scientimate.pmpsd

f, Syy, Hm0, fp, Tp, Tm01, Tm02 = scientimate.pmpsd(U195=10, fp=0.33, fs=2, N=256, CalSpectralSP='yes', dispout='no')

Description

Calculate Pierson-Moskowitz spectrum (power spectral density), (Pierson and Moskowitz 1964)

Inputs

U195=10

Wind velocity at 19.5 meter above surface level in (m/s)

fp=0.33

Peak wave frequency (fp=1/Tp) in (Hz)

If CalSpectralSP=’yes’; then fp is calculated from U195

fs=8

Sampling frequency that data collected at in (Hz)

N=256

Total number of points between 0 and fs that spectrum reports at is (N+1)

CalSpectralSP=’yes’

Define to calculate spectral shape parameters or not (‘yes’: calculate, ‘no’: use given parameters by user)

dispout=’no’

Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs

f

Frequency (Hz)

Syy

Wave Energy Power Spectrum (m^2/Hz)

Hm0

Zero-Moment Wave Height (m)

fp

Peak wave frequency (Hz)

Tp

Peak wave period (second)

Tm01

Wave Period from m01 (second), Mean Wave Period

Tm02

Wave Period from m02 (second), Mean Zero Crossing Period

Examples

import scientimate as sm
f,Syy,Hm0,fp,Tp,Tm01,Tm02=sm.pmpsd(10,0.33,2,256,'yes','yes')

References

Pierson, W. J., & Moskowitz, L. (1964). A proposed spectral form for fully developed wind seas based on the similarity theory of SA Kitaigorodskii. Journal of geophysical research, 69(24), 5181-5190.