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Introdution

Geo-tagged aerial pictures are very useful for mosaic mapping as well as the creation of accurate 3D models from a terrain.

Michael Oborne added a great tool for injecting GPS data on the EXIF tags by using APM's telemetry log from a flight.
This tutorial was created to show you how does it work.
This is a work from Sandro Benigno and Guto Santaella who kindly provided the sample files and screenshots used for making this tutorial.

Step by Step

1: Open the Mission Planner and press "Ctrl+F". It will open a hidden screen, like shown here:



2: Click the button "Geo ref images".
It will give you access to the Geo Tagging resource as shown below:



3: Click the button "Browse Log" and select the telemetry log (.tlog) of the flight related to the shooting session.
Note: You can use both sources: the "Logs" folder from Mission Planner install or you can download it from the APM's dataflash through the USB port.
4: Click the button "Browse Directory" and select the folder where your aerial pictures was downloaded from your camera.



5: Just to illustrate, the screen below shows the mission used for creating this tutorial:



6: The next step is clicking on "Estimate Offset". It will try to extract the offset from the "Log Start Time" and the "Shooting Time" from the first picture taken.
The result shows "offset should be about...". You need to take the guessing and insert it manually on the field "Seconds offset".



7: Click the button "Do it" and wait until the processing is finished. The number shown in "Done... matches" must be the number of pictures taken. Otherwise it means that the sync isn't good enough.
8: After the previous step you can verify the positioning of each picture on Google Earth by clicking "Location Kml".



9: Looking at the example above you'll see the estimated position of a picture. You can click any images at the list on left to check it. If the position is not accurate you can step back and retry it from the step "6" by increasing or decrasing the "Seconds offset" a little bit, just like a fine tuning.
10: After finishing the tuning, all you need to do is click "Geo Tag Images". This process will add geographic data to your picture, i.e. Latitude, Longitude and Altitude.
The processing creates new files with a suffix "_geotag". The original set of pictures remains untouched.



11: You can check your pictures by visualizing the file properties details. You should see the inserted GPS tags on the EXIF data.


Thanks to Michael Oborne by one more awesome tool! ;)