Difference between revisions of "Attribute Convention for Data Discovery 2.0"

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        <font color="red">'''DRAFT - Not ready for use'''</font>
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RESERVED FOR FUTURE VERSION.
== Version and Status ==
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The most recent version (still in draft) is [[Attribute_Convention_for_Data_Discovery_1.3|ACDD 1.3]]
This version is designated as Version 2.0
 
This page always has the current version of the Attribute Convention for Data Discovery (ACDD). As it is updated, the version number at the top of the page will be updated.
 
 
 
See the [[http://wiki.esipfed.org/index.php/Category:Attribute_Conventions_Dataset_Discovery category page]] for information on the history of this convention.
 
 
 
=== Development ===
 
 
 
Any development version of the ACDD definitions is maintained at [[Attribute_Convention_for_Data_Discovery_(ACDD)_Working]].
 
 
 
= Overview =
 
This document describes attributes recommended for describing a NetCDF dataset to discovery systems such as Digital Libraries. THREDDS and other tools can use these attributes for extracting metadata from datasets, and exporting to Dublin Core, DIF, ADN, FGDC, ISO 19115 and other metadata formats. This will help systems and users locate and use data efficiently.
 
 
 
== Alignment with NetCDF and CF Conventions ==
 
The NetCDF User Guide [http://www.unidata.ucar.edu/software/netcdf/docs/netcdf.html (NUG)] provides basic recommendations for creating NetCDF files; the NetCDF Climate and Forecast Metadata Conventions [http://cf-pcmdi.llnl.gov/documents/cf-conventions/latest-cf-conventions-document-1/ (CF)]  provides more specific guidance. The ACDD builds upon and is compatible with these conventions; it may refine the definition of some terms in those conventions, but does not preclude the use of any attributes defined by the NUG or CF.
 
 
 
The NUG does not require any global attributes, though it recommends and defines two, title and history; CF specifies many more. ACDD 2.0 adopts all CF 1.6 global attributes with the exception of 'institution'; we specify 'creator_institution' and 'publisher_institution', to provide more provenance information. We also modify the syntax of the 'Conventions' attribute; we adopt the NUG recommendation to supply all conventions in a single attribute. This change has been approved by the CF Conventions Committee and will be part of CF 1.7, which is not yet published.
 
 
 
== Attribute Crosswalks ==
 
Many of these attributes correspond to general discovery metadata content, so they are available in many metadata standards. This [[Attribute_Convention_for_Data_Discovery_(ACDD)_Mappings]] page includes a crosswalk to THREDDS, OGC CSW, ISO 19115-2 and Rubric Categories.
 
 
 
== Additional Metadata: metadata_link attribute ==
 
The netCDF metadata model is focused on providing "use metadata" for the data included in the file (or granule). Other metadata dialects (i.e. ISO 19115) can provide information about collections and more details about the dataset. If additional metadata exists, you can make users aware of it by adding a global attribute named "metadata_link" to the netCDF file. The value of this attribute is a URL that gives the location of the more complete metadata.
 
 
 
== Maintenance of Metadata ==
 
 
 
ACDD attributes, like all NetCDF attributes, characterize their containing (parent) granules. As NetCDF data are processed (e.g., through subsetting or other algorithms), these characteristics can be altered. The software or user processor is responsible to update these attributes as part of the processing, but some software processes and user practices leave them unchanged. This affects both consumers and producers of these files, which comprises three roles:
 
* developers of software tools that process NetCDF files;
 
* users that create new NetCDF files from existing ones; and
 
* end users of NetCDF files.
 
 
 
NetCDF file ''creators'' (the first two roles) should ensure that the attributes of output files accurately represent those files, and specifically should not "pass through" any source attribute in unaltered form, unless it is known to remain accurate. NetCDF file ''users'' (all three roles) should verify critical attribute values, and understand how the source data and metadata were generated, to be confident the source metadata is current.
 
 
 
The ACDD geospatiotemporal attributes present a special case, as this information is already fully defined by the CF coordinate variables (the redundant attributes are recommended to simplify access).  Errors in these attributes will create an inconsistency between the metadata and data of the granule or file.  The risk of these 'inconsistency errors' is highest for files that are aggregated into longer or larger products, or subset into shorter or smaller products, such as files from numerical forecast models and gridded satellite observations. For this reason, some providers of those data types may choose to omit the ACDD geospatiotemporal attributes from their files. If the ACDD geospatiotemporal attributes are present, checking them against the CF coordinate variables can serve as a partial test of the metadata's validity.
 
