What the pilot saw

Helmet-mounted displays are increasingly being used by pilots of military aircraft. They present to the pilot conventional instrument data that previously was displayed on a control panel or HUD; and they can display external images, such as those produced by infra-red thermal imagers and image intensifiers.

DERA has a requirement to determine objectively and consistently the performance of these displays before procurement and during active service life. Without objective data, it is impossible to know precisely what the pilot will see or was seeing.

Sira Electro-Optics Division was asked to create a piece of equipment that could not only simulate the pilot’s view but could also measure the effect of the pilot moving his eyes as well as any misalignment between the pilot’s eyes and the helmet-mounted display.

This entailed creating an artificial electronic version of the real eye located where the pilot’s pupil would be that could be operated inside a helmet and move around to simulate all the pilot’s possible fields of view.

The resultant image analyser module has an entrance pupil which can be positioned where the pilot’s pupil would normally be and a CCD camera instead of a retina. The module’s optical system forms a real image in the focal plane of the camera.

An optical and mechanical arrangement allows the device to view an image at any specified position in the image field of the test piece.

Sira Electro-Optics 0181 467 2636