Create and edit an alignment

You can improve the accuracy of the georeferenced position and orientation of your camera sessions by creating an alignment. With an alignment, you can also refine the internal camera definition parameters.

Create an alignment

To create an alignment, complete the following steps:

1. On the Home tab, click New Alignment .
2. Type a name for the alignment in the Alignment Name text box.
3. In the Camera Sessions section, check the camera sessions you want to include in the alignment.

   You must select at least one session. Camera sessions included in the alignment must contain images.

   Note:

   For multiple camera sessions, all camera sessions must have the same spatial reference.

   Tip:

   In the Camera Sessions section, previously aligned camera sessions are located in their respective alignment. When you check a capture session, all the camera sessions in it are automatically checked.

4. Optionally, you can optimize the camera calibration settings of the camera sessions. The calibration settings are contextual to the selected camera session. In the Camera calibration settings for section, check the camera settings you want optimized by the alignment.
   1. Check Optimize Focal Length to estimate the focal length of the camera.
   2. Check Optimize PPA to estimate the Principal Point of Autocollimation (PPA).
   3. Check Optimize Distortion to model the distortion of the camera based on the Distortion Model stated directly below.

   The optimization is applied only to the selected camera session.

5. Optionally, under Control Points, click Import Control Points to add them to the alignment.

   Tip:

   Learn how to import control points.

6. Optionally, under Control Points, check the check box next to the control points to add them to the alignment.

   Note:

   Only control points with the same spatial reference as the selected camera sessions can be used.

   Tip:

   If the control points have existing manual image measurements, you can check the manual image measurements from the drop-down menu below the control points to include them in the alignment.

7. In the Standard Deviations section, for Camera Sessions, type the standard deviations of the position and rotation for the camera sessions.
8. In the Standard Deviations section, for Control Points, type the standard deviations for the control points.
9. Optionally, select a Region of Interest from the drop-down menu.
10. Click Create.

    Tip:

    Click the Create drop-down arrow and click Create and Run to create and start the processing of the alignment simultaneously.

The alignment is created and appears in the project tree. An alignment directory is created in the project directory to store the alignment settings and data.

Edit the alignment settings

To edit the alignment settings, complete the following steps:

1. Select the alignment in the Project Tree.
2. On the Alignment tab, click Settings .
3. Edit the alignment settings as necessary.
4. Click Save.

   Note:

   • Changing some of the settings resets the alignment and deletes some results.
   • A warning dialog box appears, to confirm whether you want to continue before saving the changes.

The alignment is updated.