version of MapServer server, this will be created for you automatically using the inbuilt SLD capability.
If your WMS server is not SLD capable, or if you have a complex legend, you may add the LegendURL
manually in your GetCapabilities response document. See below section 2.6.1 style examples.

2 star accreditation requirement

For a 2 star accredited service, ALL OneGeology layers must supply a readable legend graphic.

Style name /WMT_MS_Capabilities/Capability/Layer/Layer/Style/Name (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/Style/Name (1.3.0)
Computer readable name for the style. If you have only one style this would normally be given the name
‘default’. See below section 2.6.1 style examples.
Style title /WMT_MS_Capabilities/Capability/Layer/Layer/Style/Title (1.1.1)
/WMS_Capabilities/Capability/Layer/Layer/Style/Title (1.3.0)
Human readable title for the style. See below section 2.6.1 style examples.

Section last modified: 27 June 2013

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