Minimum effort project strategy

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Minimum effort project strategy

Minimum effort project strategy

This workflow outline is based on the following conditions:

Reasonable positional accuracy is enough for the orthophotos.

Image timing and raw positioning is accurate.

The camera system is stable and the internal geometry of the camera is known beforehand.

Final orthophoto does not have to be high quality - it is acceptable to have some detectable seamlines.

These circumstances make it possible to choose a quite automatized workflow with very little operator time spent on the job. The project workflow may proceed with the following steps:

1. Create a TerraPhoto camera calibration file using values from a previous calibration.

2. Define a mission with New mission command.

3. Import trajectories using Manage Camera Trajectories tool.

4. Create an image list with Compute list command.

OR

3. Define an exterior orientation file format in Exterior orientation formats of TerraPhoto Settings.

4. Create an image list by importing exterior orientation files with Load list command.

If you use data from a Pictometry system, the camera calibration files, the mission file, and the image list can be created automatically by importing the Pictometry survey file. See Import Pictometry Survey command.

5. Create thumbnail versions of raw images with Create thumbnails command.

6. Enter tie points with Define tie points command in a few (5-10) images. You should choose images from a couple of different locations. Choose places which have clearly identifiable objects on the ground (such as paint markings on asphalt) and have a good overlap pattern (crossing flight lines if possible).

7. Create an Output report to make sure that the starting mismatch of the tie points is at an acceptable positional level and that the camera misalignment angles match the camera parameters.

If the camera misalignment is not valid, apply new values given in the report. Make sure that the tie point mismatch is small after applying the new misalignment angles.

8. Search for automatic color points with Search points command from the Color points menu for balancing color differences between neighboring images.

9. Create tile rectangles with Place tile array command.

10. Run orthorectification with Rectify mosaic command using the image list based on raw positioning and color points.