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GeoJSON, Version 1.0

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Format Description Properties Explanation of format description terms

Identification and description Explanation of format description terms

Full name GeoJSON, Version 1.0
Description

GeoJSON is a geospatial data interchange format based on JavaScript Object Notation (JSON). GeoJSON is a format for representing a variety of geographic data structures. A GeoJSON object may represent a geometry, a feature, or a collection of features. GeoJSON supports the geometry types listed below as object types. A GeoJSON feature contains a geometry object and additional properties; a feature collection represents a list of features.

A complete GeoJSON data structure is always a single JSON object consisting of a collection of name/value pairs, known as members. The GeoJSON specification imposes additional constraints to define a GeoJSON object:

  • The GeoJSON object must have a member with the name "type". The value of the type member must be one of: Point, MultiPoint, LineString, MultiLineString, Polygon, MultiPolygon, GeometryCollection, Feature, or FeatureCollection.
  • A GeoJSON object may have an optional "crs" member, the value of which must be a coordinate reference system object
  • A GeoJSON object may have a "bbox" member, the value of which must be a bounding box array
Production phase An interchange format for geospatial data, typically used during data collection or to transmit selected structured data to a system that will further manipulate the data and/or present it to end users.
Relationship to other formats
    Subtype of JSON, JSON (JavaScript Object Notation)
    Has extension TopoJSON, describes lines and polygons in terms of shared arcs. Not described separately on this resource at this time.

Local use Explanation of format description terms

LC experience or existing holdings  
LC preference  

Sustainability factors Explanation of format description terms

Disclosure Openly documented. Developed by a group of individuals in 2008. Published as an Internet Draft in January 2014.
    Documentation The GeoJSON Format at geojson.org
Adoption

Rapidly adopted for Web applications involving mapping. The GeoJSON site has a page listing GeoJSON users.

GeoJSON is used for defining geographic coverage of an App that uses Apple's iOS MapKit. See instructions on Providing Directions in iOS. The geographic coverage file is used by the Maps app and the App Store, to look up apps on the App Store that are capable of providing directions in a target region.

Although ESRI supports a more complex JSON-based format in its GeoServices REST Specification, various open source projects, including projects by ESRI are developing conversion tools. See Useful References below.

    Licensing and patents No licensing concerns.
Transparency

GeoJSON is based on text using UNICODE and uses a very simple structure. The names used for object types defined in the specification are common English words. GeoSON is easy for humans to read and write and for machines to parse and generate. UTF-8 is most commonly used, but UTF-16 and UTF-32 are also permitted.

Self-documentation See JSON.
External dependencies None
Technical protection considerations None

Quality and functionality factors Explanation of format description terms

Dataset
Normal functionality

GeoJSON is based on JSON and inherits the same limitations.

JSON is intended for data interchange and does not employ strong data-typing for numbers or have explicit support for dates. All data is represented as text, with numbers being in base 10 as sequences of digits (including the common exponent notation to express very small or very large numbers). JSON is not appropriate for applications requiring binary data. Boolean values true and false are allowed as values. There is minimal support for coding missing data, using the null value.

Support for software interfaces (APIs, etc.) GeoJSON is sufficiently simple that support for reading or writing it has been integrated into almost every GIS system or tool used for applications on the Web.
Data documentation (quality, provenance, etc.) TBD
Beyond normal functionality None.
GIS images and datasets
Normal functionality

The purpose of GeoJSON is to support map generation by providing georeferencing information for features through geospatial positions, and geometry objects constructed from positions. Positions are represented in longitude, latitude, and, optionally altitude, as decimal numbers. The default (and strongly recommended) Coordinate Reference System is WGS84, but alternative systems can be specified. The recommended nomenclature for CRS systems is to use OGC (Open Geospatial Consortium) URNs, for example urn:ogc:def:crs:OGC::CRS84 (for WGS84). EPSG identifiers, originally from the European Petroleum Survey Group and now maintained by the International Association of Oil and Gas Producers (OGP) can also be used. Alternatively, the parameters for a CRS can be linked to by URL.

Support for GIS metadata There are no special provisions within GeoJSON for representing richer GIS metadata as defined by FGDC or ISO 19115.

File type signifiers and format identifiers Explanation of format description terms

Tag Value Note
Filename extension json
Wikipedia entry for GeoJSON indicates that the file extension used for JSON is used for GeoJSON.
Internet Media Type application/json
Wikipedia entry for GeoJSON indicates that the MIME type registered with IANA for JSON is used for GeoJSON.
Magic numbers See related format.  See JSON.

Notes Explanation of format description terms

General  
History  

Format specifications Explanation of format description terms


Useful references

URLs


Last Updated: Monday, 27-Feb-2017 09:55:24 EST