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Tutorial: Create 2D digital aerial imagery products in ArcGIS Reality for ArcGIS Pro

In this topic

  1. Create a Reality mapping workspace
  2. Perform a block adjustment
  3. Generate Reality mapping products
  4. Summary

Available with Standard or Advanced license.

Available for an ArcGIS organization with the ArcGIS Reality license.

In ArcGIS Pro, you can correct digital aerial imagery collected by a professional mapping camera using photogrammetry to remove geometric distortions caused by the sensor and correct for terrain displacement. After correcting these effects, you can generate Reality mapping products.

In this tutorial, you will set up a Reality mapping workspace to manage an aerial imagery collection. You will perform a block adjustment and review the results. Then you'll generate digital surface model (DSM), true ortho, and 2D DSM mesh products.

Computing the photogrammetric solution for aerial imagery is determined by its exterior orientation (EO), which represents a transformation from the ground to the camera and its interior orientation (IO), which represents a transformation from camera to image. Required EO parameters include perspective center (x,y,z) coordinates, and omega, phi, and kappa angles are provided in a frames table. Interior orientation parameters include focal length, pixel size, principal point, and lens distortion. This information is available in the camera calibration report associated with the imagery and must be provided in a camera table.

License:

The following licenses are required to complete this tutorial:

  • ArcGIS Reality Studio
  • ArcGIS Pro 3.1 or later
  • ArcGIS Reality for ArcGIS Pro extension setup

Create a Reality mapping workspace

A Reality mapping workspace is an ArcGIS Pro subproject that is dedicated to Reality mapping workflows. It is a container in an ArcGIS Pro project folder that stores the resources and derived files that belong to a single image collection.

A collection of digital aerial images is provided for this tutorial. The tutorial data also contains frame and camera tables.

To create a Reality mapping workspace, complete the following steps:

  1. Download the tutorial dataset and save it to C:\SampleData\Aerial Imagery.

    If you save the data to a different location on your computer, update the path in each of the entries in the Nadir_FramesCam.csv file.

    1. Unzip the package in the C:\SampleData\Aerial Imagery directory.
  2. In ArcGIS Pro, create a project using the Map template and sign in to your ArcGIS Online account.

    The default Parallel Processing Factor value is 50%. To accelerate the adjustment process, you can increase this value.

  3. On the Analysis tab, click Environments, and in the Environments window, change the Parallel Processing value to 80%.
  4. On the Imagery tab, in the Reality Mapping group, click the New Workspace drop-down menu and choose New Workspace.
  5. In the Workspace Configuration window, provide a name for the workspace.
  6. Set Workspace Type to Reality Mapping.
  7. In the Sensor Data Type drop-down menu, choose Aerial - Digital.
  8. Set Scenario Type to Nadir.

    This setting is recommended when working with nadir imagery.

  9. In the Basemap drop-down menu, choose Topographic.

    Workspace Configuration window

  10. Accept all the other default values and click Next.
  11. In the Image Collection window, under Exterior Orientation File / Esri Frames Table, browse to the tutorial data folder on your computer and the Nadir_FramesCam.csv frames table file.

    This table, which contains the frames and cameras information, specifies parameters that are used to compute both the IO and EO for the camera and the imagery. In the block adjustment process, these approximate values are refined for greater accuracy.

    Ensure that the data paths listed in the raster column in the frame table file match the location of the image files on your computer.

  12. Under Cameras, click the Import button Import, browse to the tutorial data folder on your computer, and select the Nadir_FramesCam.csv file .
    13. For this tutorial, the Esri frame and camera tables are provided as a single file in the proper format. For other datasets, you may need to build and format the tables. For more information, see Frames table schema.
  13. Ensure that the Spatial Reference and camera model values are correct.

    The default projection for the workspace is defined based on the imagery. This projection must match the coordinates used in the frames table, and it determines the spatial reference for the Reality products you create. For this dataset, you’ll use the projection defined in the frames and cameras table: XY – NAD83 2011 StatePlane California V FIPS 0405, VCS NAVD88 (meters).

  14. Accept the other default values and click Next.

    Image Collection window

  15. In the Data Loader Options window, under DEM, click the browse button, browse to the tutorial data folder on your computer, and select the DEM_USGS_1m.tif file.
  16. Accept the other default values and click Finish.

    Data Loader Options window

Once you create the workspace, the images and image footprints display. The Reality Mapping category has also been added to the Contents pane. The source imagery data and derived Reality mapping products will be referenced here.