 
 
<!--''{(Not for inclusion in final draft) As a working tool, the page [[NetCDF Utilities Metadata Handling]] has been created to identify the state of play for how tools handle metadata attributes when processing files.}''-->
 
 
 
= Global Attributes = 
 
== Highly Recommended ==
 
        <table width="95%" border="1" cellpadding="2" cellspacing="2">
 
            <tr>
 
                <th valign="top" width="200px">Attribute</th>
 
                <th valign="top">Description</th>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#title_Attribute title]
 
                </td>
 
                <td valign="top">A short phrase or sentence describing the dataset; this is a NetCDF Users Guide ([http://www.unidata.ucar.edu/software/netcdf/docs/netcdf.html#Attribute-Conventions NUG]) attribute.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#summary_Attribute summary]
 
                </td>
 
                <td valign="top">A paragraph describing the dataset, analogous to an abstract for a paper.</td>               
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#keywords_Attribute keywords]
 
                </td>
 
                <td valign="top">A comma-separated list of key words and/or phrases. Keywords may be common words or phrases, terms from a controlled vocabulary (GCMD is often used), or URIs for terms from a controlled vocabulary (see also keywords_vocabulary attribute).</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">Conventions</td>
 
                <td valign="top">A list of the conventions followed by the dataset; blank space separated is recommended but commas should be used if any convention name contains blanks. For files that comply with this version of ACDD, include the term ACDD-1.2. This attribute is  [http://www.unidata.ucar.edu/software/netcdf/docs/netcdf.html#Attribute-Conventions defined in NUG].</td>
 
            </tr>
 
        </table>
 
 
 
==Recommended==
 
<table width="95%" border="1" cellpadding="2" cellspacing="2">
 
            <tr>
 
                <th valign="top" width="200px">Attribute</th>
 
                <th valign="top">Description</th>
 
                <!-- <th valign="top">THREDDS</th>
 
                <th valign="top">ISO 19115-2</th>
 
                <th valign="top">OGC CSW</th>
 
                <th valign="top">Rubric Category</th>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#id_Attribute id] </td>
 
                <td valign="top">An identifier for the data set, provided by and unique within its naming authority. The combination of the "naming authority" and the "id" should be globally unique, but the id can be globally unique by itself also. IDs can be URLs, URNs, DOIs, meaningful text strings, a local key, or any other unique string of characters. The id should not include blanks.</td>
 
                <!--<td rowspan="2" valign="top">dataset@id </td>
 
                <td rowspan="2" colspan="1" valign="top">/gmi:MI_Metadata/gmd:fileIdentifier/gco:CharacterString (O) </td>
 
                <td rowspan="2">Identifier</td>
 
                <td rowspan="2">Identifier</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#naming_authority_Attribute naming_authority] </td>
 
                <td valign="top">The organization that provides the initial id (see above) for the dataset. The naming authority should be uniquely specified by this attribute.</td>
 
                <!-- <td></td>
 
                <td></td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#keywords_vocabulary_Attribute keywords_vocabulary] </td>
 
                <td valign="top">If you are following a guideline for the words/phrases in your "keywords" attribute, put the name of that guideline here. </td>
 
                <!--<td valign="top">metadata/keyword@vocabulary</td>
 
                <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:descriptiveKeywords/gmd:MD_Keywords/gmd:thesaurusName/gmd:CI_Citation/gmd:title/gco:CharacterString </td>
 
                <td></td>
 
                <td>Text Search</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#cdm_data_type_Attribute cdm_data_type] </td>
 
                <td>The organization of the data, as derived from the Common Data Model's Scientific Data layer and understood by THREDDS (this is a [http://www.unidata.ucar.edu/projects/THREDDS/tech/catalog/InvCatalogSpec.html#dataType THREDDS "dataType"]). One of point, profile, section, station, station_profile, trajectory, grid, image, or swath. Please note that this is different from the CF NetCDF attribute 'featureType' that indicates a Discrete Sampling Geometry file - for guidance on those terms, please see [http://www.nodc.noaa.gov/data/formats/netcdf/ this NODC guidance].</td>
 
                <!-- <td valign="top">metadata/dataType</td>
 
                <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:spatialRepresentationType/gmd:MD_SpatialRepresentationTypeCode May need some extensions to this codelist. Current values: vector, grid, textTable, tin, stereoModel, video. </td>
 
                <td></td>
 
                <td>Other</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#history_Attribute history]</td>
 
