Using Elevation Services in ArcGIS Pro

Topics in this section:

Adding and using the elevation services in ArcGIS Pro

Please add the elevation services in ArcGIS Pro as described above in sections https://spatial-qld-support.atlassian.net/wiki/spaces/img/pages/62588607 and https://spatial-qld-support.atlassian.net/wiki/spaces/img/pages/62588639.

It is advised to use the dynamic Time Series elevation services in ArcGIS Pro, and not the tile_cached services like the QldDem and QldDem_clp_users, because they do not display in ArcGIS Pro, however in ArcMap they do.

The dynamic elevation services contain rendering functions. To apply the function templates such as Aspect, Hillshade, Slope in Degrees or Slope Percent_rise to the them (note, there are no templates on tile_cached services), right-click  on the elevation layer and open the Properties -> Processing Templates. Choose a function from the Processing Template dropdown menu then Apply and OK.  Select the function via processing templates:


Application of Elevation Services in GIS Analysis 

Elevation services provide a baseline for the GIS analyses and visualisations that support many common GIS elevation tasks. In many maps and GIS applications it is used as a base height source. Some basic uses of elevation services are explained below with examples.

Extracting Height Information at a Point  

To obtain height information at a point you must first set Processing Templates to None in the Layer Properties.  Right-click on the elevation service in the Contents pane, then click Properties -> Processing Templates and select None:

To obtain the height at a location use Identify by holding down the 'C' key on your keyboard to temporarily activate the Identify Explore tool and click on a location on the map.

 

A pop-up window appears which returns elevation value at that point. If more than one height source is available, then the returned Service Pixel Value will be from the highest resolution DEM.

In this example two elevation datasets were available, and the Service Pixel Value returned is from Gympie_2009_Rgn because it has the highest resolution of the two. 

 


Viewing and Performing Raster Analysis 

Some simple raster analysis can be performed and viewed using the Elevation Service as a layer. To add an individual project from an image service as a layer follow the instructions below.

  • Open the attribute table of the Image Service 

  • Select a single project to use for Image Analysis 

  • Select the Elevation Service layer in the Contents pane

  • In the Image Service Layer ribbon click on Data -> Operations -> Add to Map. Give it the name of the project in the pop-up window Group layer name and OK:

  • Another option is to use the Explore Raster Items in the Image Service Layer ribbon under the Data tab. The Raster Item Explorer window opens on the right.  Under the Preview window click on the plus sign for the Add to Current Map option:


Convert 2D features into 3D features

 It is often useful to have features with 3D geometry. Although you can display 2D features by draping them over a surface, 3D features are displayed more rapidly and they can be shared with others without having to send along the surface data.  There are also many 3D analytic operations that can take advantage of 3D geometry, including complementary technologies such as the ArcGIS Network Analyst extension. Using elevation services 2D features can easily be converted into 3D features. There are two geo-processing tools in ArcGIS Pro that allow you to obtain 3D properties from a surface: Interpolate Shape and Add Surface Information.

Both of these tools require an ArcGIS 3D Analyst extension license and can be found in the Functional Surface toolset in the 3D Analyst Toolbox.

In ArcGIS Pro (at version 2.4.2) it is not possible to convert Graphics to Features (yet), therefore you need to convert a 2D polyline feature to a 3D polyline feature using the Interpolate Shape tool.

 


Generating Contours Dynamically Using Elevation Service

There is a Raster Function in ArcGIS Pro named Contour which can be used to generate contours dynamically from an Elevation Service. Although the resulting contours are in raster format it looks cartographically appealing. To generate contours dynamically follow the steps below:

Under the Analysis tab choose the Raster Functions in the ribbon.  

 

In the Raster Functions window select Contour Function  which is located under the Surface group. 

 

 

 

 

Fill in the parameters required by this tool to generate contours.  You can use the Lidar Project or the full elevation service

 


Raster Image Draped on Elevation Service 

Any raster image can be viewed in 3D by draping it over an elevation service layer. In ArcGIS Pro this can be done by inserting a Scene. In the Contents pane under Elevation Surfaces right click on Ground, choose Add Elevation Source, and Search for one of our Queensland DEM services via the Spatial Portal -> All Portal.


Integrating Hillshade into 2D Maps to Make it Stunning  

If you place a Hillshade layer underneath the existing 2D layers in your map, it gives viewers the impression of 3D. The example below shows a Topographic map sourced from the Department of Resources QTopo application. A Hillshade layer has been placed beneath the other layers and gives visual emphasis to the contours:  

In the new elevation services, embedded raster functions as Processing Templates are available enabling visualisation of the DEM Hillshade dynamically. Users can use Hillshade in maps or models to make them look more realistic.

Right-click on the elevation service in the Contents pane in a 2D ArcGIS Pro Map to open its Layer Properties and under the Processing Templates tab choose the Hillshade function and OK:


Aspect and Slope 

As mentioned above in the Elevation services raster functions are embedded within the service. Using these processing templates, when the service is in a dynamic state with the tile_cache turned off, users can visualise DEM as Aspect and Slope as well. With this provision, the Elevation service will be applicable and consumable by many more applications. If users need to visualise these several products they can easily switch between templates. 


