12-2] 



USES OF DISPLAY INFORMATION 



609 



Broadly speaking then, the display system may be represented as a 

 communications link as shown in Fig. 12-2. In designing such a system, 

 it is necessary to answer — in order — three questions: 



1. What are the output requirements? That is, what is the use to 

 which the transmitted message is to be put? 



2. What is the nature of the input information (messages) ? 



3. How should the information be coded and transmitted to provide 

 the most efficient link? 



Fig. 12-2 The Data Processing and Display System Viewed as a Communications 



Link. 



Each of these questions will now be treated in a general fashion to provide 

 the reader with background knowledge. Then, the characteristics and 

 problems of specific types of displays and display devices will be treated. 



The weapons system application determines the use requirements of the 

 display information. The following is a summary of some of the more 

 important functional uses of display information in airborne weapons 

 systems. 



Detection and Identification. In many applications, the human 

 operator serves as the final detection stage of the radar system. (This is 

 particularly true of noncoherent pulse type radar systems.) From a display 

 of the radar infortnation, he is required to detect the presence of targets and 

 to distinguish between bona-fide targets and signal indications caused by 

 noise, ground clutter and other sources of interference. The advantages of 

 such an operation lie in the human operator's superior ability to utilize size 

 and shape of the return signal information in addition to ^/A^ ratio. Also, 

 as pointed out in Paragraph 3-3, the display itself can provide signal 

 integration which enhances the S jN ratio. The principal disadvantage is 

 the necessity for an optimum match between the characteristics of the 

 radar, the display, and the human operator. Although detection and 

 identification is one of the oldest uses of radar information, many facets 

 of this problem remain unknown or unsolved. 



Tactical Situation Assessment and Monitoring. A display 

 system may combine radar and other information to construct a pictorial 

 or symbolic representation of an overall tactical situation. For example, 



