Simple and tested periodogram normalizations for astronomical time-series
pip install periodogram
There are three types of normalizations available. The amplitude spectrum is normalized such that a sine wave of amplitude 1 will have a peak amplitude of 1. The power spectrum will have 1^2, and the power spectral density will have 1^2 * Tobs
from periodogram import Periodogram
p = Periodogram.calculate(x, y, normalization='amplitude')
p.plot()
Lower-level functions for directly calculating different normalizations are also available
from periodogram import amplitude_spectrum, psd, power_spectrum
frequency, amplitude = amplitude_spectrum(x, y)