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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 ...
Radar transmission frequency spectrum of a cosine pulse profile. Similarly, the use of a cosine pulse profile has an even more marked effect, with the amplitude of the sidelobes practically becoming negligible. The main lobe is again increased in amplitude and the sidelobes correspondingly reduced, giving a significant improvement in performance.
Pulse width is an important measure in radar systems. Radars transmit pulses of radio frequency energy out of an antenna and then listen for their reflection off of target objects. The amount of energy that is returned to the radar receiver is a function of the peak energy of the pulse, the pulse width, and the pulse repetition frequency.
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]
Pulse-Doppler typically uses medium pulse repetition frequency (PRF) from about 3 kHz to 30 kHz. The range between transmit pulses is 5 km to 50 km. Range and velocity cannot be measured directly using medium PRF, and ambiguity resolution is required to identify true range and speed.
The MTI radar uses low pulse repetition frequency (PRF) to avoid range ambiguities. Moving target indicator (MTI) begins with sampling two successive pulses. Sampling begins immediately after the radar transmit pulse ends. The sampling continues until the next transmit pulse begins.
Areas outside the blue zones are blind ranges and blind velocities, which are filled in using multiple PRF and frequency agility. The unambiguous zone is in the lower left corner. All of the other blocks have ambiguous range or ambiguous radial velocity. Pulse Doppler radar relies on medium pulse repetition frequency (PRF) from about 3 kHz to ...
The blind velocity for a specific pulse repetition frequency (PRF) is an integer multiple of the following, which causes the signal to have zero doppler. B l i n d V e l o c i t y = ( C × P R F 2 × T r a n s m i t F r e q u e n c y ) {\displaystyle Blind\ Velocity=\left({\frac {C\times PRF}{2\times Transmit\ Frequency}}\right)}