How can I generate a PhotoId file?

CloudStation Colorization module and TerraPhoto module from TerraSolid need a file that will create a link between the photo's name and the event corresponding.

To create a timestamp file (PhotoId file), go to "Project Settings", in the "Camera" tab, "Lever arms, Boresight and PhotoID" sub-menu. Select "Edit/Create PhotoId File".

PhotoId_file_1

 

The 1st column presents the list of events. Check the total number of events recorded, and the time difference between two events. If the time interval is set to 2 seconds (as in this example), then the time delta shouldn't vary more than 0.2sec around this value. A time delta of 0.15sec, for instance, would be the sign an electronic rebound, generating a fake signal. You can exclude the bad event by ticking on the box next to it.

 

The 2nd column shows the list of pictures attached to this flight. Click on "Browse for Folder" and select the directory where the photos are stored (one folder per flight and per camera). The number of pictures and the number of events must be equal. Please check that the photos' name are sorted in a logical way. If that is not the case, try to import the photos by using "Browse for Images" and selecting all the photos needed instead of the folder.

 

The 3rd column makes the link between the events and the pictures' name. This column is automatically populated once the number of active events and the number of pictures in the 2nd column is identical.

PhotoId_file_2

If the 3rd column is not populated : check the total number of events, and the total number of images. If there are too many events, look for fake event (time delta far too small). If the total number of images is too big, that means some pictures were taken outside of the time range of the LiDAR acquisition (either before or after the LiDAR logging). Exclude the images that are not supposed to have a matching event. In order to avoid this issue, please refer to our LiDAR system manual on camera handling procedure.

 

Finally, click on "Export PhotoId File" to save a text file that contains the pictures timestamps, with a .dat If you press OK, the PhotoId list will be validated (and triangles will change color on the View Plan). If you just close the window, it will not validate the list, but PhotoId file is saved anyway.

 

For CloudStation 2305.1.0 and later, the use of the PhotoId file is expected to respect the folder structure as described in CloudStation user manual. In that regards, the PhotoId file must be named event1_Mission 1.dat and be saved in a folder GNSS PostProcess located at the same place than the raw LiDAR data:

PhotoId_file_3

 

Dual Camera: for dual-camera systems, the procedure needs to be repeated, once for each camera/event. For this reason, photos from each camera must be stored in different folders.

PhotoId_file_4