A Savitzky-Golay (SG) filter is a digital filter that can be used to smooth data and remove noise. It works by fitting a low-degree polynomial to a window of adjacent data points and then replacing the center data point with the fitted value. The window size is determined by the order of the polynomial and the desired cutoff frequency of the filter.

Advantages of Savitzky-Golay filters:

• They have a flatter frequency response than other smoothing filters, such as moving averages. This means that they preserve more of the signal while suppressing noise.
• They can be used to calculate derivatives of data without introducing significant distortion.
• They are relatively easy to implement and can be used with a variety of programming languages and software packages.

Disadvantages of Savitzky-Golay filters:

• They can be computationally expensive, especially for high-order polynomials and long data sets.
• They can be sensitive to the choice of polynomial order and window size.

How to use a Savitzky-Golay filter to remove noise from your signal:

Is a Savitzky-Golay filter better than adjacent averaging?

In general, Savitzky-Golay filters are better at removing noise while preserving the signal than adjacent averaging. However, they are also more computationally expensive.

Adjacent averaging is a simple and efficient way to smooth data. It works by replacing each data point with the average of itself and its neighbors. However, adjacent averaging can also distort the signal, especially for high-frequency signals.

Savitzky-Golay filters are more sophisticated than adjacent averaging and can provide better results, especially for noisy data. However, they are also more computationally expensive.

Which filter is better for you depends on your specific needs. If you need a simple and efficient filter, then adjacent averaging may be a good choice. If you need a filter that can remove noise while preserving the signal, then a Savitzky-Golay filter may be a better choice.

A moving average fits a constant value over the window of the FIR filter.

An SG filter is a generalisation of this approach and fits a polynomial.