Please switch to 720p HD if not done yet!
I filmed this event with my kids, so I know exactly where I was standing. This helped me to use “Dioptra”. I’ve been using this app since a while but be cautious, it needs to be calibrated to be accurate.
I do think I filmed a drone but it was not flying near the hill and never passed behind it because if it was the case, it would have flown too fast for a drone and my friend Titi who is a drone instructor told me that if the drone passed behind the hill, the pilot would have lost connection even if he was standing on top of the observatory (it’s possible to go there btw).
I trust him since he has been there and done that. 🙂
Here is how I used “Dioptra” to find the azimuth. The drone would have been flying much closer to me between the two LOS displayed in my last image below. What happened is that I lost visual contact with it when from my perspective, it seemed to pass over and behind the hill. If not, it’s a UFO (as Unidentified).
Conclusion: “Dioptra” can be a great tool when you know how to calibrate it and if you know the exact location of the witness/observer.