SpatialReference

// set the spatial reference of a view to WebMercator using wkid
const view = new SceneView({
  container: "viewDiv",
  map: map,
  spatialReference: {
    wkid: 3857
  }
});

// set the spatial reference of a geometry
// to WGS84 using the WGS84 property
const point = new Point({
  x: 10.1,
  y: 47.4,
  spatialReference: SpatialReference.WGS84
});

Property Overview

Property Details

declaredClass Stringreadonly inherited

Since: ArcGIS Maps SDK for JavaScript 4.7

The name of the class. The declared class name is formatted as esri.folder.className.

imageCoordinateSystem Object

Since: ArcGIS Maps SDK for JavaScript 4.13

An image coordinate system defines the spatial reference used to display the image in its original coordinates without distortion, map transformations or ortho-rectification. Typically, ImageryLayer is displayed in the spatialReference of the view. In some cases, converting images into map coordinates can cause your images to look skewed or distorted because of the various transformations and terrain corrections that are used. Since there is no distortion with images in the image coordinate system, it is ideal for using with oblique imagery and mensuration.

The image can be displayed in its original coordinates only in 2D MapView with a top-uprotation which is always oriented in the look of direction of the dataset. This works similarly to an in-car navigation system where the choices are often either north is at the top of the screen (therefore, not using a top up option) or the screen rotates so the travel direction is always displayed at the top.

See also

• Sample - ImageryLayer image coordinate system

• Image coordinate system

• Image space analysis

• ImageryLayer.getCatalogItemICSInfo()

Example

// get image coordinate system of the specified catalog item
// for example Raster.OBJECTID = 1600
layer.getCatalogItemICSInfo(imageId).then(function(info) {
// create a spatialReference object and set its
// imageCoordinateSystem property
 let sr = { // autocasts to esri/geometry/SpatialReference
   imageCoordinateSystem: { id: imageId }
 };

 // Calculate an extent for the mapview based on the image's extent
 // in its original coordinate system
 const width = document.getElementById("viewDiv").getBoundingClientRect().width;
 const height = document.getElementById("viewDiv").getBoundingClientRect().height;
 const newExt = info.icsExtent.clone();
 const scaleFactor = 5;
 newExt.xmin = (newExt.xmin + newExt.xmax - width * scaleFactor) / 2;
 newExt.xmax = newExt.xmin + width * scaleFactor;
 newExt.ymin = (newExt.ymin + newExt.ymax - height * scaleFactor) / 2;
 newExt.ymax = newExt.ymin + height * scaleFactor;
 newExt.spatialReference = sr;

 // set the MapView's spatialReference to the image's coordinate system
 // and the extent to the extent calculated above
 view = new MapView({
   container: "viewDiv",
   map: map,
   spatialReference: sr,
   extent: newExt
 });
});

isGeographic Booleanreadonly

Indicates if the spatial reference refers to a geographic coordinate system.

isWebMercator Booleanreadonly

Indicates if the wkid of the spatial reference object is one of the following values: 102113, 102100, 3857.

isWGS84 Booleanreadonly

Indicates if the wkid of the spatial reference object is 4326.

isWrappable Booleanreadonly

Indicates if the spatial reference of the map supports wrapping around the International Date Line. Value is true if the spatial reference is Web Mercator or WGS84.

metersPerUnit Numberreadonly

Since: ArcGIS Maps SDK for JavaScript 4.26

The factor to convert one unit value in the spatial reference's unit to meters.

Examples

// Convert 1 pixel in a MapView to meters
const pixelInMeter = view.resolution * view.spatialReference.metersPerUnit;

// Measure the geodesic distance between two points in the view's unit
const distanceInViewUnit = geodesicUtils.geodesicDistance(pointA, pointB, "meters")  / view.spatialReference.metersPerUnit;

const DPI = 96
const inchesPerMeter = 39.37;

// Get the scale for an extent
function getScale(extent, viewWidth) {
  const unitValue = extent.spatialReference.metersPerUnit;
  return (extent.width / viewWidth) * unitValue * inchesPerMeter * DPI;
}

unit null|Stringreadonly

Since: ArcGIS Maps SDK for JavaScript 4.26

The unit of the spatial reference. Returns null if no unit could be determined.

