**Spectral Density**

In statistical signal processing, statistics, and physics, the spectrum of a time-series or signal is a positive real function of a frequency variable associated with a stationary stochastic process, or a deterministic function of time, which has dimensions of power per hertz (Hz), or energy per hertz. Intuitively, the spectrum decomposes the content of a stochastic process into different frequencies present in that process, and helps identify periodicities. More specific terms which are used are the **power spectrum**, **spectral density**, **power spectral density**, or **energy spectral density**.

Read more about Spectral Density: Explanation, Preliminary Conventions On Notations For Time Series, Motivating Example, Estimation, Properties, Related Concepts

### Other articles related to "spectral density, spectral":

**Spectral Density**- Applications - Coherence

... See Coherence (signal processing) for use of the cross-spectral density. ...

... with the same mean, covariance function, and power

**spectral density**as above ... We factor the power

**spectral density**as described above ... process with zero mean and constant, unit power

**spectral density**Note that this power

**spectral density**corresponds to a delta function for the covariance function of ...

... The propagators in real and imaginary time can both be related to the

**spectral density**(or

**spectral**weight), given by where refers to a (many-body) eigenstate of the grand-canonical Hamiltonian ... The

**spectral density**can be found very straightforwardly from, using the Sokhatskyâ€“Weierstrass theorem where denotes the Cauchy principal part ... The

**spectral density**obeys a sum rule which gives as ...

... to generate a frequency spectrum or

**spectral density**... The power

**spectral density**is a frequency-domain description that can be applied to a large class of signals that are neither periodic nor square-integrable to have a power ...

**Spectral Density**Estimation

... In statistical signal processing, the goal of

**spectral density**estimation is to estimate the

**spectral density**(also known as the power spectrum) of a random signal from a sequence ... Intuitively speaking, the

**spectral density**characterizes the frequency content of the signal ... The purpose of estimating the

**spectral density**is to detect any periodicities in the data, by observing peaks at the frequencies corresponding to these periodicities ...

### Famous quotes containing the word spectral:

“How does one kill fear, I wonder? How do you shoot a spectre through the heart, slash off its *spectral* head, take it by its *spectral* throat?”

—Joseph Conrad (1857–1924)