Create an alignment report
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 provide a name for the report.
Click Save.
The alignment report is created as a .pdf file in the specified location. The alignment report is divided into three sections: Summary, Input Data, and Alignment Results. The sections include several tables and maps, which are described below.
Summary section
The Summary section includes general information about the 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 well-known ID (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. Click a Jump to Section link to go to the section of the alignment report that provides additional information related to the metric shown.
Input Data section
The Input Data section includes information about the data used to create the 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 and contains the following fields:
|
Field name |
Description |
|---|---|
|
Capture Session/Camera Session |
The name of the capture session or camera session. |
|
Camera Name |
The name of the camera used for collecting the data of a camera session. |
|
Image Count |
The total number of images for a camera session or capture session. |
Cameras
The Cameras table provides an overview of all the camera sensors used in the alignment. Additionally the camera's parameters are shown if they were enabled for optimization during the alignment. The Cameras table contains the following fields:
|
Field name |
Description |
|---|---|
|
Camera |
The name of the camera. |
|
Width |
The width of the camera's sensor. |
|
Height |
The height of the camera's sensor. |
|
Pixel Size |
The physical size of a single pixel. |
|
f |
The focal length of the camera. |
|
PPA |
The coordinates for the principal point of autocollimation. |
|
Distortion Model |
The model used to describe the sensor's distortion. |
|
Optimization |
A list of parameters that were activated for optimization during the alignment. |
Alignment Settings
The Alignment Settings table documents the values set as input for the alignment and contains the following fields:
|
Field name |
Description |
|---|---|
|
Camera Sessions |
The input values for the position and rotation standard deviations for the camera sessions. |
|
Control Points |
The 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 and contains the following fields:
|
Field name |
Description |
|---|---|
|
ID |
The ID of a point as specified in the input file. |
|
Role |
The role of a point (either ground control point or check point) as defined by the user. |
|
X |
The X-component of the point's position. |
|
Y |
The Y-component of the point's position. |
|
Z |
The Z-component of the point's position. |
Alignment Results section
The Alignment Results section contains information about the results of running the alignment. The following tables are in this section:
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. The Global Shifts table contains the following fields:
Note:
Global shifts are only calculated if ground control points are used in the alignment.
|
Field name |
Description |
|---|---|
|
Capture session |
The name of the capture session. |
|
X |
The X-component of the translation for a capture session. |
|
Y |
The Y-component of the translation for a capture session. |
|
Z |
The 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. The Lever Arms table contains the following fields:
Note:
Lever arm misalignments are calculated and shown for each capture session.
Note:
The Lever Arm Misalignments table only appears on the report if you checked the Optimize Lever-Arm Misalignment check box in the Alignment settings pane.
|
Field name |
Description |
|---|---|
|
Capture session |
The name of the capture session. |
|
X |
The X-component of the lever arm for a camera session. |
|
Y |
The Y-component of the lever arm for a camera session. |
|
Z |
The Z-component of the lever arm for a camera session. |
Boresight Misalignments
A boresight misalignment is the rotational offset between the inertial measurement unit (IMU) device and the camera system (single or multihead). The Boresight Misalignments table contains the following fields:
Note:
Boresight misalignments are calculated and shown for each capture session.
|
Field name |
Description |
|---|---|
|
Capture session |
The name of the capture session. |
|
Omega |
The omega component of the rotation for a capture session. |
|
Phi |
The phi component of the rotation for a capture session. |
|
Kappa |
The 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. The Ground Control Points table contains the following fields:
|
Field name |
Description |
|---|---|
|
Point ID |
The ID of a point as specified in the input file. |
|
ΔX |
The X-component of the 3D residual. |
|
ΔY |
The Y-component of the 3D residual. |
|
ΔZ |
The Z-component of the 3D residual. |
|
ΔXY |
The magnitude of the planimetric residual. |
|
ΔXYZ |
The magnitude of the 3D residual. |
|
Meas. |
The total number of image measurements. |
|
Cameras |
The number of camera sessions a point was measured in. |
The ground control points maps display the spatial distribution of the 3D XYZ residuals, planimetric XY residuals, and residuals for each ground control point in the alignment. In the XY residuals map, the arrows indicate the direction of the residuals and are colored and scaled according to the residual magnitude.
The Estimated Ground Control Points table shows the 3D coordinates of each ground control point as estimated by the alignment. The ground control points coordinates units are expressed in object space. The Estimated Ground Control Points table contains the following fields:
|
Field name |
Description |
|---|---|
|
Point ID |
The ID of a point as specified in the input file. |
|
X |
The X-component of the estimated position. |
|
Y |
The Y-component of the estimated position. |
|
Z |
The Z-component of the estimated position. |
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 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. The Check Points table contains the following fields:
|
Field name |
Description |
|---|---|
|
Point ID |
The ID of a point as specified in the input file. |
|
ΔX |
The X-component of the 3D residual. |
|
ΔY |
The Y-component of the 3D residual. |
|
ΔZ |
The Z-component of the 3D residual. |
|
ΔXY |
The magnitude of the planimetric residual. |
|
ΔXYZ |
The magnitude of the 3D residual. |
|
Meas. |
The total number of image measurements. |
|
Cameras |
The number of camera sessions a point was measured in. |
The check points maps display the spatial distribution of the 3D XYZ residuals, planimetric XY residuals, and Z residuals for each check point in the alignment. In the XY residuals map, the arrows indicate the direction of the residuals and are colored and scaled according to the residual magnitude.
The Estimated Check Points table shows the 3D coordinates of each check point as estimated by the alignment. The check points coordinates units are expressed in object space. The Estimated Check Points table contains the following fields:
|
Field name |
Description |
|---|---|
|
Point ID |
The ID of a point as specified in the input file. |
|
X |
The X-component of the estimated position. |
|
Y |
The Y-component of the estimated position. |
|
Z |
The Z-component of the estimated position. |
Camera Optimization
The Camera Optimization tables show the input values and estimated values, as well as the difference for each camera optimized in the alignment. The Camera Optimization tables contain the following fields:
|
Field name |
Description |
|---|---|
|
Input |
The input value for the specified parameter. |
|
Estimated |
The estimated value for the specified parameter. |
|
Difference |
The difference between the input value and the estimated value. |
Tie Points
The Tie Points table provides the number of automatic and manual tie points, along with their image observation statistics. Additionally, the tie points maps display the spatial distribution of the automatic tie points colored according to the number of image measurements and the number of unique cameras. The Tie Points table contains the following fields:
|
Field Name |
Description |
|---|---|
|
Image measurements per point |
The number of images a tie point has been measured in and the related statistics. |
|
Linked cameras per point |
The number of camera sessions a tie point has been measured in and the related statistics. |
Image Connectivity
The Image Connectivity table shows the number of images and the statistics describing their connectivity and contains the following fields:
|
Field Name |
Description |
|---|---|
|
Automatic Tie Points per Image |
The number of automatic tie point measurements in individual images and the related statistics. |
|
Linked Cameras per image |
The number of camera sessions an image is connected to through automatic tie points that can be observed in images of respective camera sessions and the related statistics. |
Reprojection Errors
The Reprojection Errors table lists various reprojection error statistics for points used in the alignment and contains the fields described below. The reprojection errors are reported as separate components along x and y, and as the magnitude of the combined x,y residual.
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 |
|---|---|
|
Alignment Points |
The residuals of all points influencing the alignment result (i.e., ground control points, automatic tie points and manual tie points). |
|
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. |
The tie points map displays the spatial distribution of the automatic tie points colored according to the RMS of reprojection errors
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. |