Learn how to find the elevation for a point in Kaneohe, Hawaii with the ArcGIS Elevation service
The ArcGIS Elevation service
In this tutorial, use ArcGIS REST JS to access the Elevation service and display the elevation of a single location on a map. You can toggle between viewing elevation values relative to mean sea level or above ground level.
Prerequisites
You need an ArcGIS Location Platform account.
ArcGIS Online and ArcGIS Enterprise accounts are not supported.
Steps
Get the starter app
Select a type of authentication and follow the steps to create a new app.
Choose API key authentication if you:
- Want the easiest way to get started.
- Want to build public applications
A public application is an application that allows anonymous access without requiring users to sign in with an ArcGIS account. It supports API key or app authentication. that access ArcGIS Location ServicesArcGIS Location Services, also referred to as Location Services, are services hosted by Esri that provide geospatial functionality for developing mapping applications. They include the ArcGIS Basemap Styles service, ArcGIS Static Basemap Tiles service, ArcGIS Places service, ArcGIS Geocoding service, ArcGIS Routing service, ArcGIS GeoEnrichment service, and ArcGIS Elevation service. An ArcGIS Location Platform or ArcGIS Online account is required to use the services. and secure itemsAn item, also known as a content item, is a resource stored in a portal such as a web map, hosted layer, style, script tool, file, or notebook. . - Have an ArcGIS Location Platform or ArcGIS Online account.
Choose user authentication if you:
- Want to build private applications.
- Require application users to sign in with their own ArcGIS account
An ArcGIS account is an identity with a user type and set of privileges that can access specific ArcGIS products, tools, APIs, services, and resources. The main account types that can be used for development are an ArcGIS Location Platform account, ArcGIS Online account, and ArcGIS Enterprise account. ArcGIS Location Platform and ArcGIS Online accounts are also associated with a subscription. and access resources their behalf. - Have an ArcGIS Online account.
To learn more about both types of authentication, go to Authentication.
Set up authentication
Set developer credentials
Add script references
Reference the ArcGIS REST JS request and elevation packages to access the Elevation service. You also reference the Calcite Design System library to create the user interface.
-
Reference the
requestandelevationpackages from ArcGIS REST JS.Use dark colors for code blocks <script src="https://cesium.com/downloads/cesiumjs/releases/1.140/Build/Cesium/Cesium.js"></script> <link href="https://cesium.com/downloads/cesiumjs/releases/1.140/Build/Cesium/Widgets/widgets.css" rel="stylesheet"> <!-- ArcGIS REST JS --> <script src="https://unpkg.com/@esri/arcgis-rest-request@4/dist/bundled/request.umd.js"></script> <script src="https://unpkg.com/@esri/arcgis-rest-elevation@1/dist/bundled/elevation.umd.js"></script> -
Reference the Calcite Design System library.
Use dark colors for code blocks <script src="https://cesium.com/downloads/cesiumjs/releases/1.140/Build/Cesium/Cesium.js"></script> <link href="https://cesium.com/downloads/cesiumjs/releases/1.140/Build/Cesium/Widgets/widgets.css" rel="stylesheet"> <!-- Calcite --> <script type="module" src="https://js.arcgis.com/calcite-components/3.3.3/calcite.esm.js"></script> <link rel="stylesheet" href="https://js.arcgis.com/calcite-components/3.3.3/calcite.css"> <!-- ArcGIS REST JS --> <script src="https://unpkg.com/@esri/arcgis-rest-request@4/dist/bundled/request.umd.js"></script> <script src="https://unpkg.com/@esri/arcgis-rest-elevation@1/dist/bundled/elevation.umd.js"></script>
Update the map
In this step, you update the map by setting the viewpoint to focus on Kaneohe, Hawaii.
- To focus on Kaneohe, Hawaii, update the map's viewpoint to
-157.750, 21.380and set the scale to18055.Use dark colors for code blocks Copy viewer.camera.setView({ destination: Cesium.Cartesian3.fromDegrees(-157.750, 21.380, 18055), orientation: { heading: Cesium.Math.toRadians(0.0), pitch: Cesium.Math.toRadians(-80.0) } });
Get elevation data
In this step, you use the Elevation service to retrieve elevation data based on the clicked point on the map.
