Processing report

Every ArcGIS Drone2Map project includes a detailed processing report that displays the results of the block adjustment. Block adjustment is the process of computing an adjustment or transformation based on the internal relationship between overlapping images, control points, a camera or sensor model, and a digital elevation model (DEM). After performing a block adjustment, it is necessary to review the results of the adjustment and assess the quality of the control points (ground control points [GCPs], tie points, and checkpoints) used in the adjustment.

To access the report once the initial processing step is completed, on the Home tab, in the Processing section, click Report. You can also access the processing report at any time in the project folder in PDF and HTML format. The processing report includes the following sections:

Project Summary

The Project Summary table provides an overview of general project settings . The fields in the Project Summary table are described below:

Field nameDescription

Project Name

Name of the ArcGIS Drone2Map project.

Processed On

Date and time the report was generated.

Camera Model

Drone camera model used in processing.

Images

Number of images used in the block adjustment.

Project Area

Size of the project area used in processing.

Ground Resolution (m/pixel)

Average ground resolution for all images in the image collection. The units are listed in the field heading.

Processing Time

Total time elapsed to process the project.

Adjust Images

The Adjust Images section provides a synopsis of the settings used for the block adjustment process and the quality of the adjustment.

Summary

The adjust images Summary table provides a synopsis of your most recent block adjustment. The fields in the Adjust Images Summary are described below:

Field nameDescription

Number of Tie Points

Number of tie points used to perform the block adjustment.

Number of Solution Points

Number of solution points generated in the block adjustment.

Mean Reprojection Error / Sigma Naught (Pixel)

The root mean square error (RMSE) of the reprojection across all adjusted images. The units are pixels.

Each computed 3D point has initially been detected on the images (2D keypoint). On each image, the detected 2D keypoint has a specific position. When the computed 3D point is projected back to the images, it has a reprojected position. The distance between the initial position and the reprojected one gives the reprojection error for the tie point.

Ground Control Points RMSE (m)

The root mean square error (RMSE) of each ground control point used in the adjustment. The units are meters.

Initial Processing Time

Amount of time taken to complete the initial processing step.

Processing Options

The Processing Options table within the Adjust Images section lists the user-defined settings used in the adjustment process. The fields in Processing Options are described below:

Field nameDescription

Initial Image Scale

The image scale used to extract feature points for adjustment

Refine Adjustment Scale

The image scale used when the refine adjustment option is enabled

Matching Neighborhood

Size of the neighborhood used to find tie points during adjustment

Internal Camera Parameters

The Internal Camera Parameters table lists the camera calibration information for the adjustment. The information is derived from the camera database when you load your project imagery. The camera calibration parameters can be modified in the Edit Camera Parameters pane by using the Edit Camera button on the Flight Data ribbon.

Edit Camera Parameters pane

The Internal Camera Parameters table is split into two fields: initial camera parameters that are used for adjustment and the optimized camera parameters that are calculated after the block adjustment completes.

The fields in the Internal Camera Parameters table are described below:

Field nameDescription

Focal Length (mm)

Camera lens focal length in millimeters.

Principal Point X (mm)

The principal point is a point on the image plane where a line from perspective center (camera lens), perpendicular to the image plane, intersects the image plane. The X direction is parallel to the direction of image rows.

Principal Point Y (mm)

The principal point is a point on the image plane where a line from perspective center (camera lens), perpendicular to the image plane, intersects the image plane. The Y direction is parallel to the direction of image columns.

K1, K2, K3, P1, P2

Lens distortion parameters, defined by the Brown-Conrady Model.

Reference: Qi, J. et al., 1994, "A modified soil vegetation adjusted index," Remote Sensing of Environment, Vol. 48, No. 2, 119–126.

Tie Points Per Image

For every adjusted image, a number of tie points were used to perform the adjustment. The fields in the Tie Points Per Image table are described below:

Field nameDescription

Min

Minimum number of tie points used in an image adjustment for the image collection

Max

Maximum number of tie points used in an image adjustment for the image collection

Median

Median number of tie points used per image adjustment for the image collection

Average

Average number of tie points used per image adjustment for the image collection

Total

Total number of tie points used in the image adjustment for the image collection

Tie Point Projection Error

This table lists the various reprojection error statistics for tie points generated from the project imagery. The fields in the Tie Point Projection Error table are described below:

Field nameDescription

Min (Pixels)

Image with the lowest tie point reprojection error. The image file name is listed and units are in pixels.

Max (Pixels)

Image with the highest tie point reprojection error. The image file name is listed and units are in pixels.

Median (Pixels)

Median reprojection error for tie points across all project imagery. The units are pixels.

Average (Pixels)

Average reprojection error for tie points across all project imagery. The units are pixels.

Standard Deviations of Exterior Orientation

This table lists the standard deviations for solution point GPS and orientation. The table is split into the minimum and maximum deviations for all solution points. The values can provide a rough gauge of solution point accuracy with lower values being preferable. GPS positions are measured in meters and orientation values are measured in degrees. The fields in the Standard Deviations of Exterior Orientation table are described below:

Field nameDescription

X (m)

Solution point shift in the X direction. The units are meters.

