What Is a Savitzky-Golay Filter? [Lecture Notes]

This article has attempted to answer the question "What is a Savitky-Golay filter?" in terms that will be familiar to the DSP community and readers of IEEE Signal Processing Magazine. This article reviewed the definition and properties of S-G filters and showed how they can be designed easily using polynomial approximation of an impulse sequence. In contrast to most discussions of S-G filters, they focused on the frequency domain properties, and offered an approximate formula for the 3-dB cutoff frequency as a function of polynomial order N and impulse response half length M. Engineers with a frequency domain mindset may find this useful if they choose to use S-G filters in their application.