An alignment report displays the statistical results of an alignment. After an alignment is made, you can assess the alignment results before creating the report to ensure that it meets acceptance criteria.
An alignment report includes the quality of the control points (ground control points and check points) and tie points (automatic and manual) used in the alignment.
Save an alignment report
Once the alignment is processed, you can create an alignment report.
To create an alignment report, complete the following steps:
- In the Project Tree pane, click the alignment you want to create a report for.
- On the Alignment tab, click
Report.
The Create Alignment Report dialog box appears.
- Browse to a valid location and type a name for the report.
- Click Save.
The alignment report is created as a .pdf file in the specified location.
Alignment report tables
The alignment report includes several tables which are described below.
General Information
The General Information table provides an overview of the general project settings and contains the following fields:
| Field name | Description |
|---|---|
Alignment Name | The name of the alignment. |
Number of Images | The number of images in the alignment. |
Camera Sessions | The number of camera sessions in the alignment. |
Coverage Area | The area covered by the images in the alignment. |
Sigma 0 | An overall evaluation of the quality of all point image measurements in the alignment. |
Flight Mission Statistics
The Flight Mission Statistics table lists various statistics of the general flight missions data used in the alignment and contains the following fields:
| Field name | Description |
|---|---|
Flying Height | The flying height above the ground registered in the alignment. |
Terrain Height | The terrain height information registered in the alignment. |
GSD | The ground sampling distance registered in the alignment. |
Count
The Count table lists various data counts of the control points and tie points used in the alignment and contains the following fields:
| Field name | Description |
|---|---|
Ground Control Points | The number of ground control points in the alignment. |
Check Points | The number of check points in the alignment. |
Automatic Tie Points | The number of automatic tie points in the alignment. |
Manual Tie Points | The number of manual tie points in the alignment. |
Reprojection Errors
The Reprojection Errors table lists various reprojection error statistics for points used in the alignment and contains the fields described below.
Note:
Each 3D point is calculated using 2D image measurements. The image measurements are used to triangulate the estimated 3D position of the measured point. The reprojection error is the 2D distance (in pixel units) between the projection of the original 3D point onto an image and the back projection of the triangulated point.
| Field name | Description |
|---|---|
Ground Control Points | The residuals of the ground control points image measurements used in the alignment. |
Check Points | The residuals of the check points image measurements used in the alignment. |
Manual Tie Points | The residuals of the image measurements used to measure manual tie points in the alignment. |
Automatic Tie Points | The residuals of the image measurements used to measure automatic tie points in the alignment. |
3D Residuals-Control Points
The 3D Residuals-Control Points table lists various error statistics of the control points used in the alignment and contains the fields described below. This table is included in the report if you used control points in the alignment. A 3D residual of a control point is the difference between its calculated 3D coordinate in the alignment and the original 3D coordinate. The control points residual units are expressed in object space.
| Field name | Description |
|---|---|
Ground Control Points | The residuals of the ground control points used in the alignment. |
Check Points | The residuals of the check points used in the alignment. |
3D Residuals-Camera Poses
The 3D Residuals-Camera Poses table lists various error statistics of the exterior orientations parameters (X, Y, Z, omega, phi, kappa) used in the alignment. The 3D residual of a camera pose is the difference between its calculated orientation in the alignment and the original orientation. The camera pose residuals are expressed in object space and divided into position residuals and rotation residuals. Camera position residuals refer to the difference in 3D coordinates (X, Y, Z) in their respective spatial reference. Camera rotation residuals refer to the difference in rotation angles (omega, phi, kappa) in radians units.
| Field name | Description |
|---|---|
Camera Positions | The residuals of the image positions used in the alignment. |
Camera Rotations | The residuals of the image rotations used in the alignment. |
Global Shift and Misalignments
The global shift is a common translation applied to all camera poses with respect to the world coordinate system.
The leverarm misalignment is the error attributed to the translation vector between the GPS/GNSS antenna and the camera system (single or multi head). Typically the reference point is chosen as the perspective center of the nadir frame.
The boresight misalignment is the rotational offset between the IMU device and the camera system (single or multi head). It is assumed that the measurements of the IMU describe the rotation at the position of GPS/GNSS antenna.
| Field name | Description |
|---|---|
Global Shift | The translation applied to all camera poses. |
Leverarm | The leverarm misalignment. |
Boresight | The boresight misalignment. |