How does Moku:Lab calculate the Power Spectral Density?

PSD and ASD calculation in the Phasemeter

In Moku:Lab's Phasemeter, Power Spectral Density (PSD) and the Amplitude Spectral Density (ASD) are calculated in the iPad App using Welch’s method of overlapping periodograms with a 50% overlap and a Hanning window. The number of points is either 512, 1048 or 2048 depending on the sampling rate chosen.

A Python-based example of a similar algorithm can be found here.