12-10] 



SPECIAL DISPLAYS 



-Diachroic Mirror 



675 



Windshield 



♦- Line of Vision 



Fig. 12-50 Windshield Projection Using Diach 



lacnroic 



Mi 



the Office of Naval Research and the Bureau of Aeronautics to provide 

 visual signals which are easier to interpret by the operator and thus to 

 improve his decision-making capability. These symbols are intended to 

 give to the operator a presentation similar to his view if he were to look 

 out of his windshield. 



The contact analogue display considers that external references, terrain 

 texture, size, motion, shape, and perspective are the elements needed in the 

 display to most readily present his environment to the operator. The 

 information obtained by the contact analogue method is intended not only 

 to improve the 'strike' presentation but also to provide information for 

 takeoff and land, navigation, and aircraft instrument display. 



As shown in Fig. 12-51 a display of 

 grid structure simulates increasing 

 or decreasing terrain texture as the 

 aircraft gains or loses altitude. The 

 convergence of the grid lines toward 

 the center of the display gives per- 

 spective to the presentation. Dis- 

 tance can easily be imagined. Air- 

 craft speed is shown in such a 

 display by the relative motion of the 

 horizontal grid lines toward the base 



of the display. Variation of motion of the grid lines easily illustrates a 

 variation in aircraft speed relative to the ground. Aircraft roll, as shown in 

 Fig. 12-52, is represented by a rotation of the grid structure in the same 

 direction as the aircraft's attitude. Pitch is displayed by displacing the 

 horizon grid line away from the center of the tube as shown in Fig. 12-52. 

 Yaw, in turn, is displayed by moving the vertical center of the scope picture 



Fig. 12-51 Contact Analogue Display. 



