Determination of spectral profiles from correlation measurements

Abstract

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 using exponential 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.