Y (m)

Image shift in the Y direction from the initial position. The units are meters.

Z (m)

Image shift in the Z direction from the initial position. The units are meters.

Omega (degrees)

Image rotational angle shift of the camera's x-axis. The units are decimal degrees.

Phi (degrees)

Image rotational angle shift of the camera's y-axis. The units are decimal degrees.

Kappa (degrees)

Image rotational angle shift of the camera's z-axis. The units are decimal degrees.

Adjusted Image Positions

The Adjusted Image Positions graphic shows a representation of the GPS deviations for each image before and after block adjustment. Blue points indicate the initial position of the images from the GPS, and green points indicate the GPS location as a result of adjustment. The vectors are exaggerated for visualization. When viewing this graphic, assess the directional shift of the images in your image collection to evaluate systematic error in the adjustment.

Overlap Map graphic

The Overlap Map graphic is a static map of the overlap between images. Higher numbers of overlapping images produce higher accuracy for three-dimensional ortho products. You can use this graphic to identify areas in your image collection that may require additional overlap, or to better understand the accuracy of your adjustment.

Cross Matches graphic

The Cross Matches graphic indicates the level of connection between images. A link with a dark color indicates a larger number of tie point sets and a stronger connectivity between the images. Identify areas in your image collection where tie points are sufficient or lacking, and use this information to add control points or overlapping images if necessary.

Solution Points table

Tie points connecting two or more image links are essential for aerial triangulation. The Solution Points table lists the number of times a solution point is detected and linked in other images. The 2 Images field represents the number of solution points that connect at least two overlapping images. Similarly, the 3 Images field represents the number of solution points that connect three overlapping images, and so on. Adjustment quality is better when there is a large number of solution points that have high overlap between images.

Geolocation Details

The Geolocation Details section of the processing report provides adjustment details on any ground control points that were used in the project.

Ground Control Points

The Ground Control Points table shows an overall summary of the GCPs used in the block adjustment. It is only listed in the report if you used GCPs in the adjustment. Each ground control point will be listed in the table as its own field along with adjustment statistics for the point. The fields in the Ground Control Points table are described below:

Field nameDescription

<Ground Control Point name>

Name of the ground control point used in the adjustment. Statistics for each point include its shift after adjustment from its initial X (dX), Y (dY), and Z (dZ) position in meters. Projection Error for each point is listed in pixels. Status lists the number of valid versus total image links used for that ground control point.

RMSE

The root mean square error (RMSE) of all ground control point used in the adjustment. Values are provided for the points X (dX), Y (dY) and Z (dZ) position and units are in meters.

Min

The minimum amount of shift in either X (dX), Y (dY), or Z (dZ) position between all ground control points. Units are in meters.

Max

The maximum amount of shift in either X (dX), Y (dY), or Z (dZ) position between all ground control points. Units are in meters.

Median

The median amount of shift in either X (dX), Y (dY), or Z (dZ) position between all ground control points. Units are in meters.

Average

The average amount of shift in either X (dX), Y (dY), or Z (dZ) position between all ground control points. Units are in meters.

Dense Matching

The Dense Matching section of the processing report provides information on point cloud settings and generation.

Summary

This table lists the point cloud settings used in the project to derive the level of geometric detail of the resulting reconstruction. The fields in the Summary table are described below:

Field nameDescription

Point Cloud Density

The level of density of the point cloud used in the project

Number of Tiles

Number of tiles the point cloud was divided into when generated

Processing Time

Total time taken to run the Dense processing step

Project settings

The project settings section of the processing report includes information about the system the project was processed on, coordinate systems used within the project, project resolution and whether any preprocessing was used. These sections are described further below:

System information

System hardware and operating system information are listed for each project. Hardware information is displayed as the system's CPU, RAM, and GPU. More information on supported hardware in ArcGIS Drone2Map can be found under system requirements.

Coordinate information

Coordinate systems used in the project are listed in this section. The table is broken into the coordinate system used for the images, project, and ground control points. If there are no ground control points in the project, that field will not appear.

Project resolution

The project resolution used to process all projects. This is defined within the processing options and defaults to different levels depending on the template in use.

Pre--processing

The preprocessing table provides an answer to whether preprocessing adjustments were used in processing of the project. A Yes or No is provided for each of the preprocessing options.

2D products

The 2D products section of the processing report provides a summary of product processing times and 2D processing options enabled on the project.

Summary

The 2D Products Summary table lists each of the products that were enabled for processing and the total time it took to generate them. A field for a 2D product will only appear if it is enabled when processing completes.

Processing Options

The 2D Products Processing Options table lists the 2D products and options available and whether they were enabled or disabled for processing. A Yes or No is provided for each of the processing options.

3D products

The 3D products section of the processing report provides a summary of 3D processing options enabled on the project.

Processing Options

The 3D Products Processing Options table lists the 3D products and options available and whether they were enabled or disabled for processing. A Yes or No is provided for each of the processing options.