The helicopter flying over fields, rivers and villages in central Poland is loaded with high-tech cameras and sensors. The pilot, an army veteran who served in Iraq and Afghanistan, keeps the small Robinson R66 low to the ground.

The chopper is on a surveillance mission and its route follows miles of high-voltage lines connected to a key power plant south of Warsaw. The equipment on board, designed to monitor for tampering, is incredibly precise. It can even detect if someone has disturbed the ground or whether a vehicle has passed under the line.