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Projected Map Display back end projector housing

Technical Information

Catalogue No: PM32495
Picture Type: Rochester Photo Negative
Topic: Navigation/Inertial
Title: Projected Map Display back end projector housing
Platform(s): Jaguar 
Date: 6 Apr 1977
Width (mm): 127
Height (mm): 102
Copies: 1
Location: Negatives Cabinet PM ("54/") [RAA Office]
Notes:

Reference to C0193 shows the split of the Light Source and power block from the film and projection unit.

This Projected Map system predates the modern digital systems and uses 35mm film as the data store. The film is stored on spools mounted in a moveable carriage. A tungsten halogen lamp provides the light source to project the map image via an optical system on to a ground glass screen. A fresnel lens covering the screen gives even illumination and intensifies the image in the pilot’s field of view. The film strip is driven between the two spools at a rate proportional to the Easterly ground speed while the carriage holding the spools is driven in a perpendicular direction proportional to the Northerly ground speed. The map can be presented as North or Track oriented. The screen can be rotated and has a track arrow. The aircraft’s present position, track and track to the next waypoint can be presented. A film can cover an area of about 750 by 750 nautical miles with a Scale change for 1:250 000 or 1: 500 000. The PMD was used in the Jaguar Navigation and Weapon Aiming Sub-System NAVWASS. The Marconi Avionics system was replaced with TIALD from 1995

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