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Radar transmission frequency spectrum of a trapezoid pulse profile Recent advances in signal processing techniques have made the use of pulse profiling or shaping more common. By shaping the pulse envelope before it is applied to the transmitting device, say to a cosine law or a trapezoid, the bandwidth can be limited at source, with less ...
The pulse-repetition frequency (PRF) is the number of pulses of a repeating signal in a specific time unit. The term is used within a number of technical disciplines, notably radar. In radar, a radio signal of a particular carrier frequency is turned on and off; the term "frequency" refers to the carrier, while the PRF refers to the number of ...
Pulse-Doppler radar for aircraft detection has two modes. Scan; Track; Scan mode involves frequency filtering, amplitude thresholding, and ambiguity resolution. Once a reflection has been detected and resolved, the pulse-Doppler radar automatically transitions to tracking mode for the volume of space surrounding the track.
Pulse Doppler radar may have 50 or more pulses between the radar and the reflector. Pulse Doppler relies on medium pulse repetition frequency (PRF) from about 3 kHz to 30 kHz. Each transmit pulse is separated by 5 km to 50 km distance. Range and speed of the target are folded by a modulo operation produced by the sampling process. True range is ...
The AN/AWG-9 and AN/APG-71 radars are all-weather, multi-mode X band pulse-Doppler radar systems used in the F-14 Tomcat, and also tested on TA-3B. [1] It is a long-range air-to-air system capable of guiding several AIM-54 Phoenix or AIM-120 AMRAAM missiles simultaneously, using its track while scan mode.
Early Doppler radars included CW, but these quickly led to the development of frequency modulated continuous wave radar, which sweeps the transmitter frequency to encode and determine range. With the advent of digital techniques, Pulse-Doppler radars (PD) became light enough for aircraft use, and Doppler processors for coherent pulse radars ...
Range ambiguity resolution is a technique used with medium pulse-repetition frequency (PRF) radar to obtain range information for distances that exceed the distance between transmit pulses. This signal processing technique is required with pulse-Doppler radar. [1] [2] [3]
The fire-control radar must be directed to the general location of the target due to the radar's narrow beam width. This phase is also called "lighting up". [3] It ends when lock-on is acquired. Acquisition phase The fire-control radar switches to the acquisition phase of operation once the radar is in the general vicinity of the target.