Power spectral density

Power spectral density procedure

1. PSD Spectrum

Acceleration time history )(tA

Fourier transform of 



 dtetAfA
ftj2
)()(

Power Spectral Density 


 dffAPSD
2
)(

Code: psd[i] =
Math.sqrt(2.0*accFamp[i]*accFamp[i]*df*0.0001)/9.8*1000000.;//micro G/sqrt(Hz)

In terms of dB 2
2
10
sec/1
))
)(
((log10
mAwhere
df
A
fA
PSD
ref
ref
dB




PSD_rms = Root-Mean-Square(PSD)*sqrt(1.6*(f2-f1)) for frequency range (f1~f2)
PSD_rms = Root-Mean-Square(PSD)*sqrt(f2-f1) for frequency range (f1~f2)