All Questions
Tagged with signal-processing data-analysis
14
questions
2
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0
answers
43
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How to extract the "matter fluctuation amplitude" from the CMB power spectrum?
How do you convert the value listed in Planck 2018 results. VI. Cosmological parameters, $A_s = 2.101\times10^{-9}$ to the value of the matter fluctuation amplitude $\sigma_8=0.8111$? I tried ...
- 21
0
votes
1
answer
33
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What relationship between the time recording length and the frequency bandwidth?
In model testing for ocean waves, the data recording duration is usually longer the better especially for irregular waves. The recording length shall be long enough to achieve sufficiently small ...
- 138
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20
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Does it make sense to whiten the data in order to apply a matched filtering algorithm if my dataset consist of a sinusoid + random Gaussian noise?
With a Python program I generated a sinusoid signal and I added to it Gaussian noise.
Now I want to compute the optimal SNR by applying a matched filtering algorithm.
Since the noise is white (at ...
0
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0
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38
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How to "classify" signals?
I have some signals and I want to classify them into different types. Signals are all sine shape signals, some might have glitches. I know I could classify them base on frequency or amplitude, but is ...
- 13
1
vote
1
answer
85
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Evaluate action of $f(\frac{d}{dx})$ using the Fourier/Laplace transform
Initially I asked this question on mathoverflow. I however thought physicists may face this sort of problem more than mathematicians (I am an engineer). Due to that, I decided to ask here as well.
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- 213
0
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43
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FFT on a signal with a length that is not a multiple of the period of its harmonics
I was very surprised to find an apparent limitation to a FFT on a simple signal.
Let's consider a timeseries made of L=100 points, and simply composed of the sum of two sinus waves: one with a ...
- 127
1
vote
1
answer
181
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Power Spectrum Density of real valued time series data
There are real valued time-series data X(t) and corresponding auto-correlation function ACF(t)=$\left<X(0)X(t)\right>$. As written in wikipedia, Power Spectrum Density (PSD) can be calculated ...
- 103
0
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1
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43
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How do low voltage differential signals transmit bits
For example: There is Din+ connected to pin a1 and Din- to pin a2. Suppose I am sending "0101". How does it get sent?
If there was only Din connected to Pin a1, which has a voltage supply to the bank ...
- 3
0
votes
1
answer
59
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Subtracting Audio from a Song with Multiple Forms
This question may start oozing into the realm of copyright infringement, but let's discuss the theory first and foremost.
I have a song with vocal and orchestral accompaniment from a well-known movie ...
- 109
1
vote
1
answer
422
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Normalizing temperature data of CPU sensors to ambient [closed]
My scenario:
I want my application to stop or take some decision based on temperature. say like if my ambient is morethan 41 i want to switch off the application and we do not have an separate ...
- 119
1
vote
1
answer
53
views
Karhunen-Loeve transform of a repeating process
This question is inspired by measurements of an unsteady flow. I have some doubts about interpretation of principal component transform using Karhunen-Loeve theorem.
I have (centered $\equiv$ zero ...
- 2,824
5
votes
1
answer
3k
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White Noise Generator Through Low Pass Filter - Autocorrelation of normalized data dropping below 0 (showing negative correlation)
I am doing the following experiment:
http://physlab.lums.edu.pk/images/a/ab/Correlation.pdf
It is basically a white noise generator running through a low pass filter. Sample voltages are taken and ...
- 83
0
votes
0
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281
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Measuring typical distance between patches using 2D Fourier Transform
I need to extract information about the typical distance between the black patches in an image like the one I attached here. I tried to perform 2D FFT on it (using OpenCF fdt function in Python), but ...
- 133
4
votes
1
answer
1k
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How to determine frequency components present in distorted signal, with the set of possible components already known?
I am trying to choose the best approach to digitally analyse a signal, which is a mix of an unknown number (but less than 16) fundamental signals at specific frequencies (e.g., sines).
The goal is ...
- 141