Stewart Penney/CRANFIELD
AUK Defence Evaluation and Research Agency (DERA) and Cranfield Aerospace team is planning a series of trials of the Observer unmanned air vehicle (UAV) equipped with an uncooled thermal imaging sensor. The UAV will also be demonstrated to a USAir Force agency late March.
Observer is a short range UAV using a gust insensitive delta-wing platform. Dave Dyer, Cranfield Aerospace business manager, control systems, says the neutrally stable airframe was chosen as it allows the sensor suite to be simplified. With a conventional UAV, the sensor has to be gimballed to track a ground target as the platform rolls, yaws and pitches when rocked by air gusts during flight. Instead, the Observer simply translates to another height or track, which allows a fixed sensor suite.
The next stage of flight trials, due to start this month, will replace the daylight television sensor with a thermal imaging system developed by DERA Malvern.
Unlike conventional systems, the compact sensor for Observer has no cooling engine to reduce the staring array's temperature so it can "see" the outside world. The unit has a 40í x 30í field of view, which is gimballed in pitch to provide the data for Observer's image-based navigation system.
DERA programme leader David Potts says that the "unique" image- based navigation system will be developed for section-level UAVs smaller than Observer, allowing many cheaper and smaller vehicles to be used by frontline troops.
Dyer says the navigation system is geometry based, with the Observer's flight control system taking the UAV's position, provided by GPS satellite navigation and the target's location, then calculating the flight path of the platform so that the "point of interest" is within the sensor's field-of-view. Control is provided by the operator indicating positions of interest on a map display or sensor image view, both of which are shown on touch-screen displays.
The control system automates the UAV operation, as it does not require dedicated pilots, which in-turn reduces the manpower and training overheads.
Source: Flight International
