Discussion Overview
The discussion revolves around calculating spectral density from a fast Fourier transform (FFT) of a signal, specifically in the context of voltage noise. The focus is on the theoretical and practical aspects of this calculation, particularly using Fortran 90.
Discussion Character
- Technical explanation, Conceptual clarification, Debate/contested
Main Points Raised
- One participant inquires about the method for obtaining spectral density from an FFT, suggesting a focus on voltage noise.
- Another participant mentions that a power spectral density (PSD) is akin to calculating the root sum square (RSS) of the signal and suggests contacting a specific expert for further resources.
- A different participant presumes that the inquiry pertains to the power spectrum or energy spectrum, which they relate to the Fourier Transform of the autocorrelation function, and notes the importance of the magnitude squared of the FFT along with a scaling factor.
- The original poster expresses a desire to implement this calculation in Fortran 90, highlighting a specific concern regarding the scaling factor involved in the process.
Areas of Agreement / Disagreement
Participants have not reached a consensus on the exact method for calculating spectral density, and multiple viewpoints regarding the relationship between PSD, FFT, and scaling factors are presented.
Contextual Notes
There are unresolved aspects regarding the scaling factor and its application in the calculation of spectral density from FFT, as well as potential dependencies on definitions of power spectrum and energy spectrum.