Time averaged wavelet spectral density in magnitude^2/Hz

Hi,

I am using the following function in wavelet toolbox to obtain the time averaged/global wavelet spectral density.

timeSpectrum(fb,sm,'SpectrumType','density','Normalization','var')

It produces the spectral density in magnitude^2/scales. I need the spectral density in magnitude^2/Hz. I tried to convert the scales to frequencies by the conversion. freq(Hz) = centerfreq(morse)/scales.

centerfreq(morse) = (P^2/γ)^1/γ, P = 60, γ=3.

However, it produced erroneous results. Any help on getting the global wavelet spectral density in magnitude^2/Hz will be much appreciated.

Thank You

Answer 1

[Ayush]

Hi,

It seems like you are trying to convert the scales to frequencies when dealing with global wavelet spectral density.

You can refer to the function, "scal2frq", which returns the pseudo-frequencies corresponding to the scales and the wavelet specified. This function also allows you to specify the sampling period as a parameter. The basic syntax for this function is:

freq = scal2frq(A, wname, delta);

Where "A" is scales, "wname" is wavelet and "delta" is sampling period.

For more information on "scal2frq" function and "Morse wavelet" given in the question, refer to the documentations below.

• "scal2frq": https://www.mathworks.com/help/wavelet/ref/scal2frq.html
• "Morse wavelet": https://www.mathworks.com/help/wavelet/ug/morse-wavelets.html

I hope it helps!