GeoJSON Cheat Sheet

What is GeoJSON?

GeoJSON is an open geospatial data interchange format based on JavaScript Object Notation (JSON).

GeoJSON uses World Geodetic System 1984 (WGS84), with latitudes and longitudes in positive/negitve decimal degrees. WGS84 is the standard for GPS.

GeoJSON defines JSON objects and a syntax to represent data about geographic features, their properties, and their spatial extents.

The GeoJSON objects include:

• points (addresses and locations),
• line strings (streets, highways and boundaries),
• polygons (countries, provinces, tracts of land), and
• multi-part collections of these types.

What is JSON?

JavaScript Object Notation (JSON) is a lightweight, text-based, language-independent data interchange format.

It was derived from the ECMAScript Programming Language Standard.

JSON defines a small set of formatting rules for the portable representation of structured data.

GeoJSON Types

• Point
• LineString
• Polygon
• MultiPoint
• MultiLineString
• MultiPolygon
• Geometrycollection
• Feature
• FeatureCollection

ESRI Shapefile (*.shp) Types

#define SHPT_NULL           0
#define SHPT_POINT          1
#define SHPT_POLYLINE       3
#define SHPT_POLYGON        5
#define SHPT_MULTIPOINT     8
#define SHPT_POINTZ        11
#define SHPT_POLYLINEZ     13
#define SHPT_POLYGONZ      15
#define SHPT_MULTIPOINTZ   18
#define SHPT_POINTM        21
#define SHPT_POLYLINEM     23
#define SHPT_POLYGONM      25
#define SHPT_MULTIPOINTM   28
#define SHPT_MULTIPATCH    31

Escaping Special Characters in JSON / GeoJSON

Example of a Dominion Land Survey (DLS) Section in GeoJSON

{
   "success" : true,
   "type": "FeatureCollection",
   "features":
    [
       {
         "type": "Feature",
         "properties":
         {
            "TITLE":       "10-51-23-W4",
            "LATITUDE" :     53.38844354,
            "LONGITUDE":   -113.30751230,
            "NORTH":         53.39568232,
            "SOUTH":         53.38120475,
            "EAST" :       -113.29534775,
            "WEST" :       -113.31967684,
            "ZOOM": 14,
            "FILE_NAME": "423051",
            "TRM": "051234",
            "RGE": 23,
            "TWP": 51,
            "SEC": 10,
            "RA": "",
            "DESCRIPTOR": "SEC-10 TWP-051 RGE-23 MER-4",
            "PID": "423051100"

         },
         "geometry":
         {
            "type": "MultiPolygon",
            "coordinates":
            [
               [
                  [
                    [-113.29534887,53.38481764],
                    [-113.29534775,53.38120475],
                    [-113.30142060,53.38121331],
                    [-113.30749346,53.38122157],
                    [-113.31356631,53.38122954],
                    [-113.31963915,53.38123720],
                    [-113.31964855,53.38483459],
                    [-113.31965792,53.38843196],
                    [-113.31966739,53.39205714],
                    [-113.31967684,53.39568232],
                    [-113.31359568,53.39567596],
                    [-113.30751452,53.39566928],
                    [-113.30143338,53.39566229],
                    [-113.29535225,53.39565498],
                    [-113.29535112,53.39204276],
                    [-113.29534998,53.38843053],
                    [-113.29534887,53.38481764]
                  ]
               ]
            ]
         }
       }
    ]
}

References

• Bing Maps: Using GeoJSON
  Creating and Hosting a map
  Microsoft
  
• Bing Maps: Read GeoJSON object and plot
  Reads from a GeoJSON string and renders it as a polygon on a Bing maps
  Microsoft
  
• Bing Maps: Getting a Bing Maps Key
  As of April 2023, there are rather generous usage limits on the Basic (Free) Account
  Microsoft
  
• Using GeoJSON with Leaflet
  Leaflet is an open-source JavaScript library for mobile and desktop interactive maps
  by Volodymyr Agafonkin
  
• OpenLayers GeoJSON Example
  OpenLayers is an open-source JavaScript Library released under the 2-clause BSD License
  NOTE: We have used Bing and Leaflet, but we have not tried Openlayers.
  
• RFC7946
  The GeoJSON Format
  
• RFC8259
  The JavaScript Object Notation (JSON) Data Interchange Format
  
• GeoJSON Viewer & Validator
  Online 3rd Party Lint Checker for GeoJson
  https://geojsonlint.com
  
• How to Escape Special Characters in a JSON String
  Stack Overflow
  
• US Library of Congress
  Recommended Formats Statement
  Geographic Information System (GIS) - Vector Data
• Salesforce: Apex Developer Guide Pages
  • Sending Username and Password
  • JSON Parsing
  Salesforce is a popular Customer Relations Management (CRM) platform.