Howtosignalprocessing
- What is sample spacing in FFT?
- How does sample rate affect FFT?
- How many samples needed for FFT?
- How can I make my FFT more accurate?
What is sample spacing in FFT?
The frequency spacing is 1 Hz since samples are accumulated for 1 second.
How does sample rate affect FFT?
The amplitude of the DFT (FFT) is proportional to the number of samples. Therefore, if you sample for twice as long at the same sampling frequency, or if you sample for the same duraiton but twice as fast, you will have twice as many data points, and the DFT amplitude will be twice as large. See examples below.
How many samples needed for FFT?
The number of samples (N) in the FFT must be an integer power of 2. Therefore, N = 2p, where p is a positive integer. This rule minimizes the number of multiplications—and therefore the computation time—needed to compute the coefficients of the Fourier series.
How can I make my FFT more accurate?
The most intuitive way to increase the frequency resolution of an FFT is to increase the size while keeping the sampling frequency constant. Doing this will increase the number of frequency bins that are created, decreasing the frequency difference between each.
