Available with Advanced license.
Computing the photogrammetric solution for an aerial image 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. For scanned images, the image interior orientations are also affected by the fiducials and how the aerial photographs are scanned.
Processing scanned aerial images depends on the quality of the initial EO and IO you can provide for your frames and camera information. For the EO, you must provide image names, perspective points (x, y, z), and Omega, Phi, and Kappa in a tabular form or an Esri Frames Table. For the IO, if the camera calibration report is available for the images that you are processing, you can find the required camera parameters such as focal length, pixel size, principal point, lens distortion, and the fiducial film coordinates of the camera. If some of the camera calibration information is not available, the utilities for scanned images can help you automatically estimate some of the required parameters in the frames table or cameras table. Refer to the Historical Imagery webpage to download tools and workflows for processing scanned aerial photographs.
The workflow for creating the interior and exterior orientation depends on the metadata that is available with your scanned images. For example, if you already have a description of the camera model and a table that describes the x,y,z location and Omega, Phi, and Kappa orientation of each image file, you can use the Ortho Mapping Workspace wizard to create the cameras table that defines the camera model and IO, as well as the frames table that defines the exterior orientation of the images. These tables can also be prepared before creating your workspace using the Build Frame and Camera Tables tool. The two tables can be in a .csv format or as ArcGIS supported tables; see Frames table schema and Cameras table schema for more information.
If you have more limited metadata, such as no estimates for Omega, Phi, Kappa or limited metadata regarding the camera model, then creation of the cameras and frames tables in a format usable by ArcGIS may require a more manual process. Refer to the Historical Imagery webpage to download tools and workflows for processing historical imagery. The type and quality of your metadata will determine characteristics of your ortho mapping workspace for scanned aerial imagery, and the quality of your ortho mapping products. For example, if you do not provide fiducial information, you cannot refine the interior orientation. You can estimate fiducial information to produce a fiducial template used to refine your interior orientation and produce improved ortho mapping products. The processing capabilities supported by different levels of metadata information are summarized in the table below.
- 0 means that Phi and Omega are required, but you can provide a value of 0 (zero).
- The film fiducial information can be estimated from the camera's film coordinates if a formal calibration report is not available.
Create an ortho mapping workspace for scanned aerial imagery
- On the Imagery tab, click New Workspace.
- On the Workspace Configuration page, type a name for your workspace.
- Use the Workspace Type drop-down arrow to choose Aerial - Scanned.
- Click Next.
- On the Image Collection page, specify the Exterior Orientation File / Esri Frames Table file. This table, in .csv format, enables specification of parameters that compute the exterior orientation (EO) of your imagery.
If you input an Exterior Orientation File that is not an Esri Frames Table file, the Frames page will open for you to input field mapping information.
- The Frame Spatial Reference parameter will be automatically set by the spatial reference of the perspective points defined in the Esri Frames Table. If the Frame Spatial Reference parameter is not specified, click the Spatial Reference icon to set the spatial reference to be the same coordinate system as the perspective points.
- Specify the Cameras table file. This is the .csv file that contains the camera configuration information.
If you Add a camera , or Import a camera file that does not conform to the camera table schema, the Add New Camera page will open for you to enter the camera information. The Calibration tab on the Add New Camera page is where you enter the camera information, usually available from the manufacturer.
Use the Distortion tab to enter the camera distortion information, if available. This type of information is often available in the camera calibration report when your mapping camera is calibrated.
You can use the Export button on the Source Data Properties tab to store the camera calibration parameters as an Esri Cameras Table for future use.
- Specify a Spatial Reference for your workspace, which applies to your image collection and ortho mapping products to be generated.
- If the various inputs comprising your workspace have different coordinate systems, you can specify a common map projection system by clicking on the Edit button . The Coordinate System Transformations dialog appears where you can choose a coordinate system from the Select Transformation drop-down list, and specify Geographic Transformations.
- Optionally, click the Data Loader Options tab to further refine your output workspace.
- Creating an ortho mapping workspace from aerial imagery needs
elevation data. The DEM parameter wizard provides an elevation service with a 90 meter resolution by default. You can use a different DEM service or file by navigating to it. Choose your Elevation Source.
- If you have access to the Internet, use the default elevation service for the DEM parameter, and Average Elevation from DEM for the Elevation Source option.
- If you do not have access to the internet, provide a DEM file covering the project area, and choose Average Elevation for the Elevation Source option.
- Check the Estimate Statistics check box to estimate the statistics for your output workspace.
- Edit the Band Combination parameters, if you want to reorder the band combination from the default order.
- Choose either of the Pre-processing options to Calculate Statistics or Build Pyramids on your data before your create your workspace.
- Creating an ortho mapping workspace from aerial imagery needs elevation data. The DEM parameter wizard provides an elevation service with a 90 meter resolution by default. You can use a different DEM service or file by navigating to it. Choose your Elevation Source.
- Click Finish to create the workspace.
When the ortho mapping workspace is created, the image collection will be loaded in the workspace and displayed on the map. You are now ready to perform adjustments and generate ortho products.