Three Tone PPI (Plan Position Indicator)
Abstract
A method to overcome a limitation of a radar picture on the screen of a cathode ray tube is described. The three-tone PPI overcomes this limitation in part by providing two limit levels; one for general land signals, and one for the more prominent targets. This is accomplished by either a time division method or by methods which divide, separately amplify, and later mix the tow classes of signals. The result is a composite picture which shows general land signals and built up areas contrasting in brightness on the cathode ray tune. The range of signals, was found to center around twenty db difference between those signals which would normally be termed land background and those which would be termed "bright" under typical adjustments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 20, 1946
- Accession Number
- ADA801320
Entities
People
- F. N. Barry
Organizations
- Massachusetts Institute of Technology