The Effect of CRT Bias on Visibility of Targets on a Remote PPI
Abstract
The cathode ray tube of a VD remote PPI indicator has an optimal bias level with respect to target visibility. Every experiment in which CRT bias was varied yielded a curve of visibility with a maximum lying somewhere between the lowest and highest intensity (CRT bias) settings. In all cases maximum visibility was obtained with a moderately bright, light yellow background, that is, with a comparatively low bias, and not with the dark or high bias background frequently employed by trained operators. The exact specification of this optimal level in volts or in units of illumination is not yet possible with existing measuring instruments. However, it can be fairly well defined visually.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 10, 1946
- Accession Number
- AD0639371
Entities
People
- Ellwood King
- S. B. Williams
Organizations
- Johns Hopkins University