Extract an Elevation Profile of a Line 

Profile Graphs allow you to visualise elevation change over a continuous distance using 3D line geometry. In ArcGIS Pro a profile graph can be made for any 3D line layer in the Map Contents pane.  If you do not have an existing 3D line layer use the Interpolate Shape tool in conjunction with the Elevation Service to convert a 2D polyline to a 3D polyline layer.

Then use the 3D Analyst extension Stack Profile tool from the 3D Analyst Function Surface toolset:

 

 

An Elevation Profile can be created by right clicking on the Output Table from the Stack Profile tool in the Contents pane and choosing Create Chart -> Line Chart.

On the right the Chart Properties pane opens. Configure the chart specifying FIRST_DIST field as the Horizontal Distance on the x axis under the Data tab:

 

FIRST_Z field as the Elevation on the y axis under the Series tab:

and finally adding titles under the General tab:


Visibility analysis 

What is visible from a location is an important element in determining the value of real estate, the location of telecommunications towers, or the placement of military forces. The shape of a terrain surface affects which parts of the surface someone standing at a given point can see. By using an elevation service layer you can easily check visibility from a point to its surroundings. The Line of Sight tool in ArcGIS Pro can be used to check visibility from a point: 


Cut and Fill 

If your map contains an elevation service layer, you can easily perform cut and fill analysis. In ArcGIS Pro the Cut and Fill tool can be used to calculate cut and fill on the existing terrain surface determined by another plane surface drawn on the map.


Viewshed Analysis

A viewshed is the area visible from a specific location.  This analysis uses the elevation value of each cell from a DEM (digital elevation model) to determine the visibility from a particular cell or observation. Viewshed analysis is used to determine visibility to and from particular observation locations. Some examples may include determining visibility from roads, trails and fire observation stations.

In ArcGIS Pro there are several toolboxes that contain Viewshed tools:

·        Ready to Use – Elevation toolset

·        Spatial Analyst – Surface toolset

·        3D Analyst – Visibility toolset

 An example output image of a Viewshed analysis:


Hydrological Analysis

The use of a Digital Elevation Model (DEM) elevation in hydrology is very well established. Many hydrological analyses require an accurate DEM as an input; examples include watershed delineation, flood modelling, stream network extraction, river catchment delineation and flow modelling. Authorities responsible for performing hydrological analysis can use elevation services to perform GIS analysis on demand using the Hydrology toolset available in the Spatial Analyst toolbox in ArcGIS Pro.  


Rendering Rules

In addition to applying Processing Templates functions in the Properties of the DEM dynamic services, Rendering Rules can be applied via the Imagery ribbon in ArcGIS Pro to all elevation services.

  • In ArcGIS Pro add a DEM service as described in sections https://spatial-qld-support.atlassian.net/wiki/spaces/img/pages/62588607 and of this document.

  • Choose the Hillshade icon for example, and in the tool the service in the dropdown, then make the following adjustments - Azimuth = 315; Altitude = 45; Z Factor = 2.5.  Click Create new layer which add a new function layer to the Contents:

  • Choose the Hillshade icon for example, and in the tool the service in the dropdown, then make the following adjustments - Azimuth = 315; Altitude = 45; Z Factor = 2.5.  Click Create new layer which add a new function layer to the Contents:


Export Elevation Service Data for offline use

There are different options to clip, extract, or export from an elevation service:

Export Raster

You can export a tiff file from a Dynamic elevation service for offline use in the field and still obtain the height value of the topmost project in the service.

  • In ArcGIS Pro add a tile_cached (make sure to turn the tile_cache off), or dynamic elevation service to the TOC and make sure to apply the DRA via the Appearance tab in the Imagery Service Layer ribbon.

  • Zoom in to the area of interest.

  • Right click on the service layer in the TOC  -> Data -> Export Raster, which opens the Export Raster pane and apply the following settings:

    • Clipping Geometry:  Current Display Extent (which automatically open the Top, Right, Bottom, Left values)

    • Maintain Clipping Extent

    • Output Format: Tiff or Img

    • Check Cell Size

    • Check Raster Size – if too many Columns and Rows you may need to zoom in further. 
      It will also throw a warning when there are too many Columns and Rows.
      It doesn’t give the output file size like ArcMap does.

    • Export

  • It automatically adds the exported layer to the Contents. The exported tiff is accompanied by a .tfw world file.

  • Click with the mouse in the display, which opens up the Pop Up pane with the height value of the cell.  It will be the height value of the topmost project in the service.

 

 

 

 

 

 

Make Image Service Layer

You can also run the tool, “Make Image Service Layer”, with a query and/or Mosaic Method if you want, which will create a temporary layer in the Contents:

From which you can Clip Raster which allows you to create a bigger area than the Export Raster above, but creates a bigger file size for uploading onto field devices.

Or “Extract by Mask” (needs Image Analyst license) using an AOI polygon layer for Input raster or feature mask data in the Parameters:

Use the AOI for Mask and Processing Extent as well as applying LERC compression in the Environments