The spatialReference object is located at the top level of the web map JSON hierarchy. In addition to this, it is also available within the operationalLayer and basemap objects.
Many predefined spatial references have already been defined and are available for use. A spatial reference can be defined using a well-known ID (WKID) or well-known text (WKT). The default tolerance and resolution values for the associated coordinate system are used. It is required to have this property saved within the web map.
Referenced by: anchorPoint, centerPoint, extent, Georeference, layerDefinition, mapLocation, multipointGeometry, pointGeometry, polygonGeometry, polylineGeometry, Query Table DataSource, tileInfo, Web Link Chart, Webmap
Properties
| Property | Details |
|---|---|
| falseM | (Optional) The false origin of coordinate M values. The default is determined by the spatial reference. |
| falseX | (Optional) The false origin of coordinate X values. The default is determined by the spatial reference. |
| falseY | (Optional) The false origin of coordinate Y values. The default is determined by the spatial reference. |
| falseZ | (Optional) The false origin of coordinate Z values. The default is determined by the spatial reference. |
| latestWkid | (Optional) Identifies the current wkid value associated with the same spatial reference. For example a WKID of '102100' (Web Mercator) has a latestWKid of '3857'. |
| mTolerance | (Optional) The tolerance value reflects the accuracy of coordinates. If one coordinate is within the tolerance value of another, they are interpreted as being at the same location. This value is used in relational and topological operations when determining whether two points are close enough to be given the same coordinate value or they are far enough apart to each have their own coordinate value. The default tolerance is set to 0.001 meters or its equivalent in map units. |
| mUnits | (Optional) The number of distinct values that can be represented per one unit of floating point coordinates. The resolution for M is 1/mUnits. The default resolution is set to 0.0001 meters or its equivalent in map units. |
| wkid | The well-known ID (WKID) of the coordinate system. |
| wkt | The well-known text (WKT) of the coordinate system. |
| wkt2 | The well-known text of the coordinate system as defined by OGC standard for well-known text strings. |
| xyTolerance | (Optional) The tolerance value reflects the accuracy of coordinates. If one coordinate is within the tolerance value of another, they are interpreted as being at the same location. This value is used in relational and topological operations when determining whether two points are close enough to be given the same coordinate value or they are far enough apart to each have their own coordinate value. The default tolerance is set to 0.001 meters or its equivalent in map units. |
| xyUnits | (Optional) The number of distinct values that can be represented per one unit of floating point coordinates. The resolution for X and Y is 1/xyUnits. The default resolution is set to 0.0001 meters or its equivalent in map units. |
| zTolerance | (Optional) The tolerance value reflects the accuracy of coordinates. If one coordinate is within the tolerance value of another, they are interpreted as being at the same location. This value is used in relational and topological operations when determining whether two points are close enough to be given the same coordinate value or they are far enough apart to each have their own coordinate value. The default tolerance is set to 0.001 meters or its equivalent in map units. |
| zUnits | (Optional) The number of distinct values that can be represented per one unit of floating point coordinates. The resolution for Z is 1/zUnits. The default resolution is set to 0.0001 meters or its equivalent in map units. |
Can be one of the following:
Additional information
All operational layers in the map are drawn or requested in the spatial reference of the basemap layers.
The basemap defines the map spatial reference and tiling scheme. Each baseMapLayer must be in the same spatial reference and tiling scheme.
