Present criteria for aeronautical charts need further investigation in preparation for S.S.T. operations in respect to the facilities to be charted, the format for supplemental information, symbols and scale. For projection displays the negative presentation has decided advantages, while the use of colour has both advantages and disadvantages. Pre-loaded film cassettes for quick insertion into the dynamic display system can be maintained in libraries at S.S.T. terminals, which will also facilitate the frequent updating of the material.

In recent years the interest in dynamic map display systems has increased with the advent of S.S.T. planning and higher speed tactical aircraft. There are several approaches including a static chart with a mechanically driven ‘bug’, a moving paper chart with a static ‘bug’ in the form of a stylus, and several projected displays utilizing 35 mm. and 70 mm. film. This paper is chiefly concerned with projected displays.