Accession Number : AD0639374

Title :   NUMBER OF PIP-SCANS AND TARGET-DETECTABILITY ON CERTAIN HIGH PERSISTENCE PPI TUBES.

Descriptive Note : Memorandum rept.

Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD PSYCHOLOGICAL LAB

Personal Author(s) : Williams,S. B. ; Hanes,R. M.

Report Date : 10 JAN 1947

Pagination or Media Count : 7

Abstract : Several experiments are currently in progress concerning factors affecting the detectability of targets appearing on cathode-ray tubes used in radar. Because the tubes being used have phosphors (P7) of relatively long persistence, it would be interesting to know whether there is any accumulative effect of repeated excitations on the brightness of a phosphor when the time between excitations is on the order of the interval between successive scans. Such a build-up effect, if it were large enough, would tend to increase the intensity of a stationary pip and render it more visible. An experimental investigation of this question is reported in this paper. Briefly the results of the experiment indicate a small but significant enhancement of phosphor brightness with repeated excitations. (Author)

Descriptors :   (*PLAN POSITION INDICATORS, RADAR SCANNING), (*RADAR IMAGES, BRIGHTNESS), VISIBILITY, DETECTION, CATHODE RAY TUBE SCREENS

Subject Categories : Electrooptical and Optoelectronic Devices
      Active & Passive Radar Detection & Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE