The WESCAM System is a gyrostabilized aerial filming platform. It appears like a swivelling "ball" attached to the helicopter with a "window" through which the camera can film. The television and production companies, movie industry, police and military forces are the main users for this kind of equipment.

Why a gyrostabilized platform ?

Everyone who already has operated a camcorder knows that when you zoom in a subject, the image become unstable due to the operator's arm and hand instability and shaking. Imagine now a helicopter that can be considered as a good vibration generator and from which you have to zoom in the number of a Tour de France racing cyclist or the license plate of a moving vehicle on a highway. Such requirements are impossible to meet without a stabilization device for the camera. Several camera stabilization systems have been designed in order to be installed on helicopters.

A first category could list all camera mounts such as those produced by Tyler for instance. A major disadvantage of those systems is certainly that the camera itself is exposed to the elements as beeing installed outside the helicopter or on a side mount for the best. In the case of this last installation option, the azimuth range is often very limited. But, outside installed systems can nevertheless work as multi-camera in order to shoot 180° or even 360° panoramic movies.

The second category is made of all gyrostabilized "ball" systems. Canadian Wescam company has forged its name as a specialist in this kind of systems, but it is not alone.

How does a gyrostabilized platform work ?

As its name let it think, a gyrostabilized platform is based on a gyroscopic system. A gyroscope has the property to hold its revolution plane once turning at high speed no matter of the external perturbations whether the revolution plane can freely move around the two other axles. There are two stabilization systems :

The first-one is a support on which the whole camera and gyroscopic system is suspended by means of a flexible link. If the support, which is mechanically and directly connected to the helicopter, vibrates, the camera-gyroscopes assembly remains stable due to the gyroscopes' physical properties.

The second-one is based on an active correction of the vibrations in phase opposition. The gyroscopic system allows to evaluate amplitude and frequency of vibrations and that information is computed in real time by the electronic of the system that act on the active suspension device.