Accession Number : AD0640075

Title :   SIMULATED DISPLAY OF BEARING AND RANGE IN RECTANGULAR COORDINATES.

Descriptive Note : Technical rept.,

Corporate Author : JOHNS HOPKINS UNIV BALTIMORE MD PSYCHOLOGICAL LAB

Personal Author(s) : Gebhard,J. W. ; Barber,J. L. ; Halsey,R. M.

Report Date : 01 MAY 1949

Pagination or Media Count : 14

Abstract : Several experiments were conducted to determine the speed and accuracy with which target position can be read from an experimental display of radar bearing and range information in rectangular coordinates in which 360 degrees of bearing were given on the x-axis and 40,000 yards of range were shown on the y-axis. A rectangular scope, produced by modifying a VD radar indicator, was first compared with a PPI with respect to accuracy of aligning a movable range marker with blips. The rectangular display was found to produce smaller alignment errors than the PPI, and to be free from the effect, present in PPIs, of greater error with longer ranges. The factor of target length had no effect on accuracy for the experimental display whereas on the PPI arc length interacts strongly with target range in determining alignment error. Several bearing grids were tested on a simulated rectangular display for the purpose of selecting the most suitable design. Bearing scales marked in intervals of 20 degrees were found superior to those marked in intervals of 30 degrees as measured by speed of reading and bearing error when visual estimations of target position were made. Size of display had no effect on either speed or accuracy, nor did different starting points of the bearing scale. It is concluded that a rectangular display is as efficient as, and in some respects superior to, a PPI for estimating target position. Its adaptability for displaying information for tactical evaluation is questionable due to the presence of distortion. (Author)

Descriptors :   (*RADAR TARGET POSITION SIMULATORS, *DISPLAY SYSTEMS), DIRECTION FINDING, RANGE FINDING, PLAN POSITION INDICATORS, HUMAN FACTORS ENGINEERING

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

Distribution Statement : APPROVED FOR PUBLIC RELEASE