Summary
From correlation measurements one can determine the modulus |γ(τ) | (for real τ) of the copherence function which is the Fourier transform of the spectral density. It is shown that by usingexponential filters one can determine |γ(τ)| for complex τ also. From these measurements and using analytic properties of γ(τ), one can determine γ(τ) (i.e. its phase also) and hence the spectral density.
Riassunto
Con misure di eorrelazione si può determinare il modulo |γ(τ)| (per τ reale) della funzione di coerenza che è la trasformata di Fourier della density spettrale. Si dimostra che usandofiltri esponenziali si può determinare |γ(τ)| anche per τ complesso. Da queste misure ed usufruendo delle proprietà analitiche di γ(τ) si può determinare γ(τ) (cioè anche la sua fase) e quindi la densità spettrale.
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This research was supported by the Army Research Office, Durham.
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Mehta, C.L. Determination of spectral profiles from correlation measurements. Nuovo Cim 36, 202–205 (1965). https://doi.org/10.1007/BF02750672
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DOI: https://doi.org/10.1007/BF02750672