Keegs
  • Member for 4 years, 3 months
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  • Huntsville, AL, United States
What is the transfer function of the filtfilt?
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The MATLAB documentation for filtfilt() links to a brief explanation of the concept. It seems they use an anti-causal version of the original filter to "rectify" to zero-phase. I imagine if ...

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How can radars find the elevation angle of a target?
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Generally, before Phased Array antennas, they would use the amplitude of the target response to give a very rough estimation of altitude. By accounting for all the losses not due to where the target ...

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How to objectively measure how "good" a time-frequency representation of music is?
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There is a fundamental tradeoff between frequency resolution and time resolution. The more granular you want your measurements in time, the less frequency distinction there is in each time bin. ...

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Why does cross correlation need minimum number of 5000 samples for correct time delay estimation?
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Two things that might help, though I can't be sure without those files. You need to be finding the max of the absolute value of the cross-correlation because the phase of the correlation output in ...

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SNR and "Sampling Error"
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2 votes

There is a somewhat more fundamental issue with delay/range estimation in this scenario, of which you haven't made mention, and that is the inherent phase ambiguity when trying to match two continuous-...

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Faster way to Implement a CFAR (window average) Threshold
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The easiest way to accelerate this would be to eliminate as many for-loops as you can and instead refactor to use array operations on your data. Check the help page for arrayfun() as well; it's a ton ...

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If video uses color bars to test and align color values among TV sets, what could be the equivalent in Audio?
1 votes

If you want the AI to relate to how we perceive sound, maybe something like a linear chirp from 20Hz-20kHz white noise in the same bandwidth a single sine wave at 1kHz (roughly our greatest ...

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How exactly do I plot a constellation Diagram?
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Typically a constellation diagram is not just the raw RF values because that would be extremely disorganized. You would end up with a bunch of points in a gaussian distribution about the origin (...

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Comparing two small audio files (e.g., hand clap) Android
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What you're interested in sounds like a generic version of a matched filter. I'm not going to be able to speak to the software aspect of how you implement the file handling and "always-on" ...

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What is the importance of signal bandwidth in radar systems for velocity and localization estimation
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1 votes

Bandwidth affects the "gate/cell width" of your measurements. If you think about an LFM waveform reflecting back off an object and going through a matched filter to determine the range, a ...

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Deconvolution Question on Article "Deriving Intrinsic Images from Image Sequences" by Yair Weiss
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I'm struggling a little with this notation because I don't usually do any significant image processing. Many LTI filters have an inverse and it seems like this is where your discussion is leading. I'm ...

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Side lobe reduction
1 votes

If you want to reduce sidelobes and are willing to accept lobe width increase, I'd suggest a Taylor window. Applying it to an image instead of a time-domain signal should not be an issue, so long as ...

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Sampling the Wave Equation for String Vibration
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Assuming I understand the question correctly, you need to sample the string's position at least twice as fast as the maximum frequency you anticipate the string can move or the highest frequency you ...

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How do I time-stretch a signal from the frequency domain?
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Say the FFT array is X[0:N-1]. What you want to do is something like this for n in range(S * N): if mod(n,S) == 0: Y[n] = S*X[n/S] else: Y[n] = 0; y = ifft(Y) Effectively you ...

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Finding the Sections of Signals that are the Most Similar
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The best way to achieve this, to my knowledge, is a matched filter or cross-correlation. This will tell you not only how well $A$ and $B$ match but will also give you a time offset for it. Just make ...

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low pass filter in fft
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I need to see the code behind your graph because the numbers you put down are not making sense with that figure. Your graph should cover X values from 1-12501 if it's just FFT indices or 0-1250 for ...

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Time invariance of a System
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2 votes

Yes, this system is time-invariant assuming $x[n]\neq0 $ for all $n $. The test for this is $$x_{1}[n]=x[n-n_{0}] $$ $$y_{1}[n]=y[n-n_{0}] $$ So let's first express in terms of just $y[n]$. $$ y[n]=\...

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Is there anything called uncorrelated filter?
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No filter I know of will accomplish this reduction in autocorrelation without sacrificing major signal components. If you want something to go from having significant autocorrelation (for k~=0 ...

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Can anyone help me with good reference books for Discrete Wavelet Transform (DWT)
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(Some of this may belong in a comment, but I apparently can't do that) I highly suggest Computer-Based Exercises for Signal Processing Using MATLAB (McClellan, Burrus, Oppenheim, Parks, Schafer). It ...

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Audio DSP HW Recommendation
1 votes

I've used one of the miniDSP kits (actually three USB Streamers) in a design project, and it did perform well, but we never did any of the actual DSP onboard and instead relied on computer software. ...

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