The initial display of imagery in the workspace confirms that all images and necessary metadata were provided to initiate the workspace. The images have not been adjusted, so the alignment is only approximate at this time, and the mosaic may not look correct.

Image Collection

Perform a block adjustment

After you create the Reality mapping workspace, the next step is to perform a block adjustment using the tools in the Adjust and Refine groups. The block adjustment will calculate tie points, which are common points in areas of image overlap. The tie points will then be used to calculate the orientation of each image, known as exterior orientation in photogrammetry.

To perform a block adjustment, complete the following steps:

  1. On the Reality Mapping tab, in the Adjust group, click Adjust Adjust.

    Perform Camera Calibration is not checked by default for digital aerial nadir imagery, as most airborne sensors have been calibrated and provide accurate interior orientation values in a camera calibration report. Automatic camera calibration is typically applied to other types of data, such as low-cost drone cameras, to compute and improve the camera’s geometric parameters while simultaneously determining image orientation and image ground coordinates.

  2. Accept the default values for all the settings and click Run.

    Adjustment settings

  3. After the adjustment is complete, turn on the Tie Points layer in the Contents pane to view the distribution of generated tie points on the map.

    Tie point distribution

    You can view tie point residuals and accuracy reporting in the logs file.

  4. On the Reality Mapping tab, in the Review group, click Logs View Logs View.

    Adjustment residual log file

    The units for tie point RMS error is pixels.

Review the adjustment results

After performing a block adjustment, review the adjustment results and assess the quality of the adjustment. On the Reality Mapping tab, in the Review group, click Adjustment Report to generate adjustment statistics. The adjustment report provides a record of the adjustment and overall quality measures of the process.

Tip:
Using ground control points (GCPs) to improve the absolute accuracy is a best practice. However, GCPs were not available and are not included in this adjustment.

Adjustment report

Generate Reality mapping products

Once the block adjustment is complete, 2D and 3D imagery products can be generated using the tools in the Product group on the Reality Mapping tab. Multiple products can be generated simultaneously using the Reality Mapping Products wizard or individually by selecting the applicable product tool from the Product group. The types of products that can be generated depends on various factors including the sensor, data flight configuration, and scenario type. The flight configuration of the sample dataset is nadir, which is ideal for 2D products such as DSM, true ortho, and DSM mesh.

Note:

In this tutorial, two approaches to generate derived products are described below. One approach uses the Multiple Products wizard and the second uses the individually named product wizards listed in the Product group. It is recommended that you follow one or the other workflow approach, since doing both workflows is not required for this tutorial.

Generate products using the Reality Mapping Multiple Products wizard

The Reality Mapping Products wizard guides you through the workflow to create one or multiple Reality mapping products in a single process. The products that can be generated using the Reality Mapping Multiple Products wizard are DSM, true ortho, DSM mesh, point cloud, and 3D mesh. All generated products are stored in product folders of the same name under the Reality Mapping category in the Catalog pane.

To generate products using the Reality Mapping Multiple Products wizard, complete the following steps:

  1. On the Reality Mapping tab, click the Multiple Products button in the Product group.

    The Reality Mapping Products Wizard window appears.

  2. In the Product Generation Settings pane, uncheck the 3D check box.

    In this tutorial, only 2D products are generated.

  3. In the 2D products category, uncheck Digital Terrain Model (DTM).

    DTM generation will be covered in a separate tutorial.

  4. Click the Shared Advanced Settings button.

    The Advanced Products Settings dialog box appears, where you can define parameters that will impact the Reality mapping products to be generated. For details of the advanced product settings, see Shared Advanced Settings option.

    The Quality and Scenario values are automatically set to Ultra and Nadir, respectively, and should not be changed to ensure optimum performance and product quality.

  5. Accept the Pixel Size default settings to generate products at source image resolution.
  6. Change the Forward Overlap (%) and Sideward Overlap (%) values to 80 and 60, respectively.
  7. For Product Boundary, click the Browse button Open folder connection, browse to the file geodatabase in the tutorial data location, select 2D_Pro_bdry, and click OK.

    It is recommended that you provide a product boundary for the following reasons:

    • Define the proper output extent—When you do not define a product boundary, the application automatically defines an extent based on various dataset parameters that may not match the project extent.
    • Reduce processing time—If the required product extent is smaller than the image collection extent, defining a product boundary reduces the processing duration and automatically clips the output to the boundary extent.

