Good job! OSINT rules.
And regarding drones, surely any state actor may be doing this, however doing surveillance by drones over military bases is just so noob. That just points out they don't have a capacity to do reconnaissance with satellites, or they are doing something completely different. Probably making sure the target knows someone is watching, saying "We know where you have your sensitive spots".
They don't need satellites, they can surveil us close up with £200 drones and we don't do anything about it. It's like the story about the astronaut and the pencil.
