Results 231 to 240 of about 436,878 (286)

Instantaneous spectra and instantaneous frequency

Proceedings of the IEEE, 1970
A simple relation exists between the instantaneous frequency and the instantaneous spectrum of an analytic signal which does not depend on an assumption that the instantaneous frequency varies slowly.
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Microprocessor-based instantaneous frequency meter

Electroencephalography and Clinical Neurophysiology, 1981
Abstract An instantaneous frequency meter employing a 6502 microprocessor (Rockwell AIM 65) is described. it features low cost, linearity, and flexibility, allowing software control of sensitivity.
S, Iscoe, R A, Young
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Instantaneous frequency and time-frequency distributions

1995 International Conference on Acoustics, Speech, and Signal Processing, 2002
It is generally stated that the conditional mean frequency of a time-frequency distribution (TFD) should equal the instantaneous frequency of the signal. The commonly accepted definition of instantaneous frequency as the derivative of the phase of the analytic signal sometimes leads to curious results.
B. Tacer, P.J. Loughlin
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Instantaneous frequency and its instantaneous deviation

Journal of Modern Optics, 2004
Using statistical language, the instantaneous frequency of a deterministic signal, such as an electromagnetic pulse collected at a point in space, is a location function and its deviation is a shape function. The former is better defined than the latter, which can be computed an infinity of different ways, some of which can exhibit pathologies.
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Instantaneous frequency and time-frequency distributions

IEEE International Symposium on Circuits and Systems, 2003
A discussion of instantaneous frequency from the point of view of joint time-frequency distributions is presented. From this perspective, instantaneous frequency is the average frequency at a particular time. This view forces the consideration of the standard deviation of instantaneous frequency at a given time.
L. Cohen, C. Lee
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Anisotropic Instantaneous Frequency Estimator

2019 IEEE International Conference on Signal Processing, Communications and Computing (ICSPCC), 2019
We present a novel transform, called anisotropic chirplet transform, for the time-frequency analysis of overlapping signals. This transform is motivated by a desire to characterize micro-Doppler signals from the continuous wave radars, especially a challenging topic for instantaneous frequency (IF) estimation in high noise environments.
Yongchun Miao, Haixin Sun, Junfeng Wang
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CIRCULAR INSTANTANEOUS FREQUENCY

Advances in Adaptive Data Analysis, 2010
This work defines the unique instantaneous frequency (IF) of an arbitrary time signal to be the circular instantaneous frequency (cIF) of the curvature radius of the signal's trajectory on the phase plane, where the signal's conjugate part is obtained from Hilbert transform (HT).
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Instantaneous frequency spectra

The Leading Edge, 2015
The goal of performing spectral decomposition is to determine the frequency spectra of the seismic signal as a function of traveltime. In conventional short-window Fourier methods and in continuous-wavelet transforms, there is a trade-off between temporal resolution and frequency resolution. By using a new method, spectral decomposition can be obtained
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Instantaneous frequency: Reply

The Leading Edge, 1992
Phasors or formulas? In this article, I used a phasor representation to indicate why the instantaneous frequency of a seismic trace can be negative and why it can be unstable when the amplitude envelope is small. The equivalent algebraic representation of the analytic signal is well known and some may prefer it, but I considered that phasors gave the ...
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Instantaneous frequency measurement

Medical Electronics & Biological Engineering, 1963
A method is outlined for obtaining an indication of instantaneous frequency by a computation of the reciprocal of the time for one period. This is accomplished by the discharge of a condenser through an element having current proportional to the square of the voltage. The square law element consists of a biased diode network.
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