I am trying to find out the transfer function of a real life continuous-time black box.
First thought is of course to input a delta and get the impulse response as the books have taught us but I think it is not feasible as you can't have a proper delta (infinite at one point).
Q1. How can I simulate a Dirac input in a way that I don't break my system and in a way that it is going to give me a pretty accurate result? Accurate meaning something that will look a lot like the impulse response.
Second thought is to do a frequency response analysis where I will input a few sinusoids at different frequencies and store the output.
Q2. How many periods should I gather for each sinusoidal so that I get an accurate output?
Q3. What effect would a few leading zeros on my input have on my output spectrum? Is it going to be the same as zero-padding?
A3. Yes, because zero-padding the input will lead to zero-padding the output which I will then FFT.
Q4. If the input signal stops abruptly and went to zero after a sufficient signal length time, would that discontinuity affect my output spectrum as well?