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 is divided into three sections: Summary, Input Data, and Alignment Results. Each section includes several tables, which are described below.
Summary
The Summary section includes general information about your alignment report. The following tables are in this section:
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 Capture Sessions | The number of capture sessions in the alignment. |
Number of Camera Sessions | The number of camera sessions in the alignment. |
Number of Images | The number of images in the alignment. |
Coverage Area | The area covered by the images in the alignment. |
Horizontal Coordinate System (WKID) | The horizontal coordinate system used in the alignment and its WKID designation. |
Vertical Coordinate System (WKID) | The vertical coordinate system used in the alignment and its WKID designation. |
Alignment Summary
The Alignment Summary table presents the results as global alignment metrics. Clicking the Jump to Section links take you to the section of the alignment report that provides additional information related to the metric shown.
Input Data
The Input Data section includes information on the data used to create your alignment, such as cameras and control points. The following tables are in this section:
Flight Mission Statistics
The Flight Mission Statistics table lists general flight missions data used in the alignment and contains the minimum, mean, and maximum values for 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. |
Project Setup
The Project Setup table summarizes the structure of the data that has been used as input for the alignment.
| Field name | Description |
|---|---|
Capture Session/Camera Session | Name of the capture session or camera session. |
Camera Name | Name of the camera used for collecting the data of a camera session. |
Image Count | Total number of images for a camera session or capture session. |
Cameras
The Cameras table provides an overview of all the camera sensors used within the alignment. Additionally the camera's parameters are shown if they were enabled for optimization during the alignment.
| Field name | Description |
|---|---|
Camera | Name of the camera. |
Width | Width of the camera's sensor. |
Height | Height of the camera's sensor. |
Pixel Size | Physical size of a single pixel. |
f | Focal length of the camera. |
PPA | Coordinates for the principal point of autocollimation |
Distortion Model | Model used to describe the sensor's distortion. |
Optimization | List of parameters that were activated for optimization during the alignment. |
Adjustment Settings
The Adjustment Settings table documents the values set as input for the alignment.
| Field name | Description |
|---|---|
Camera Sessions | Input values for the position and rotation standard deviations for the camera sessions. |
Control Points | Input values for the XY and Z standard deviations for the control points. |
Control Points
The Control Points table reflects the list of points used as input for the alignment.
| Field name | Description |
|---|---|
ID | Identifier of a point as specified in the input file. |
Role | Role of a point (either ground control point or check point) as defined by the user. |
X | X component of the point's position. |
Y | Y component of the point's position. |
Z | Z component of the point's position. |
Alignment Results
The Alignment Results section contains information on the results of running the alignment. The following tables are in this section:
- Global Shifts
- Lever-Arms
- Boresight Misalignments
- Ground Control Points
- Check Points
- Camera Optimization
- Tie Points
- Image Connectivity
- Reprojection Errors
- Image Residuals
Global Shifts
The global shift is a common translation applied to all camera poses of a capture session to match the datum defined by the set of ground control points.
Note:
Global shifts are only calculated if ground control points are used in the alignment.
| Field name | Description |
|---|---|
Capture session | Name of the capture session. |
X | X component of the translation for a capture session. |
Y | Y component of the translation for a capture session. |
Z | Z component of the translation for a capture session. |
Lever-Arms
The lever-arm 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.
Note:
Lever-arm misalignments are calculated and shown for each capture session.
Note:
The Lever-Arm Misalignment table only appears on your report if you checked the Optimize Lever-Arm Misalignment check box on the Alignment settings pane.
| Field name | Description |
|---|---|
Capture session | Name of the capture session. |
X | X component of the lever-arm for a camera session. |
Y | Y component of the lever-arm for a camera session. |
Z | Z component of the lever-arm for a camera session. |
Boresight Misalignments
The boresight misalignment is the rotational offset between the IMU device and the camera system (single or multi head).
Note:
Boresight misalignments are calculated and shown for each capture session.
| Field name | Description |
|---|---|
Capture session | Name of the capture session. |
Omega | Omega component of the rotation for a capture session. |
Phi | Phi component of the rotation for a capture session. |
Kappa | Kappa component of the rotation for a capture session. |
Ground Control Points
The Ground Control Points table shows the residuals and observation statistics evaluated both globally and individually per point. Global measurements include mean, maximum, and root mean square (RMS) statistics. A 3D residual of a ground control point is the difference between its calculated 3D coordinate in the alignment and the original 3D coordinate. The ground control points residual units are expressed in object space.
| Field name | Description |
|---|---|
Point ID | Identifier of a point as specified in the input file. |
ΔX | X component of the 3D residual. |
ΔY | Y component of the 3D residual. |
ΔZ | Z component of the 3D residual. |
ΔXYZ | Magnitude of the 3D residual. |
Meas. | Total number of image measurements. |
Cameras | Number of camera sessions a point was measured in. |
Check Points
The Check Points table shows the residuals and observation statistics evaluated both globally and individually per point. Global measurements include mean, maximum, and root mean square (RMS) statistics. A 3D residual of a check point is the difference between its calculated 3D coordinate in the alignment and the original 3D coordinate. The check points residual units are expressed in object space.
| Field name | Description |
|---|---|
Point ID | Identifier of a point as specified in the input file. |
ΔX | X component of the 3D residual. |
ΔY | Y component of the 3D residual. |
ΔZ | Z component of the 3D residual. |
ΔXYZ | Magnitude of the 3D residual. |
Meas. | Total number of image measurements. |
Cameras | Number of camera sessions a point was measured in. |
Camera Optimization
The tables within this section show the input values and estimated values, as well as the difference for each camera optimized in the alignment.
| Field name | Description |
|---|---|
Input | Input value for the specified parameter. |
Estimated | Estimated value for the specified parameter. |
Difference | Difference between the input value and the estimated value. |
Tie Points
The Tie Points section provides the number of automatic and manual tie points, along with their image observation statistics.
| Field Name | Description |
|---|---|
Image measurements per point | Provides statistics about the number of images a tie point has been measured in. |
Linked cameras per point | Provides statistics about the number of camera sessions a tie point has been measured in. |
Image Connectivity
The Image Connectivity section shows the number of images and statistics describing their connectivity.
| Field Name | Description |
|---|---|
Automatic Tie Points per Image | Statistics with regard to the number of automatic tie point measurements in individual images. |
Linked Cameras per image | Refers to the number of camera sessions an image is connected with through automatic tie points that can be observed in images of respective camera sessions. |
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 triangulated 3D point onto an image and the original image measurement.
| 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. |
Automatic Tie Points | The residuals of the image measurements used to measure automatic tie points in the alignment. |
Manual Tie Points | The residuals of the image measurements used to measure manual tie points in the alignment. |
Image Residuals
The Image Residuals table lists various error statistics of the exterior orientations parameters (X, Y, Z, omega, phi, kappa) used in the alignment. The image residual is the difference between its calculated orientation in the alignment and the original orientation. The image residuals are expressed in object space and divided into position residuals and rotation residuals. Position residuals refer to the remaining difference in 3D coordinates (X, Y, Z) after applying the estimated Global Shift and Lever-Arm correction (if estimated). Rotation residuals refer to the remaining difference in rotation angles (omega, phi, kappa) after applying the estimated Boresight Misalignment correction.
| Field name | Description |
|---|---|
Position Residuals | The residuals of the image positions used in the alignment. |
Rotation Residuals | The residuals of the image rotations used in the alignment. |