In these days, I see small aircraft like P68 fly with a very accurate "grid-like" pattern. I'm sorry but I don't know the correct word. Here a couple of examples, grabbed today at the same time:
and
What kind of job they might do with these routes? I don't think it's about agriculture because the patterns are too long and they fly over cities and sea as well (and I don't think this kind of aircraft is the most suitable for such a task).
I thought about observation of restriction for COVID-19, but I would use helicopters instead of aircraft, and again the patterns are so long for just be sure if anyone goes out for a walk.
Any sort of collecting photographic data? Like Google does for its Maps?