    Advanced settings for multiple products

  8. For Processing Folder, click the Browse button Open folder connection, and navigate to a location on disk that has a minimum available storage of 10 times the total size of the images being processed. In this case, 11 GB or more available storage.

    Note:
    The processing folder stores temporary files generated during Reality processing. It is recommended that the processing folder be located on a fast drive with large available storage space.

  9. Accept all the other default values and click OK.

    The Advanced Products Settings dialog box closes, and you return to the Product Generation Settings pane in the Reality Mapping Products wizard.

  10. Click Next to go to the DSM Settings pane, and ensure that the parameter values match the following:
    • Output Type—Mosaic
    • Format—Cloud Raster Format
    • Compression—None
    • Resampling—Bilinear
  11. Click Next to go to the True Ortho Settings pane, and ensure that the parameter values match the following:
    • Output Type—Mosaic
    • Format—Cloud Raster Format
    • Compression—None
    • Resampling—Bilinear
  12. Click Next to go to the DSM Mesh Settings pane, and ensure that the parameter values match the following:
    • Format—SLPK
  13. Click Finish to start the product generation process.

    Once product generation is complete, the DSM and true ortho products are automatically added to the 2D map view. In the Catalog pane, in the Reality Mapping container, the DSM mesh products are added to the Meshes folder, and the true ortho products are added to the Ortho folder.

You can end the tutorial now or continue to generate derived products using the individual product options in the Product group. If you continue, previously generated products will be overwritten. To maintain previously created products, follow the instructions in the Create a Reality mapping workspace section above to create a new Reality mapping workspace before proceeding.

Generate a DSM

To generate a DSM using the Reality Mapping Products wizard, complete the steps below.

Note:
Elevation values can be derived when the image collection has a good amount of overlap to form the stereo pairs. Typical image overlap necessary to produce point clouds is 80 percent forward overlap along a flight line and 60 percent overlap between flight lines.

  1. On the Reality Mapping tab, click the DSM button DSM in the Product group.

    The Reality Mapping Products Wizard window appears.

  2. Click Shared Advanced Settings.

    The Advanced Product Settings dialog box appears, where you can define parameters that will impact the Reality mapping products to be generated. For details of the advanced product settings, see Shared Advanced Settings option.

    The Quality and Scenario values are automatically set and should not be changed to ensure optimum performance and product quality. However, if you want to generate a reduced resolution product, the Quality value can be lowered. See Shared Advanced Settings for more information about the impact of various quality settings on product generation.

  3. Accept the Pixel Size default values to generate products at source image resolution.
  4. Change the Forward Overlap (%) and Sideward Overlap (%) values to 80 and 60, respectively.
  5. For Product Boundary, select a feature class identifying the output product extent from the drop-down list, or click the Browse button Open folder connection, browse to the file geodatabase in the tutorial data location, select 2D_Pro_bdry, and click OK.

    It is recommended that you provide a product boundary for the following reasons:

    • Define the proper output extent—When you do not define a product boundary, the application automatically defines an extent based on various dataset parameters that may not match the project extent.
    • Reduce processing time—If the required product extent is smaller than the image collection extent, defining a product boundary reduces the processing duration and automatically clips the output to the boundary extent.

  6. For Processing Folder, click the Browse button Open folder connection, and navigate to a location on disk that has a minimum available storage of 10 times the total size of the images being processed. In this case, 11 GB or more available storage.

    Note:
    The processing folder stores temporary files generated during Reality processing. It is recommended that the processing folder be located on a fast drive with large available storage space.

  7. Accept all the other default values and click OK.

    The Advanced Products Settings dialog box closes and you return to the Products Generation Settings pane in the Reality Mapping Products wizard.

  8. Click Next to go to the DSM Settings pane, and ensure that the parameter values match the following:
    • Output Type—Mosaic
    • Format—Cloud Raster Format
    • Compression—None
    • Resampling—Bilinear
  9. Click Finish to start the product generation process.

    Once processing is complete, the DSM product is added to the Contents pane, the Data Products category, and the 2D map view. It is also added to the Catalog pane, the Reality Mapping container, and the DEMs folder.

