"In the article they were saying that they used to do it with a helicopter after the airport closed at night but it was rather expensive and quite noisy (GVA is really close to the city and both the approaches pass above geneva's suburbs )"

"i guess it flies to know altitudes so as to match the glide-slopes for the PAPI system at a known point and then the video is checked to make sure the right color is seen. for the runway light its is just a mater of visually comparing what is on the…"

"Geneva's airport (GVA) has acquired what looks to be a modified DJI F550 to survey there runway lights and PAPI system for a little more than 12k€. Original article in french
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