Window (signal processing)

In signal processing, a window is used to analyze a finite amount of data in the frequency domain. Various types of windows (and the size of the first side-lobe) are the following:

• rectangular window: -13 dB (is the same as "not using a window")
• Bartlett window -27 dB (triangular: 0 at ends, 1 at center)
• Bartlett-Hanning window -32 dB (raised cosine: 0 at ends, 1 at center)
• Blackman window -58 dB (2 cosine waves ... 0 at ends, 1 at center)
• Blackman-Harris window
• Bohman window
• Chebyshev window
• Gaussian window
• Hamming window -43 dB (raised cosine: +0.08 at ends, 1 at center)
• Hann window
• Kaiser window (... uses a Bessel function ...)
• Tukey window

The rectangular window gives the best frequency accuracy (narrowest main lobe) at the cost of the highest side-lobes. The Blackman window gives the lowest side-lobes at the cost of the widest main lobe.