Title

Masking Of Cathode Ray Tube Display By Ambient Illumination

Date

1953

Index Abstract

Not Available

Photo Quality

Not Needed

Report Number

WADC TR 53-266

Creator

Adler, Helmut E.

Brown, John L.

Kuhns, Margaret P.

Corporate Author

Columbia University

Laboratory

Aero Medical Laboratory

Extent

25

PB Number

PB133972

NTRL Accession Number

AD030677

Identifier

AD0030677

Access Rights

Unknown

Distribution Classification

1

DTIC Record Exists

Yes

Distribution Change Authority Correspondence

Air Force Aerospace Medical Research Lab ltr

Distribution Conflict

Fix

Abstract

Masking thresholds of ambient illumination were obtained for a signal presented as a horizontal trace on a cathode ray tube. Seven trace luminances and two trace widths were used. Ambient illumination was measured in terms of the luminance superimposed on the surface of the tube. The results show that in radar operation ambient light can be present considerably in excess of the signal strength without masking the signal display, except when the signal luminance is below 0.1 ml. If the signal strength is increased by a small amount, the masking threshold for anibient light rises rapidly at first, but at a decreasing rate, and eventually reaches a point where further increases in trace luminance do not result in a further increase in inasking threshold. Above this level of ambient light (somewhat higher than 1000 ml in this experiment) no increase in signal strength can compensate for the masking effects of the ambient light. Increasing the dimensions of the trace, while holding trace luminance constant, appears to afford tolerance for somewhat more ambient light.

Report Availability

Full text available

Date Issued

1953-11

Provenance

Hunt Library, Embry-Riddle Aeronautical University

Type

report

Format

1 online resource