Im reading a book about DSP and there is an example about investigating the sound that travel through the ocean. The sound was recorded as the time-domain signal and they tried to analyze it in frequency domain.
The input signal was broke up into 256 point segments. Each of these segments is multiplied by the Hamming window, then run through a 256 point DFT. The resulting frequency spectra are then averaged to form a single 129 point frequency spectrum. Please take a look at the figure
I don't understand:
How they break up the input signal into 256 segments?
How each segment was multiplied with the Hamming window?
How they calculate 256 DFT points?
How the frequency spectra was averaged?