Accession Number : AD0639367

Title :   SIGNAL MARK SIZE AND VISIBILITY OF RADAR SIGNALS ON A PLAN POSITION INDICATOR.

Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD PSYCHOLOGICAL LAB

Personal Author(s) : Bartlett,N. R. ; Williams,S. B.

Report Date : 20 SEP 1947

Pagination or Media Count : 20

Abstract : Preliminary research on the detectability of signal images on a 7BP7 radar screen indicates the extreme importance of the image size. Image size was varied (1) by regarding the radar screen from different distances, (2) by changing the length of the image by widening the azimuth gate, (3) by changing the thickness of the image by switching to different presentation range scales and (4) by moving the signal from the center to the periphery of the screen. Image size variations by such methods can change the strength of the minimum visible signal by at least eight or ten decibels. The data are preliminary, for equipment limitations did not permit variations from a signal pulse length of two microseconds nor reductions in azimuth gate below 12 degrees. Further research on the problem of image size with refined equipment is now in progress. (Author)

Descriptors :   (*PLAN POSITION INDICATORS, RADAR SIGNALS), (*RADAR IMAGES, VISIBILITY), MAN MACHINE SYSTEMS, VISUAL PERCEPTION

Subject Categories : Electrical and Electronic Equipment
      Active & Passive Radar Detection & Equipment
      Human Factors Engineering & Man Machine System

Distribution Statement : APPROVED FOR PUBLIC RELEASE