                <td valign="top">Describes the processes/transformations used to create this data; can serve as an audit trail. This attribute is defined in the [http://www.unidata.ucar.edu/software/netcdf/docs/netcdf.html#Attribute-Conventions NUG]: 'This is a character array with a line for each invocation of a program that has modified the dataset. Well-behaved generic netCDF applications should append a line containing: date, time of day, user name, program name and command arguments.' To include a more complete description you can append an ISO Lineage reference; see [https://geo-ide.noaa.gov/wiki/index.php?title=ISO_Lineage NOAA EDM ISO Lineage guidance]. </td>
 
                <!--  <td valign="top">metadata/documentation[@type="history"]</td>
 
                <td valign="top">/gmi:MI_Metadata/gmd:dataQualityInfo/gmd:DQ_DataQuality/gmd:lineage/gmd:LI_Lineage/gmd:statement/gco:CharacterString (O)</td>
 
                <td></td>
 
                <td>Text Search</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">source</td>
 
                <td valign="top">The method of production of the original data. If it was model-generated, source should name the model and its version. If it is observational, source should characterize it. This attribute is [http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.6/cf-conventions.html#description-of-file-contents defined in CF].</td>
 
                <!-- <td valign="top"></td>
 
            <td valign="top"></td>
 
            <td></td>
 
            <td></td>-->
 
            </tr>
 
 
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#comment_Attribute comment] </td>
 
                <td valign="top"> Miscellaneous information about the data, not captured elsewhere. This attribute is [http://cf-pcmdi.llnl.gov/documents/cf-conventions/1.6/cf-conventions.html#description-of-file-contents defined in CF].</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">date_product_modified</td>
 
                <td valign="top">The date on which any of the provided content, including data, metadata, and presented format, was last created or changed (ISO 8601 format)</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">date_values_modified</td>
 
                <td valign="top">The date on which the provided data values were last created or changed; excludes metadata and formatting changes (ISO 8601 format)</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">creator</td>
 
                <td valign="top">The name of the person principally responsible for originating this data.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">creator_email</td>
 
                <td valign="top">The email address of the person principally responsible for originating this data.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher</td>
 
                <td valign="top">The person responsible for the data file or product, with its current metadata and format.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher_email</td>
 
                <td valign="top">The email address of the person responsible for the data file or product.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#processing_level_Attribute processing_level]</td>
 
                <td valign="top">A textual description of the processing (or quality control) level of the data.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#acknowledgement_Attribute acknowledgement]</td>
 
                <td valign="top">A place to acknowledge various type of support for the project that produced this data. </td>
 
            </tr>
 
            <tr>
 
                <td valign="top">geospatial_bounds</td>
 
                <td>Describes geospatial extent using any of the geometric objects (2D or 3D) supported by the [http://en.wikipedia.org/wiki/Well-known_text Well-Known Text] (WKT) format.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lat_min_Attribute geospatial_lat_min] </td>
 
                <td valign="top">Describes a simple lower latitude limit; may be part of a bounding box or cube. Geospatial_lat_min specifies the southernmost latitude covered by the dataset.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lat_max_Attribute geospatial_lat_max]</td>
 
                <td valign="top">Describes a simple upper latitude limit; may be part of a bounding box or cube. Geospatial_lat_max specifies the northernmost latitude covered by the dataset.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lon_min_Attribute geospatial_lon_min]</td>
 
                <td valign="top">Describes a simple longitude limit; may be part of a bounding box or cube. Geospatial_lon_min specifies the westernmost longitude covered by the dataset. Cases where geospatial_lon_min is greater than geospatial_lon_max indicate the bounding box extends from geospatial_lon_max, through the longitude range discontinuity meridian (either the antimeridian for -180:180 values, or Prime Meridian for 0:360 values), to geospatial_lon_min.</td>
 
                <!-- <td valign="top">metadata/geospatialCoverage/eastwest/start</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox/gmd:westBoundLongitude/gco:Decimal </td> <td>BoundingBox</td> <td>Extent</td> -->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lon_max_Attribute geospatial_lon_max]</td>
 
                <td valign="top">Describes a simple longitude limit; may be part of a bounding box or cube. Geospatial_lon_max specifies the easternmost longitude covered by the dataset. Cases where geospatial_lon_min is greater than geospatial_lon_max indicate the bounding box extends from geospatial_lon_max, through the longitude range discontinuity meridian (either the antimeridian for -180:180 values, or Prime Meridian for 0:360 values), to geospatial_lon_min.</td>
 
