Sira simulates the views of a fighter pilot

Citation

(1998), "Sira simulates the views of a fighter pilot", Aircraft Engineering and Aerospace Technology, Vol. 70 No. 4. https://doi.org/10.1108/aeat.1998.12770daf.005

Sira simulates the views of a fighter pilot

Sira simulates the views of a fighter pilot

Keywords Aircraft, Optics, Sira

Sira Electro-optics Division is developing a module that can emulate the keen eye of a fighter pilot in the latest piece of equipment it is building for the Defence Evaluation Research Agency (DERA).

Sira claims its "artificial eye" will be able to go one better than even the best-trained pilot. It will not only see what the pilot is seeing through his helmet-mounted display, it will also provide an objective evaluation of the quality of the image the pilot is viewing (Plate 4).

Helmet-mounted displays are increasingly being used by pilots of military aircraft. They present before the eyes of the pilot conventional instrument data which traditionally would have been displayed on a control panel or "head-up" display; and they can also 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. Currently, the performance specifications of individual head-up displays vary enormously.

Plate 4 Sira Electro-optics Division is developing a module that can provide an objective evaluation of the quality of the image a pilot is viewing through his helmet-mounted display. (Photograph courtesy of GEC-Marconi Avionics)

Without objective data, it is impossible to know precisely what the pilot will see or was seeing.

Sira's problem was 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/her eyes as well as any misalignment between the pilot's eyes and the helmet-mounted display.

The company's solution was to design a compact image analyser that could not only be operated inside a helmet but could also be moved around to simulate all the pilot's possible fields of view.

This meant creating an artificial electronic version of a real eye. Sira's 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 ­ of the virtual image of the test pattern generated by the test piece ­ 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.

The image analysis module is just one of several that make up the complete test facility which has been designed to test both complete helmet-mounted systems and individual system components.

Its modular format allows the facility to be used in a number of different configurations for carrying out tests of various complexities from measuring astigmatism in lenses to evaluating image intensifiers and video display units.

Details from Sira Electro-Optics Ltd. Tel: +44 (0) 181 467 2636.