Sampling and Aliasing Problem
C) If you sample for one second, your FFT resolution will be 1Hertz. Because you can precisely correlate[with no missing and no extra samples] with a 1Hz sine/cosine basis set. 1.1Hertz does not accurately peak/null with 1.000 second time series. Nor does 1.5 second. However 2.0 second does. 2.5 second does not. 3.0 second does. Examine the sin(x)/x curve, which is exactly the output of a correlation (multiply &amp; integrate) of rectangle with sinusoid.

D) Given Fmin_sample is 29 Hz, there will be folding if only 20Hz is used.
The 4.77Hz is correctly represented.
But the 14.33 will be aliased. To where? It is 4.33Hz above the 10Hz Ffold.

In this example of ADC F_in/Magnitude_in, we see the down-conversion and folding. Fsample is 20.00Hz.







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