LINEAR END STROKE SENSOR SERIES LES1000
The LES1000 End Stroke Sensor aims to detect the presence of nearby objects without any physical contact, having a linear motion in distance, or closed to be linear. The principle is based on Eddy current sensor (ECS) technology from CEDRAT TECHNOLOGIES: This sensor generates an AC magnetic field at high frequency and senses the behavior of the induced magnetic field in regards of a conductive target (Aluminum is preferred).
NHS drones cross Firth of Clyde in latest CAELUS trial
Hope they have made sure the drone floats, should there be a system failure while in flight. And a rescue service to pick it up.