For a complete list of supported IDs and their corresponding definition strings, see:
Projected Coordinate Systems Listing
Geographic Coordinate Systems Listing
Vertical Coordinate Systems Listing
Additional information regarding how web maps work with geometry and spatial reference can be found on the Resource Center:
ArcGIS Server REST API Geometry object
wkid Example
{
"wkid": 102100,
"latestWkid": 3857
}wkt & wkt2 - can be represented as wkt (transitioning to wkt2 and hence both) Example
{
"wkt": "PROJCS[\"WGS_1984_Web_Mercator_Auxiliary_Sphere\",GEOGCS[\"GCS_WGS_1984\",DATUM[\"D_WGS_1984\",SPHEROID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Mercator_Auxiliary_Sphere\"],PARAMETER[\"False_Easting\",0.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",0.0],PARAMETER[\"Standard_Parallel_1\",0.0],PARAMETER[\"Auxiliary_Sphere_Type\",0.0],UNIT[\"Meter\",1.0]]",
"wkt2": "PROJCRS[\"WGS_1984_Web_Mercator_Auxiliary_Sphere\",BASEGEOGCRS[\"GCS_WGS_1984\",DYNAMIC[FRAMEEPOCH[1990.5],MODEL[\"AM0-2\"]],DATUM[\"D_WGS_1984\", ELLIPSOID[\"WGS_1984\",6378137.0,298.257223563,LENGTHUNIT[\"Meter\",1.0]]],PRIMEM[\"Greenwich\",0.0,ANGLEUNIT[\"Degree\",0.0174532925199433]],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],CONVERSION[\"Mercator_Auxiliary_Sphere\",METHOD[\"Mercator_Auxiliary_Sphere\"],PARAMETER[\"False_Easting\",0.0,LENGTHUNIT[\"Meter\",1.0]],PARAMETER[\"False_Northing\",0.0,LENGTHUNIT[\"Meter\",1.0]],PARAMETER[\"Central_Meridian\",0.0,ANGLEUNIT[\"Degree\",0.0174532925199433]],PARAMETER[\"Standard_Parallel_1\",0.0,ANGLEUNIT[\"Degree\",0.0174532925199433]],PARAMETER[\"Auxiliary_Sphere_Type\",0.0]],CS[Cartesian,2],AXIS[\"Easting (X)\",east,ORDER[1]],AXIS[\"Northing (Y)\",north,ORDER[2]],LENGTHUNIT[\"Meter\",1.0]]"
}wkt - all versions 2.28 and earlier. Example
{
"wkt": "PROJCS[\"WGS_1984_Web_Mercator_Auxiliary_Sphere\",GEOGCS[\"GCS_WGS_1984\",DATUM[\"D_WGS_1984\",SPHEROID[\"WGS_1984\",6378137.0,298.257223563]],PRIMEM[\"Greenwich\",0.0],UNIT[\"Degree\",0.0174532925199433]],PROJECTION[\"Mercator_Auxiliary_Sphere\"],PARAMETER[\"False_Easting\",0.0],PARAMETER[\"False_Northing\",0.0],PARAMETER[\"Central_Meridian\",0.0],PARAMETER[\"Standard_Parallel_1\",0.0],PARAMETER[\"Auxiliary_Sphere_Type\",0.0],UNIT[\"Meter\",1.0]]"
}wkt2 - can be represented only as wkt2, so will not contain wkt Example
{
"wkt2": "PROJCRS[\"WGS_1984_Web_Mercator_Auxiliary_Sphere\",BASEGEOGCRS[\"GCS_WGS_1984\",DYNAMIC[FRAMEEPOCH[1990.5],MODEL[\"AM0-2\"]],DATUM[\"D_WGS_1984\", ELLIPSOID[\"WGS_1984\",6378137.0,298.257223563,LENGTHUNIT[\"Meter\",1.0]]],PRIMEM[\"Greenwich\",0.0,ANGLEUNIT[\"Degree\",0.0174532925199433]],CS[ellipsoidal,2],AXIS[\"Latitude (lat)\",north,ORDER[1]],AXIS[\"Longitude (lon)\",east,ORDER[2]],ANGLEUNIT[\"Degree\",0.0174532925199433]],CONVERSION[\"Mercator_Auxiliary_Sphere\",METHOD[\"Mercator_Auxiliary_Sphere\"],PARAMETER[\"False_Easting\",0.0,LENGTHUNIT[\"Meter\",1.0]],PARAMETER[\"False_Northing\",0.0,LENGTHUNIT[\"Meter\",1.0]],PARAMETER[\"Central_Meridian\",0.0,ANGLEUNIT[\"Degree\",0.0174532925199433]],PARAMETER[\"Standard_Parallel_1\",0.0,ANGLEUNIT[\"Degree\",0.0174532925199433]],PARAMETER[\"Auxiliary_Sphere_Type\",0.0]],CS[Cartesian,2],AXIS[\"Easting (X)\",east,ORDER[1]],AXIS[\"Northing (Y)\",north,ORDER[2]],LENGTHUNIT[\"Meter\",1.0]]"
}