blind-speed effect

blind-speed effect

A characteristic of Doppler MTI (moving target indicator) systems used with radars having a fixed PRF (pulse repetition frequency), which makes them blind to targets whose Doppler frequencies are multiples of PRF. This effect is utilized by aircraft to avoid detection.
blink
i. To switch off and on navigation lights twice in quick succession at night as an acknowledgment of receiving a message.
ii. Illuminating and extinguishing lights or other indications, or presenting black-and-white or other contrasting indications, for more than 20 times a minute.
iii. To switch on and off radar at short intervals.
iv. To break down as in “on the blink.”
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved