Adjust camera parameters

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Adjust camera parameters

Adjust camera parameters

The workflow of improving the camera calibration values is very close to the calibration workflow described in Airborne camera calibration.

1. Collect a few Ground tie points in several images manually or half-automatically.

2. Solve and apply misalignment angles using Output report command in the Tie points window.

3. Collect more tie points and filter out bad tie points.

If the mismatch distances for tie points become smaller (about 2-3 * pixel size of the raw images), try to switch to half-automatic tie point entry mode. See Tie point entry modes.

4. Solve and apply misalignment angles using Output report command in the Tie points window.

5. Solve principal point z using Tools / Solve parameters command in the TerraPhoto camera dialog.

6. Recompute the tie points by using the Apply button in the Camera dialog.

7. Go back to step 3 until images are well-defined regarding Tie point values and Tie point distribution. Continue until the values for the misalignment angles and principle point z do not change significantly anymore.

8. Solve all other solvable parameters using Tools / Solve parameters command in the Camera dialog and apply the changes to the tie points.

The application adjusts roll and pitch misalignment angles if it modifies principal point x and y values. The adjustment of the misalignment angles compensates the modification of the other parameters.

You may still check for bad tie points using the Find worst command from the Tie points window.

9. Go back to step 8 and continue until there is no more improvement and the values are stable. The mismatch of the tie points should be around 1 * pixel size of the raw images or smaller.