Interoperability and standards support > GML support in ArcGIS
An overview of GML support in ArcGIS |
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Release 9.2
Last modified January 26, 2007 |
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The Open Geospatial Consortium's (OGC) Geography Markup Language Encoding Specification (GML) is a standard protocol for encoding geometry and attributes using XML. An important concept to understand is that GML is not a single format. Instead, it is a mechanism for defining almost any geospatial format. This capability supports the need for an organization to publish its own information model regardless of whether it is simple, rich, or somewhere in between.
GML was designed to be very broad and cover many needs. For example, the GML 3 specification describes close to 1,000 tags (named objects) and incorporates a number of potential geometry types for describing features. These include simple or aggregate features, circular and elliptical arcs, 3D, topology, time, metadata, and time-based information and features.
Each GML encoding will adhere to its own profile which you can think of simply as a specific format. And like any other data format, each GML profile will require its own translator for ingestion and use in your system.
GML dataset formats can be simple, or they may be complex. One profile is the GML Simple Features Profile. This specification implements the OGC Simple Features standard using GML.
ArcGIS supports this GML simple features profile out-of-the-box for all users. ArcGIS also provides an optional suite of data conversion tools as part of the Data Interoperability Extension so that users can add custom GML formats that support any particular GML profile. Using the Data Interoperability Extension, users can work with a series of GML profiles.
ESRI recommends use of the OGC Simple Features profile for open information exchange. In order for users to openly share information across systems using an open profile, the chosen profile must be adopted by many organizations. GML simple features was designed as a common format for interoperability by many GIS software organizations who are committed to providing support. We recommend the use of GML Simple Features where possible. ArcGIS includes direct converters to read, write, and serve GML Simple Features.
ESRI supports creation and use of complex GML formats using the Data Interoperability Extension. This ArcGIS extension supports the ability to create and use custom formats for features. The Data Interoperability Extension to ArcGIS includes the FME workbench, which can be used to define and use custom formats that can support more sophisticated GML profiles. For example, you can use this extension to add support to ArcGIS for your own GML profile.