Don't know what I did there but it doesn't seem to want to delete.
I'm with you windsock but that is old style policing - we must have the high tech solution now.
Again, if it is a man in a white van, he would be targetting another airfield now.
I reckon the perpetrator is within a very few miles of whichever end of Gatwick these sightings are occurring.
Funny that in these days of instant messaging etc. no one has posted a photo.