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In the United States a longer duty cycle is used, 50% for battery-powered buoys (20 seconds on, 20 seconds off) and 75% for on-shore beacons. Ramarks are wide-band beacons which transmit continuously on the radar bands without having to be triggered by an incoming radar signal. The transmission forms a line of Morse characters on the display ...
Identification, friend or foe ( IFF) is a combat identification system designed for command and control. It uses a transponder that listens for an interrogation signal and then sends a response that identifies the broadcaster. IFF systems usually use radar frequencies, but other electromagnetic frequencies, radio or infrared, may be used. [1]
Pulse-repetition frequency (PRF) is the number of times a pulsed activity occurs every second. This is similar to cycle per second used to describe other types of waveforms. PRF is inversely proportional to time period which is the property of a pulsed wave. PRF is usually associated with pulse spacing, which is the distance that the pulse ...
The air traffic control radar beacon system ( ATCRBS) is a system used in air traffic control (ATC) to enhance surveillance radar monitoring and separation of air traffic. It consists of a rotating ground antenna and transponders in aircraft. The ground antenna sweeps a narrow vertical beam of microwaves around the airspace.
The duty cycle is defined as the ratio between the pulse duration, or pulse width ( ) and the period ( ) of a rectangular waveform. Spectrum in relation to duty cycle. A duty cycle or power cycle is the fraction of one period in which a signal or system is active. [1] [2] [3] Duty cycle is commonly expressed as a percentage or a ratio.
A pulse-Doppler radar is a radar system that determines the range to a target using pulse-timing techniques, and uses the Doppler effect of the returned signal to determine the target object's velocity. It combines the features of pulse radars and continuous-wave radars, which were formerly separate due to the complexity of the electronics .
The pulse width ( ) (or pulse duration) of the transmitted signal is the time, typically in microseconds, each pulse lasts. If the pulse is not a perfect square wave, the time is typically measured between the 50% power levels of the rising and falling edges of the pulse. The pulse width must be long enough to ensure that the radar emits ...
This system, which became known in civil use as secondary surveillance radar (SSR), or in the US as the air traffic control radar beacon system (ATCRBS), relies on a piece of equipment aboard the aircraft known as a " transponder ." The transponder is a radio receiver and transmitter pair which receives on 1030 MHz and transmits on 1090 MHz.