                <!-- <td valign="top">metadata/geospatialCoverage/eastwest/size</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:geographicElement/gmd:EX_GeographicBoundingBox/gmd:eastBoundLongitude/gco:Decimal </td> <td>BoundingBox</td> <td>Extent</td> -->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_vertical_min_Attribute geospatial_vertical_min] </td>
 
                <td valign="top">Describes a numerically smaller vertical limit; may be part of a bounding box or cube. If geospatial_vertical_positive is up ('altitude' orientation), the geospatial_vertical_min attribute specifies the location closest to the earth's center covered by the dataset. If geospatial_vertical_positive is down ('depth' orientation), the geospatial_vertical_min attribute specifies the location furthest from the earth's center covered by the dataset.</td>
 
                <!-- <td valign="top">metadata/geospatialCoverage/updown/start</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:verticalElement/gmd:EX_VerticalExtent/gmd:minimumValue/gco:Real</td> <td></td> <td>Extent</td> -->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_vertical_max_Attribute geospatial_vertical_max]</td>
 
                <td valign="top">Describes a numerically larger vertical limit; may be part of a bounding box or cube. If geospatial_vertical_positive is up ('altitude' orientation), the geospatial_vertical_min attribute specifies the location furthest from the earth's center covered by the dataset. If geospatial_vertical_positive is down ('depth' orientation), the geospatial_vertical_min attribute specifies the location closest to the earth's center covered by the dataset.</td>
 
                <!-- <td valign="top">metadata/geospatialCoverage/updown/size</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:verticalElement/gmd:EX_VerticalExtent/gmd:maximumValue/gco:Real</td> <td></td> <td>Extent</td> -->
 
            </tr>
 
            <tr>
 
                <td valign="top">geospatial_vertical_positive</td>
 
                <td valign="top">One of 'up' or 'down'. If up, vertical values are interpreted as 'altitude', with negative values corresponding to below the reference datum (e.g., under water). If down, vertical values are interpreted as 'depth', positive values correspond to below the reference datum.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#time_coverage_start_Attribute time_coverage_start]</td>
 
                <td valign="top">Describes the time of the first data point in the data set. ISO8601 format recommended.</td>
 
                <!--                <td valign="top">metadata/timeCoverage/start</td>
 
                <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/gmd:EX_TemporalExtent/gmd:extent/gml:TimePeriod/gml:beginPosition</td>
 
                <td></td>
 
                <td>Extent</td>
 
-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#time_coverage_end_Attribute time_coverage_end]</td>
 
                <td valign="top">Describes the time of the last data point in the data set. ISO8601 format recommended.</td>
 
                <!-- <td valign="top">metadata/timeCoverage/end</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/gmd:EX_TemporalExtent/gmd:extent/gml:TimePeriod/gml:endPosition</td> <td></td> <td>Extent</td> -->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#time_coverage_duration_Attribute time_coverage_duration]</td>
 
                <td valign="top">Describes the duration of the data set. ISO8601 duration format recommended.</td>
 
                <!--<td valign="top">metadata/timeCoverage/duration</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:temporalElement/gmd:EX_TemporalExtent/gmd:extent/gml:TimePeriod/gml:beginPosition provides an ISO8601 compliant description of the time period covered by the dataset. This standard supports descriptions of [http://en.wikipedia.org/wiki/ISO_8601#Durations durations].</td> <td></td> <td>Extent</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#time_coverage_resolution_Attribute time_coverage_resolution]</td>
 
                <td valign="top">Describes the targeted time period between each value in the data set. ISO8601 duration format recommended.</td>
 
                <!--<td valign="top">metadata/timeCoverage/resolution</td> <td></td> <td></td> <td>Extent</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/thredds/v4.3/netcdf-java/formats/DataDiscoveryAttConvention.html#license_Attribute license]</td>
 
                <td valign="top">Provide the URL to a standard or specific license, enter "Freely Distributed" or "None", or describe any restrictions to data access and distribution in free text.</td>
 
                <!-- <td valign="top">metadata/documentation[@type="rights"]</td> <td valign="top">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:resourceConstraints/gmd:MD_LegalConstraints/gmd:useLimitation/gco:CharacterString</td> <td></td> <td></td> -->
 
            </tr>
 
        </table>
 
 
 
