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I have an accelerometer data i.e. AccX, AccY and AccZ.

I am looking for an algorithm to compute Power Spectral Density from this data. I know the following:

F = fft (s);

where "s" is the input signal and fft is fast fourier transform.

PSD = (1/length(s)) * F * conj(F);

I need to know that whether this s should be acceleration-time series or position-time series?

Harald K
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VikramBishnoi
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    Seems to me that NASA uses the acceleration:http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19970034695.pdf But read this doc for yourself, I am not an expert here. – Jacques de Hooge Jul 10 '15 at 14:02

1 Answers1

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It depends on what you are interested in. If you want the power spectral density of the acceleration time-series, then s must be the acceleration time-series itself and not the position time-series. Note however that the estimate of the PSD based on that simple algorithm you wrote (called "periodogram") may be insufficient in many cases, to get a realistic estimate of the real PSD. The topic is huge, and literature extensive. You can start from Wikipedia or, if you want a suggestion on a good (but rather tough) book, Percival and Walden. To provide more detailed info, one would need to know much more in detail what you have to do from a physical point of view.

ajc
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