
Signal-Processing Methods in Phase-Shifting Interferometry ◾ 245
the limit of 2π/N and depends on the sample autovariance matrix, noise
level, and number of frequencies NOF generated between the interval
[0, 2π). Hence, for the same number of data frames N, the frequency resolu-
tion is 2π/NOF. Because the method performs the Fourier transform with
enhanced resolution, the method is referred to as a superresolution Fourier
transform (SRFT) method. e superresolution property of the method is
demonstrated using the examples in Boxes 7.1 and 7.2. ese illustrations
BOX7.1 COMPARISON WITH DFT METHODS (𝛋 = 1)
In Example 7.1, we considered a ...