==Suggested==
 
<table width="95%" border="1" cellpadding="2" cellspacing="2">
 
            <tr>
 
                <th valign="top" width="200px">Attribute</th>
 
                <th valign="top">Description</th>
 
                <!--                <th valign="top">THREDDS</th>
 
                <th valign="top">ISO 19115-2</th>
 
                <th valign="top">OGC CSW</th>
 
                <th valign="top">Rubric Category</th>
 
-->
 
            </tr>
 
            <tr>
 
                <td valign="top">contributor_info</td>
 
                <td valign="top">The name and role of any individuals, projects, or institutions that contributed to the creation of this data. May be presented as free text, or in a structured format compatible with conversion to ncML (e.g., insensitive to whitespace).</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">date_product_available</td>
 
                <td valign="top">The date on which this data file or product was produced or distributed (ISO 8601 format). While this date is like a file timestamp, the date_product_modified and date_values_modified should be used to assess the age of the contents of the file or product.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lat_units_Attribute geospatial_lat_units] </td>
 
                <td valign="top">Units for the latitude axis. These are presumed to be "degree_north"; other options from udunits may be specified instead.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lat_resolution_Attribute geospatial_lat_resolution]</td>
 
 
 
                <td valign="top">Information about the targeted spacing of points in latitude. (Format is not prescribed.)</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lon_units_Attribute geospatial_lon_units] </td>
 
                <td valign="top">Units for the longitude axis. These are presumed to be "degree_east"; other options from udunits may be specified instead.</td>
 
                <!--<td valign="top">/gmi:MI_Metadata/gmd:spatialRepresentationInfo/gmd:MD_Georectified/gmd:axisDimensionProperties/gmd:MD_Dimension/gmd:resolution/gco:Measure/@uom</td> <td></td> <td>Extent</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_lon_resolution_Attribute geospatial_lon_resolution]</td>
 
                <td valign="top">Information about the targeted spacing of points in longitude. (Format is not prescribed.)</td>
 
                <!--<td valign="top">/gmi:MI_Metadata/gmd:spatialRepresentationInfo/gmd:MD_Georectified/gmd:axisDimensionProperties/gmd:MD_Dimension/gmd:resolution/gco:Measure</td> <td></td> <td>Extent</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_vertical_units_Attribute geospatial_vertical_units] </td>
 
                <td valign="top">Units for the vertical axis. These are presumed to be "meter" (of depth); other options from udunits may be specified. Note that the common oceanographic practice of using pressure for a vertical coordinate, while not strictly a depth, can be specified using the unit bar.</td>
 
                <!--<td valign="top" rowspan="3">/gmi:MI_Metadata/gmd:identificationInfo/gmd:MD_DataIdentification/gmd:extent/gmd:EX_Extent/gmd:verticalElement/gmd:EX_VerticalExtent/gmd:verticalCRS</td> <td></td> <td>Extent</td>-->
 
            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#geospatial_vertical_resolution_Attribute geospatial_vertical_resolution] </td>
 
                <td valign="top">Information about the targeted vertical spacing of points.</td>           
 
            </tr>
 
           
 
            <tr>
 
                <td valign="top">creator_uri</td>
 
                <td valign="top">The unique identifier of the person principally responsible for originating this data.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">creator_institution</td>
 
                <td valign="top">The institution that originated this data; should uniquely identify the institution.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">creator_institution_info</td>
 
                <td valign="top">Additional free text information for the institution that originated this data.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">creator_project</td>
 
                <td valign="top">The scientific project that originated this data; should uniquely identify the project.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">creator_project_info</td>
 
                <td valign="top">Additional free text information for the institution that originated this data.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher_uri</td>
 
                <td valign="top">The unique identifier of the person responsible for providing the data file or product.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher_institution</td>
 
                <td valign="top">The institution that provided the data file or equivalent product; should uniquely identify the institution.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher_institution_info</td>
 
                <td valign="top">Additional information for the institution that provided the data file or equivalent product; can include any information as free text, or in a structured format compatible with conversion to ncML (e.g., insensitive to whitespace).</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher_project</td>
 
                <td valign="top">The scientific project that provided the data file or equivalent product; should uniquely identify the project.</td>
 
            </tr>
 
            <tr>
 
                <td valign="top">publisher_project_info</td>
 
                <td valign="top">Additional information for the institution that provided the data file or equivalent product; can include any information as free text, or in a structured format compatible with conversion to ncML (e.g., insensitive to whitespace).</td>
 
            </tr>           
 
 
 