Some values of the possible values listed here cannot be used as parameters for certain functions. For example, geodesicUtils.geodesicDistance() only accepts meters, feet, us-feet. For other values, you can use the meters unit and use metersPerUnit convert to the spatial reference's unit.

Possible Values:"degrees"|"meters"|"feet"|"us-feet"|"clarke-feet"|"clarke-yards"|"clarke-links"|"sears-yards"|"sears-feet"|"sears-chains"|"benoit-1895-b-chains"|"indian-yards"|"indian-1937-yards"|"gold-coast-feet"|"sears-1922-truncated-chains"|"50-kilometers"|"150-kilometers"

See also

• metersPerUnit

WebMercator SpatialReferencestatic

A convenience spatial reference instance for Web Mercator.

Example

// returns true if the webMercatorUtils can
// project geometries from WGS84 to Web Mercator
let canProjectWGS84toWebMercator = webMercatorUtils.canProject(SpatialReference.WGS84, SpatialReference.WebMercator);

WGS84 SpatialReferencestatic

A convenience spatial reference instance for WGS84.

Example

// returns true if the webMercatorUtils can
// project geometries from WGS84 to Web Mercator
let canProjectWGS84toWebMercator = webMercatorUtils.canProject(SpatialReference.WGS84, SpatialReference.WebMercator);

wkid Number

The well-known ID of a spatial reference. See Using spatial references for a list of supported spatial references.

wkt String

The well-known text that defines a spatial reference.

Method Overview

Method Details

addHandles(handleOrHandles, groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.

// Manually manage handles
const handle = reactiveUtils.when(
  () => !view.updating,
  () => {
    wkidSelect.disabled = false;
  },
  { once: true }
);

this.addHandles(handle);

// Destroy the object
this.destroy();

Parameters

handleOrHandles WatchHandle|WatchHandle[] Handles marked for removal once the object is destroyed.

groupKey * optional Key identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.

clone(){SpatialReference}

Returns a deep clone of the spatial reference object.

Returns

Type	Description
SpatialReference	Returns a deep clone of the spatial reference object.

equals(spatialReference){Boolean}

Checks if the specified spatial reference object has the same wkid or wkt as this spatial reference object.

Parameter

spatialReference SpatialReference The spatial reference to compare to.

Returns

Type	Description
Boolean	Returns true if the input spatial reference object has the same wkid or wkt as this spatial reference object.

Example

require(["esri/geometry/SpatialReference"], function(SpatialReference) {
  const sr1 = new SpatialReference({ wkid: 4326 });
  const sr2 = new SpatialReference({ wkid: 4326 });
  console.log(sr1.equals(sr2)); // true
});

fromJSON(json){*}static

Creates a new instance of this class and initializes it with values from a JSON object generated from an ArcGIS product. The object passed into the input json parameter often comes from a response to a query operation in the REST API or a toJSON() method from another ArcGIS product. See the Using fromJSON() topic in the Guide for details and examples of when and how to use this function.

Parameter

json Object A JSON representation of the instance in the ArcGIS format. See the ArcGIS REST API documentation for examples of the structure of various input JSON objects.

Returns

Type	Description
*	Returns a new instance of this class.

hasHandles(groupKey){Boolean}inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Returns true if a named group of handles exist.

Parameter

groupKey * optional A group key.

Returns

Type	Description
Boolean	Returns true if a named group of handles exist.

Example

// Remove a named group of handles if they exist.
if (obj.hasHandles("watch-view-updates")) {
  obj.removeHandles("watch-view-updates");
}

removeHandles(groupKey)inherited

Since: ArcGIS Maps SDK for JavaScript 4.25

Removes a group of handles owned by the object.

Parameter

groupKey * optional A group key or an array or collection of group keys to remove.

Example

obj.removeHandles(); // removes handles from default group

obj.removeHandles("handle-group");
obj.removeHandles("other-handle-group");

toJSON(){Object}

Converts an instance of this class to its ArcGIS portal JSON representation. See the Using fromJSON() guide topic for more information.

Returns

Type	Description
Object	The ArcGIS portal JSON representation of an instance of this class.