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1 vote
Accepted

Amplitude scaling for the FFT of a logarithmic frequency sweep

Let's look at the the spectrum on a log/log scale to see what's going on You can see that the sweep starts indeed at 1Hz and goes all the way up to 5kHz. However the spectrum is not flat, but it's ...
Hilmar's user avatar
  • 45.4k
0 votes

How do you properly cut out negative frequencies from FFT of a real signal if it reduces sample size?

You mention magnitudes. You need to consider the complex numbers. For a real input vector, the $0^{th}$ bin will be real. Then for bins $0 < n < N/2$, the values will be complex, so each will ...
TimWescott's user avatar
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How do you properly cut out negative frequencies from FFT of a real signal if it reduces sample size?

By removing the negative frequency components, you're not really losing any information because they are just the complex conjugate of the positive frequency components, so they're trivial to recover. ...
Stephen's user avatar
  • 381
0 votes

very basic confusion about the bandwidth of constant signal function

Yes a constant pulse indeed occupies zero bandwidth. This is consistent with the Fourier Transform of a constant in time, which is an impulse in frequency. However that constant in time must extent as ...
Dan Boschen's user avatar
1 vote
Accepted

very basic confusion about the bandwidth of constant signal function

Usually, one would assume that the circuit is not in a transient in order to be able to talk about a "frequency analysis". So, assume that you have a DC source of K volts switched on since $...
coal's user avatar
  • 36
0 votes

very basic confusion about the bandwidth of constant signal function

You seem to be regarding two different types of signals as equivalent, yet they are not. Any signal can be decomposed into a sum of sinusoids, and the frequencies of those sinusoids define the ...
Stephen's user avatar
  • 381
0 votes

How to measure the vibration of an object on a video shot at high speed camera?

Not really anything I've done, but chapter 3 of Chen's PhD addresses a similar problem for non-contact building inspection using vibration measurements from video. The relevant chapter has this ...
Peter K.'s user avatar
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12 votes
Accepted

Why is sampling frequency/rate typically abbreviated Fs and not Sf in English?

DSP is in the end a field of math, mostly living on the intersection of analysis, linear algebra and maybe stochastics. As it describes signals, it's also a daughter of Physics. So, it uses the ...
Marcus Müller's user avatar

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