    Generated DSM

Generate a true ortho

One of the options in the Reality mapping Product group is True Ortho. A true ortho is an orthorectified image with no perspective distortion so that above-ground features do not lean and obscure other features. To create a true ortho, a DSM derived from the adjusted block of overlapping images is required. As a result, a DSM will be generated as a part of the true ortho process regardless of whether a DSM was previously selected as a product. The generated true ortho image will be stored in the Orthos folder under the Reality Mapping category in the Catalog pane.

To generate a true ortho using the Reality Mapping Products wizard, complete the following steps:

  1. On the Reality Mapping tab, click the True Ortho button True Ortho in the Product group.

    The Reality Mapping Products Wizard window appears.

  2. Click Shared Advanced Settings.

    The Advanced Product Settings dialog box appears, where you can define parameters that will impact the Reality mapping products that you generate. For a detailed description of the advanced product settings, see Shared Advanced Settings option.

  3. Complete steps 4 through 7 in the Generate DSM section above.
  4. Click Next to go to the True Ortho Settings pane, and ensure that the parameter values match the following:
    • Output Type—Mosaic
    • Format—Cloud Raster Format
    • Compression—None
    • Resampling—Bilinear
  5. Click Finish to start the product generation process.

    Once processing is complete, the true ortho product is added to the Contents pane, the Data Products category, and the 2D map view. It is also added to the Catalog pane, the Reality Mapping container, and the Ortho folder.

    Generated true ortho

Generate a DSM mesh

A DSM mesh is a 2.5D textured model of the project area where the adjusted images are draped on a triangulated irregular network (TIN) version of the DSM extracted from the overlapping images in the adjusted block. The Reality Mapping Products wizard simplifies the creation of the DSM mesh product by providing a streamlined workflow with preconfigured parameters. To create a DSM mesh product, a DSM derived from the adjusted block of overlapping images is required. As a result, a DSM is generated as a part of the DSM mesh generation process whether a DSM was selected as a separate product.

To generate a DSM mesh using Reality Mapping Products wizard, complete the following steps:

  1. On the Reality Mapping tab, click the DSM Mesh button DSM Mesh in the Product group.

    The Reality Mapping Products Wizard window appears.

  2. Click Shared Advanced Settings.

    The Advanced Product Settings dialog box appears, where you can define parameters that will impact the Reality mapping products that you generate. For a detailed description of the advanced product settings, see Shared Advanced Settings option.

  3. Complete steps 4 through 7 in the Generate DSM section above.
  4. Click Next to go to the DSM Mesh Settings pane, and ensure that the parameter values match the following:
    • Format—SLPK
  5. Click Finish to start the product generation process.

    Once processing is complete, the DSM mesh product is added to the Catalog pane, the Reality Mapping container, and the Meshes folder.

  6. To visualize the generated DSM mesh product, right-click the 3D_Mesh.slpk file in the Meshes folder, and from the drop-down menu, click Add to New > Local Scene.

    Generated DSM mesh

Summary

In this tutorial, you created a Reality mapping workspace for nadir digital aerial imagery and used tools on the Reality Mapping tab to apply a photogrammetric adjustment with ground control points. You used tools in the Products group to generate DSM, true ortho, and DSM mesh products. For more information about Reality mapping, see the following topics:

  • Reality mapping in ArcGIS Pro
  • Create a Reality mapping workspace for aerial imagery
  • Adjustment options for Reality mapping digital aerial imagery
  • Add ground control points to a Reality mapping workspace
  • Generate a DSM using ArcGIS Reality for ArcGIS Pro
  • Generate a True Ortho using ArcGIS Reality for ArcGIS Pro
  • Generate a DSM mesh using ArcGIS Reality for ArcGIS Pro

The imagery used in this tutorial was acquired and provided by Esri, Inc.

Related topics

  • Reality mapping in ArcGIS Pro
  • Perform a Reality mapping block adjustment
  • Adjustment options for Reality mapping satellite imagery
  • Manage tie points in a Reality mapping workspace
  • ArcGIS Reality mapping product generation
  • Generate a DSM using ArcGIS Reality for ArcGIS Pro
  • Generate a True Ortho using ArcGIS Reality for ArcGIS Pro
  • Generate a DTM using ArcGIS Reality for ArcGIS Pro
  • Create elevation data using the Ortho mapping DEMs wizard
  • Introduction to the ArcGIS Reality for ArcGIS Pro extension

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In this topic
  1. Create a Reality mapping workspace
  2. Perform a block adjustment
  3. Generate Reality mapping products
  4. Summary