Experts who study unmanned aircraft systems, better known as drones, say it can be tough to tell from miles away. But there are clues. A light in the sky at night can easily be misinterpreted ...

NEW JERSEY - Is it a drone, a plane or a helicopter in the sky? Experts who study unmanned aircraft systems, better known as drones, say it can be tough to tell from miles away. But there are clues.

Up in the sky, is that a drone, a plane or a helicopter? Experts who study unmanned aircraft systems — better known as drones — say it can be tough to tell from miles away. But there are clues.

Up in the sky, is that a drone, a plane or a helicopter? Experts who study unmanned aircraft systems — better known as drones — say it can be tough to tell from miles away. But there are clues.

Experts who study unmanned aircraft systems — better known as drones — say it can be tough to tell from miles away. But there are clues. A light in the sky at night can easily be ...