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Pulse compression is a signal processing technique commonly used by radar, sonar and echography to either increase the range resolution when pulse length is constrained or increase the signal to noise ratio when the peak power and the bandwidth (or equivalently range resolution) of the transmitted signal are constrained.
The chirp pulse compression process transforms a long duration frequency-coded pulse into a narrow pulse of greatly increased amplitude. It is a technique used in radar and sonar systems because it is a method whereby a narrow pulse with high peak power can be derived from a long duration pulse with low peak power.
A Barker code resembles a discrete version of a continuous chirp, another low-autocorrelation signal used in other pulse compression radars. The positive and negative amplitudes of the pulses forming the Barker codes imply the use of biphase modulation or binary phase-shift keying; that is, the change of phase in the carrier wave is 180 degrees.
The Fresnel ripples on a chirp spectrum are very obtrusive, especially when time-bandwidth products are low (under 50, say) and their presence leads to high time sidelobe levels when chirps are subject to pulse compression as in radar and sonar systems. They arise because of the sudden discontinuities in the chirp waveform at the commencement ...
Pulse compression is an example of matched filtering. It is so called because the impulse response is matched to input pulse signals. Two-dimensional matched filters are commonly used in image processing, e.g., to improve the SNR of X-ray observations. Additional applications of note are in seismology and gravitational-wave astronomy.
Chirp compression - Further information on compression techniques; Chirp spread spectrum - A part of the wireless telecommunications standard IEEE 802.15.4a CSS; Chirped mirror; Chirped pulse amplification; Chirplet transform - A signal representation based on a family of localized chirp functions. Continuous-wave radar; Dispersion (optics ...
The stretching and compression uses devices that ensure that the different color components of the pulse travel different distances. CPA for lasers was introduced by Donna Strickland and Gérard Mourou at the University of Rochester in the mid-1980s, [2] work for which they received the Nobel Prize in Physics in 2018. [3]
Prismatic pulse compression was first introduced, using a single prism, in 1983 by Dietel et al. [1] and a four-prism pulse compressor was demonstrated in 1984 by Fork et al. [2] Additional experimental developments include a prism-pair pulse compressor [3] and a six-prism pulse compressor for semiconductor lasers. [4]