-
Create a variable called
elevationto store the default elevation reference (datum), which will beMeasure meanand add an event listener to your toggle to update theSea Level elevationaccordingly.Measure Use dark colors for code blocks /* Use for API key authentication */ const accessToken = "YOUR_ACCESS_TOKEN"; // or /* Use for user authentication */ // const session = await arcgisRest.ArcGISIdentityManager.beginOAuth2({ // clientId: "YOUR_CLIENT_ID", // Your client ID from OAuth credentials // redirectUri: "YOUR_REDIRECT_URI", // The redirect URL registered in your OAuth credentials // portal: "YOUR_PORTAL_URL" // Your portal URL // }) // const accessToken = session.token; Cesium.ArcGisMapService.defaultAccessToken = accessToken; const cesiumAccessToken = "YOUR_CESIUM_ACCESS_TOKEN"; Cesium.Ion.defaultAccessToken = cesiumAccessToken; const viewer = new Cesium.Viewer("cesiumContainer", { terrain: Cesium.Terrain.fromWorldTerrain(), timeline: false, animation: false, geocoder: false }); viewer.camera.setView({ destination: Cesium.Cartesian3.fromDegrees(-157.750, 21.380, 18055), orientation: { heading: Cesium.Math.toRadians(0.0), pitch: Cesium.Math.toRadians(-80.0) } }); let elevationMeasure = "meanSeaLevel"; document.getElementById("elevationControl").addEventListener("calciteSwitchChange", async (event) => { elevationMeasure = event.target.checked ? "meanSeaLevel" : "ellipsoid"; }); // Add Esri attribution const poweredByEsri = new Cesium.Credit("Powered by <a href='https://www.esri.com/en-us/home' target='_blank'>Esri</a>", true); viewer.creditDisplay.addStaticCredit(poweredByEsri); -
Create a function called
getthat takes longitude and latitude as parameters.Elevation Data Use dark colors for code blocks async function getElevationData(lon, lat) { } -
Make a request to the Elevation service, passing in the array of points.
Use dark colors for code blocks async function getElevationData(lon, lat) { const response = await arcgisRest.findElevationAtPoint({ lon: lon, lat: lat, relativeTo: elevationMeasure, authentication: arcgisRest.ApiKeyManager.fromKey(accessToken) }); } -
Add a click event handler on the map that calls the function and passes the selected point on the map as a parameter.
Use dark colors for code blocks viewer.screenSpaceEventHandler.setInputAction(function (movement) { const pickedPosition = viewer.scene.pickPosition(movement.position); const cartographic = Cesium.Cartographic.fromCartesian(pickedPosition); getElevationData(Cesium.Math.toDegrees(cartographic.longitude), Cesium.Math.toDegrees(cartographic.latitude)); }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
Display results
In this step, you extract the elevation data from the response and display it in a popup on the map.
-
Extract the
x,y, andzvalues from the elevation request response.Use dark colors for code blocks async function getElevationData(lon, lat) { const response = await arcgisRest.findElevationAtPoint({ lon: lon, lat: lat, relativeTo: elevationMeasure, authentication: arcgisRest.ApiKeyManager.fromKey(accessToken) }); const { x, y, z } = response.result.point; } -
Use
Entity()to show the elevation (zvalue) at the clicked location in a popup format.Use dark colors for code blocks async function getElevationData(lon, lat) { const response = await arcgisRest.findElevationAtPoint({ lon: lon, lat: lat, relativeTo: elevationMeasure, authentication: arcgisRest.ApiKeyManager.fromKey(accessToken) }); const { x, y, z } = response.result.point; let elevationInfo = `<b>Elevation relative to ${elevationMeasure === "meanSeaLevel" ? "mean sea level" : "ground level"}</b><br>Latitude: ${y.toFixed(5)}<br>Longitude: ${x.toFixed(5)}<br>Elevation: ${z} m`; let resultEntity = new Cesium.Entity({ name: "Elevation results", description: elevationInfo, position: Cesium.Cartesian3.fromDegrees(lon, lat) }); viewer.selectedEntity = resultEntity; }
Run the app
Run the app.
You should now see a map centered over Kaneohe, Hawaii. Click on the map to access the Elevation service to return elevation information and view the results in a popup.What's next?
Learn how to use additional location services in these tutorials:
