Geographic Data Files
Encyclopedia
Geographic Data Files or GDF is an interchange file format
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...

 for geographic data.
In contrast with generic GIS
Geographic Information System
A geographic information system, geographical information science, or geospatial information studies is a system designed to capture, store, manipulate, analyze, manage, and present all types of geographically referenced data...

 formats, GDF provides detailed rules for data capture and representation, and an extensive catalog of standard features, attributes and relationships. Most recent extension expand applicability further towards Pedestrian Navigation, 3-D map rendering, and Advanced Driver Assistance Systems
Advanced Driver Assistance Systems
Advanced Driver Assistance Systems, or ADAS, are systems to help the driver in its driving process. When designed with a safe Human-Machine Interface it should increase car safety and more generally road safety.Examples of such a system are:...

 (ADAS).

GDF is commonly used for data interchange in many industries such as Automotive navigation system
Automotive navigation system
An automotive navigation system is a satellite navigation system designed for use in automobiles. It typically uses a GPS navigation device to acquire position data to locate the user on a road in the unit's map database. Using the road database, the unit can give directions to other locations...

, fleet management
Fleet management
Fleet management is the management of a company's vehicle fleet.Fleet management includes commercial motor vehicles such as cars, vans and trucks. Fleet management can include a range of functions, such as vehicle financing, vehicle maintenance, vehicle telematics , driver management, speed...

, dispatch management, road traffic analysis, traffic management, Automatic Vehicle Location
Automatic vehicle location
Automatic vehicle location is a means for automatically determining the geographic location of a vehicle and transmitting the information to a requester....

.

Orignated as a flat plain-text file, GDF is not intended to be used directly for any large scale geographic application and normally requires conversion into a more efficient format. Consumability has been increased with most-recent developments for XML and SQL renditions.

The maps in GDF format are provided by many map vendors such as Navteq
NAVTEQ
Navteq is a Chicago, Illinois-based provider of Geographic Information Systems data and is a dominant company in providing the base electronic navigable maps...

, TomTom
TomTom
TomTom NV is a Dutch manufacturer of automotive navigation systems, including both stand-alone units and software for personal digital assistants and mobile telephones. It is the leading manufacturer of navigation systems in Europe. TomTom's customer service is located in Amsterdam, Netherlands...

, Mapscape BV
Mapscape BV
Mapscape BV is a Netherlands-based independent Business-to-business digital maps service provider. The company is active in the navigation and automotive market. Mapscape is involved in content aggregation, compilation and testing of digital maps for navigation purposes. The maps are targeted for...

, GeoSmart
GeoSmart
GeoSmart Ltd is a provider of location based services and digital mapping data and images for the Oceania area, notably New Zealand. The company is one of only a handful of global companies producing digital maps for use in GPS applications....

, Automotive Navigation Data
Automotive Navigation Data
AND Automotive Navigation Data is one of the few companies in the world supplying digital map data for GPS-based applications. After the take over of Navteq by Nokia en Tele Altas by TomTom AND is the last independent supplier of digital maps...

, AutoNavi and NavInfo.

Standardisation

GDF is an international standard that is used to model, describe and transfer road networks and other geographic data.

The standard was initially drawn up by CEN
European Committee for Standardization
The European Committee for Standardization or Comité Européen de Normalisation , is a non-profit organisation whose mission is to foster the European economy in global trading, the welfare of European citizens and the environment by providing an efficient infrastructure to interested parties for...

 in co-operation with digital map providers, automotive and electronic equipment manufacturers. The outcome of these standardisation efforts (CEN GDF 3.0, or ENV14825:1996) has formed the major input to a global standard created by ISO/TC204 Sub Working group
Working group
A working group is an interdisciplinary collaboration of researchers working on new research activities that would be difficult to develop under traditional funding mechanisms . The lifespan of the WG can last anywhere between a few months and several years...

 3:
  • ISO GDF 4.0, formally referred to ISO14825:2004, now replaced by
  • ISO GDF 5.0, formally referred to ISO14825:2011.


However, despite the existence of a ISO GDF standard, the nature of model abstractions as well as semantic interpretations and proprietary content extensions lead to interoperability issues between flavors of GDF map products from different vendors. In practice the GDF files are not fully interchangeable due to vendor specific extensions. To this end, GDF5.0 provides major improvements in terms of extended meta data and flags for signalling implementation choices.

The new GDF5.0

The specifications of GDF5.0 were developed and compiled between 2001 and 2008, involving experts from Australia, Canada, Czech Republic, France, Germany, Japan, Republic of Korea, the Netherlands, and the United States of America. Extensive activities towards harmonization with ISO/TC211 standards were undertaken. GDF 5.0 was published in July 2011.

Major GDF5.0 enhancements include UML model migration & refinements; harmonization with linear referencing and geo-spatial web standards; support for 3-D content and time coordinates; comprehensive character set and phonetic representations; and new XML and SQL based delivery formats.

Background and Rationale of GDF Standardization

By the late 1980s, producers and users of digital road map data became increasingly aware of the need for a common data interchange standard. Lack of such a standard was seen as an impediment to the commercial growth and success of industries using such data. Before the advent of the Intelligent Transport Systems (ITS) industry, development of spatial data interchange standards was done mostly on a regional basis and not designed for the specialised requirements of road transport-related applications.

In the 1990s, the GDF standard was instrumental in enabling the European business-to-business (B2B) market for in-vehicle navigation in that it provided interoperability for exchanging digital map data between map manufacturers and navigation system integrators. The GDF specifications provided a base for both the capturing of geographic content and the exchanging of it. Its original design foresaw a powerful, application-independent model, while its initial rendition as a standard specifically addressed the requirements for the richness of navigable map databases. Since then, GDF has evolved in terms of boosted data modelling capabilities, broadened international applicability, expanded geographic domains, and diversified exchange formats. As a result, GDF covers a wide range of application domains and has been adapted to many geo-spatial technologies.

See also

  • OGC Standards
    Open Geospatial Consortium
    The Open Geospatial Consortium , an international voluntary consensus standards organization, originated in 1994. In the OGC, more than 400 commercial, governmental, nonprofit and research organizations worldwide collaborate in a consensus process encouraging development and implementation of open...

  • Automotive navigation system
    Automotive navigation system
    An automotive navigation system is a satellite navigation system designed for use in automobiles. It typically uses a GPS navigation device to acquire position data to locate the user on a road in the unit's map database. Using the road database, the unit can give directions to other locations...

  • Navigation
    Navigation
    Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...

  • Global Positioning System
    Global Positioning System
    The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

     (GPS)
  • Geography Markup Language
    Geography Markup Language
    The Geography Markup Language is the XML grammar defined by the Open Geospatial Consortium to express geographical features. GML serves as a modeling language for geographic systems as well as an open interchange format for geographic transactions on the Internet...

  • Keyhole Markup Language
    Keyhole Markup Language
    Keyhole Markup Language is an XML notation for expressing geographic annotation and visualization within Internet-based, two-dimensional maps and three-dimensional Earth browsers. KML was developed for use with Google Earth, which was originally named Keyhole Earth Viewer. It was created by...

  • Map database management
    Map database management
    Map database management stems from navigation units becoming more common in automotive vehicles . They serve to perform usual navigation functions, such as finding a route to a desired destination and guiding the driver to it or determining the vehicle’s location and providing information about...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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