            <tr>
 
                <td valign="top">keywords_vocabulary</td>
 
                <td valign="top">If you are using a controlled vocabulary for the words/phrases in your "keywords" attribute, this is the unique name or identifier of the vocabulary from which keywords are taken. If more than one keyword vocabulary is used, each may be presented with a prefix (e.g., "CF:NetCDF COARDS Climate and Forecast Standard Names") and a following comma, so that keywords may optionally be prefixed with the controlled vocabulary key.</td>
 
            </tr>           
 
            <tr>
 
                <td valign="top">metadata_link</td>
 
                <td valign="top">A URI that gives the location of more complete metadata; a URL is recommended.</td>
 
            </tr>   
 
        </table>
 
 
 
==Highly Recommended Variable Attributes==
 
        <table width="95%" border="1" cellpadding="2" cellspacing="2">
 
            <tr>
 
                <th valign="top" width="200px">Attribute</th>
 
                <th valign="top">Description</th>
 
<!--                <th valign="top">THREDDS</th>
 
                <th valign="top">ISO 19115-2</th>
 
-->            </tr>   
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#long_name_Attribute long_name]</td>
 
                <td valign="top">A long descriptive name for the variable (not necessarily from a controlled vocabulary).</td>
 
<!--                <td valign="top">metadata/variables/variable@vocabulary_name</td>
 
                <td rowspan="2" valign="top">At present the ISO 19115-2 Standard supports only one name for a variable. Standard names can be provided as keywords with the appropriate thesaurus.</td>
 
-->            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#standard_name_Attribute standard_name]<br></td>
 
<!--                <td valign="top">A long descriptive name for the variable taken from a controlled vocabulary of variable names.</td>
 
                <td valign="top">metadata/variables/variable@vocabulary_name</td>
 
-->            </tr>
 
            <tr>
 
                <td valign="top">[http://www.unidata.ucar.edu/software/netcdf-java/formats/DataDiscoveryAttConvention.html#units_Attribute units]</td>
 
                <td valign="top">The units of the variables data values. This attributes value should be a valid udunits string.</td>
 
<!--                <td valign="top">metadata/variables/variable@units</td>
 
                <td valign="top">/gmi:MI_Metadata/gmd:contentInfo/gmi:MI_CoverageDescription/gmd:dimension/gmd:MD_Band/gmd:units</td>
 
-->            </tr>
 
            <tr>
 
                <td valign="top">coverage_content_type</td>
 
                <td valign="top">An ISO 19115-1 code to indicate the source of the data.</td>
 
<!--                <td valign="top"></td>
 
                <td valign="top">The valid values in the MD_CoverageContentTypeCode list are image, thematicClassification, physicalMeasurement, auxiliaryInformation, qualityInformation, referenceInformation, modelResult, coordinate</td>
 
-->            </tr>
 
        </table>
 
       
 
       
 
   
 
 
 
== Deprecated ==
 
The following terms and definitions are still recognized, but are no longer recommended for use by ACDD.
 
 
 
: Metadata_Convention: removed in favor of 'Conventions'
 
: date_created: deleted (use cases are addressed by 'date_product_available')
 
: date_issued: deleted in favor of 'date_product_available'
 
: date_modified: deleted in favor of 'date_product_modified' and 'date_values_modified'
 
: institution: though recommended by CF, removed in favor more detailed attributes - 'creator_institution', 'creator_institution_info', 'publisher_institution', 'publisher_institution_info' to provide more provenance information
 
----
 
 
 
=== Conformance Test ===
 
Conformance tests are available for verson 1.1. We hope to make a conformance test for this version available.
 
 
 
= Additional Materials =
 
== Mappings ACDD to other metadata dialects ==
 
[[Attribute Convention for Data Discovery (ACDD) Mappings]]
 
 
 
== Recommended Order of Precedence ==
 
[[Attribute Convention for Data Discovery (ACDD) Precedence]]
 
 
 
== Future Directions: Object Conventions for Data Discovery ==
 
[[Attribute Convention for Data Discovery (ACDD) Object Conventions]]
 
 
 
== ISO Translation Notes ==
 
http://wiki.esipfed.org/index.php?title=Attribute_Convention_for_Data_Discovery_(ACDD)_ISO_TranslationNotes
 
 
 
[[Category:Attribute Conventions Dataset Discovery]]
 
[[Category: Documentation Cluster]]
 
 
 
=Translation Revisions=
 
 
 
=Determining an Order of Precedence=
 
 
 
[[Category:Attribute Conventions Dataset Discovery]]
 
[[Category: Documentation Cluster]]
 

Latest revision as of 13:16, September 18, 2014

RESERVED FOR FUTURE VERSION. The most recent version (still in draft) is ACDD 1.3