TM 11-5841-283-12
GLOSSARY
The following special words and terms are used in this manual.
ALARM AUDIO. A varying high-low warning tone sounded at a 2.5 Hz rate. Alarm sounds with a
frequency of 1100 Hz and stops with a frequency of 700 Hz.
CRT (cathode ray tube).
Radar signal indicator screen. Shows aircraft operator the presence of
a signal.
LINE-OF-BEARING. A direction to an emitter or tracking device with respect to aircraft heading.
Direction is displayed by a radial strobe on the indicator CRT.
PERSISTENCE. The number of pulses present in a pulse train in a specified period of time.
Persistence is expressed as a percentage.
PULSE. An abrupt change in voltage (either positive or negative), which conveys information to a
circuit.
PULSE CORRELATION. The time relationship between pulses of high band and low band intercepts.
Pulses are correlated when the low band trailing edge leads the high band leading edge by a
specified time.
PULSE REPETITION FREQUENCY (PRF). The audio tone generated by mixing the high band videos.
PULSE REPETITION INTERVAL (PRI). Also known as pulse repetition period (PRP). The interval or
period expressed as a unit of time, between the leading edges of sequential pulses in a train.
PRI=1/PRF
PULSE TRAIN. A repetition of pulses.
Glossary 1/(Glossary 2 Blank)