The Federal Geographic Data Committee's (FGDC) Content Standard for Digital Spatial Metadata (CSDGM) is a well-known metadata standard that has been used in North America and around the world for many years. This is the type of metadata created by default with ArcGIS Desktop 9.3.1.
You can create complete FGDC metadata content in the current version of ArcGIS Desktop in the Description tab when you use the FGDC CSDGM Metadata style. This guide clearly illustrates where to put the information associated with each FGDC metadata element. Some metadata elements are organized and named differently in the ArcGIS metadata editor than in the FGDC metadata standard. However, when you export metadata from ArcGIS to the FGDC XML format, all ArcGIS metadata content associated with the CSDGM standard is extracted and arranged correctly to create a complete FGDC-formatted metadata XML file that can be validated using either the metadata parser utility, known as mp, or the FGDC XML schemas.
The FGDC CSDGM standard is divided into seven main sections. This topic is split into sections that correspond with the standard. Production rules for each metadata section are provided in tables. Screen captures following each table show where to put an element's content in the ArcGIS metadata editor. Additional tables contain the production rules for each compound metadata element. If information is required to explain what to type or how ArcGIS handles an element's content, it will be provided in a paragraph that immediately precedes the associated screen capture.
FGDC metadata includes three reusable sections of information: Citation Information, Time Period Information, and Contact Information. Separate sections in this topic illustrate how to provide their content. In the seven main metadata sections, if an element references a reusable section, the screen capture will only show how to add that section, for example, a contact. Refer to the reusable section's detailed instructions for more information. The exception is the citation that describes the item itself, where some content is handled differently than for other resources that may be cited in the metadata.
Section zero in the CSDGM provides production rules for the seven metadata sections themselves, indicating which sections are mandatory. This section is presented first in the topic below. It provides links that can quickly take you to the detailed information for each metadata section further down in this topic.
Some information, such as an item's detailed spatial reference properties, can only be added to an item's metadata by the metadata synchronization process. To include this information in an item's metadata, automatic updates must be turned on in the Options dialog box. The only way to change the properties of an item that are recorded in its metadata is to change the item's data or settings in ArcGIS. The next time the item's metadata is synchronized after the item has been updated, its current properties will be updated accordingly in its metadata. The screen captures may illustrate where to find the item's properties in the metadata display, so you can check that this information has been recorded by the synchronization process.
The following information applies to all FGDC metadata content that is edited, upgraded, and imported in ArcGIS.
In ArcGIS metadata, all dates must be valid dates that consist of a year, a month, and a day. To enter this information in the Description tab , click the calendar control and click the appropriate date. Times in ArcGIS metadata must be valid, and must include hours, minutes, and seconds. To enter this information, click the portion of the time you want to change and type in the appropriate value. The up and down arrows can only be used to change the hour. For more details about using the calendar and time controls, see the Time Period Information section.
If an item's existing FGDC metadata contains a date that is only a year, when this metadata is upgraded or imported into ArcGIS the date is converted to the first of January in that year. If the original date consists of a year and a month, this date is converted to the first day of that month in the specified year when the metadata is imported or upgraded. If the original value provided is a string, such as Spring 2003 , this information can't be converted to a date; the value won't be imported or upgraded. Similarly, if the original date is invalid, for example, because the date didn't adhere to the FGDC yyyymmdd format, the date won't be imported or upgraded.
When describing an item's time period, provide a date range that runs from the first day to the last day of the appropriate year or month instead of providing a partial date. Instead of specifying spring in a given year, specify a range of months during which the data was collected or the map was created.
If the original metadata includes only a partial time, zero seconds, minutes, or hours will be added as appropriate. If the original time provided is a string, such as 2 a.m. , this information can't be converted to a time; the value won't be imported or upgraded. Times can't be provided in ArcGIS metadata without an accompanying date.
In FGDC metadata, some elements that typically require dates or times may allow text, such as unknown , unpublished material , or now . This information will be upgraded or imported to ArcGIS metadata. However, at present, imprecise dates and times such as these can't be edited in the Description tab . If more detailed dates and times are specified in the item's ArcGIS metadata, they will be used in place of the imprecise values when ArcGIS metadata is exported. Otherwise, the original imprecise dates and times will be exported to the FGDC format.
In FGDC metadata, it is common practice to include the text None in mandatory elements where the information associated with that element is either unknown or inapplicable. For example, whenever keywords are provided, a thesaurus must be specified even if one wasn't used. The same practice is used if there are no access and use constraints associated with the item, because these metadata elements are mandatory.
When an item's existing FGDC metadata is upgraded or imported to ArcGIS, the value None isn't included in the item's ArcGIS metadata. Do not add any thesaurus citation information in ArcGIS metadata if a set of keywords wasn't selected from a thesaurus. Do not add any constraint information if there are no constraints to report. When metadata is exported to an FGDC-formatted XML file, the exporter will automatically add in these elements with the value None .
In FGDC metadata, many elements have a domain where the value can be one of a specified set of values or any other text. As a result, people often write different phrases that express the same meaning in the same metadata element. The equivalent metadata elements in the ISO metadata standards are typically associated with codelists. A codelist is a set of codes that communicate a specific concept unambiguously; free text is not supported. The ISO metadata standards include codes that articulate many of the same concepts that are defined in the FGDC CSDGM standard. In some cases, the North American Profile added codes to these codelists to include FGDC CSDGM concepts that were missing in the base standard.
The associated ArcGIS metadata elements use codelists. When an item's existing FGDC metadata is upgraded or imported to ArcGIS, the word or phrase provided in the FGDC metadata element is converted to a coded value. The phrases defined in the FGDC CSDGM standard and some well-known variations of them will be successfully matched to the appropriate code. North American Profile codes are used in cases where the base ISO metadata standard codes are insufficient.
If one of the phrases suggested in the FGDC CSDGM standard is misspelled, or if an alternate phrase was used, the upgrade process is unlikely to recognize it even though it has the same meaning. In this case, ArcGIS will be unable to assign the appropriate code that corresponds to the original value. Be sure to check an item's upgraded or imported metadata. If any values were not successfully matched, pick the appropriate code from the codelist and save your changes.
An element is said to be repeating if many of those elements occur in the item's metadata. For example, many keywords are allowed. Each keyword is stored in a separate keyword element—the element repeats once for each keyword that has been provided. From an XML perspective, repeating elements are not required to be maintained in a specific order.
XML elements can be processed in different ways. Some of them maintain document order; that is, elements are always handled sequentially. If XML elements are always handled in document order it can appear as if the order of repeating elements is being maintained even if this is not technically true. Other processing methods handle XML elements in random order.
When an item's existing FGDC metadata is upgraded or imported, metadata elements are processed randomly. As a result, you may find that after upgrading or importing FGDC metadata to ArcGIS, repeating elements such as keywords may not occur in the same order as in the original FGDC-formatted metadata document. This is a one-time change that may occur during the import or upgrade process. While this change might be visually disconcerting, the metadata is not invalid just because the XML elements were rearranged.