Timeline for What's the ideal FFT window for measuring a group of signals of differing amplitudes but close in frequency?
Current License: CC BY-SA 4.0
12 events
| when toggle format | what | by | license | comment | |
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| Dec 13, 2020 at 18:50 | history | edited | Ben S. | CC BY-SA 4.0 |
added information about the setup and I guess more detail about what quantities I need
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| Dec 13, 2020 at 18:49 | comment | added | Ben S. | @DanBoschen apparently I need to edit my OP. I know the wavelengths of the lasers. That's not what I'm measuring. I need to recover their amplitudes and phases when I chop them with TTL modulation, after they're attenuated by the medium I'm analyzing. Spectral properties of the lasers don't factor in to this whatsoever. | |
| Dec 13, 2020 at 12:57 | comment | added | Dan Boschen | @BenS. I highly doubt the line width of your lasers is less than 4 Hz to be able to distinguish tones spaced that close | |
| Dec 12, 2020 at 15:58 | answer | added | IanJ | timeline score: -1 | |
| Dec 12, 2020 at 13:06 | answer | added | Hilmar | timeline score: -1 | |
| Dec 12, 2020 at 1:54 | answer | added | Dan Boschen | timeline score: 1 | |
| Dec 11, 2020 at 23:04 | comment | added | Ben S. | @IanJ I'm doing I/Q demodulation as implemented in the linked question. Do you have a good starting point for where to investigate non-FFT routes? I'm not a DSP guy in general, I've only used the I/Q demodulation stuff in practice. | |
| Dec 11, 2020 at 22:48 | comment | added | IanJ | Are you are actually demodulating or just doing a carrier recovery / baseband translation. I agree that FFTs aren't what you want to do. It sounds like you would want to do some matched filtering. You want to design your signals so that they are orthogonal to each other. | |
| Dec 11, 2020 at 18:07 | history | edited | Ben S. | CC BY-SA 4.0 |
more detail about my measurement needs
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| Dec 11, 2020 at 18:06 | comment | added | Ben S. | @Hilmar I need to measure the amplitudes and phases of the lasers. I know the frequencies and can control them. | |
| Dec 11, 2020 at 18:03 | comment | added | Hilmar | What exactly do you need to measure and what do you know? Frequency, amplitude, phase, drift, jitter ? It seems tome that FFT is really the wrong tool for this type of problem. | |
| Dec 11, 2020 at 17:46 | history | asked | Ben S. | CC BY-SA 4.0 |