Crackling air device

This crackling air device was disturbing our peaceful day ;-) I was wondering why helicopter is flying back and forth and around above our village.
I suppose, it is again that time of the Decade when they are taking aerial photos from our homes. Anf then they come to ring our doorbells and try to sell us those photos. Of course in picture of our house is clearly seen someone taking photos in the backyard pointing the lens towards the helicopter ... ouh yeah ... great ;-D