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1500 questions
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How does sensor fusion work? I want to understand the math/physics/algorithms

Sensor fusion algorithms can give a more precise 3D orientation (and possibly postion?) of a device by combining readings from an accelerometer, gyroscope, and magnetometer. Can anyone explain, or provide links, explaining the details behind this?…
YoungMoney
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Kalman Filter Covariance

I've recently started playing with the Kalman filter for a simple 2D (x,y,dx,dy) tracking toy problem. But I seem to have some misunderstanding on what I can expect from the filter. I'm interested in plotting the uncertainty ellipse from the…
Nghia
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Why the RMS of a PSD curve is the root of the area below

I will try to explain what is my level of understanding of this problem, please correct me if I'm wrong: RMS is the Root Mean Square, it represent the mean value of the input signal. PSD is the measurement of the responses that shows me at which…
Sturm
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Can a state space model have changing state size over time?

I have worked with state space models in relation to Kalman estimation. Here I have always seen state space models with fixed state size over time, i.e. the state transition matrix is square. Let us for example define: $$x_{t+1} = A_t x_t + B_t…
Thomas Arildsen
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what exactly does scale mean in scale-space theory?

In image processing, scale-space is a technique to represent an image at different scales. But this really confuses me, since I always think that the word scale just means the size of an object, so the scale-space representation of an image shall…
avocado
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Understanding Q formats

I have some misunderstandings with Q format. Please help me in understanding this. If I say Q8 [unsigned] then there will be $8$ fractional bits. Is it ? How can I represent a $1$ and $1.5$ in this case? If I say Q8 [ signed ] then there will be…
rajez79
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Precisions on Hilbert Huang transform

After investigating signal analysis methods based on empirical mode decomposition (EMD), I found that recent developments are mostly related to the Hilbert Huang transform (HHT) and the Local Mean Decomposition (LMD) method. I have been reading a…
Alain
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Zero Padding in FFT

whats is the effect of pading zeroes to a sequence in FFT? for eg: x[n]=[2 3 4 5] corresponds to X[K]=[14 -2+2i -2 -2-2i] while x[n]=[2 3 4 5 0 0 0 0] corresponds to X[K]=[14 0.58-9.65i -2+2i -3.414+1.65i -2 3.414-1.65i -2-2i 0.58+9.65i] so what is…
Kaustubh
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Jigsaw puzzle: isolating the pieces (separating "stuck" blobs)

I'm new to image processing, and I'm trying to get my feet wet. I have taken a picture of some jigsaw puzzle pieces and I want to isolate the pieces. I am using the Python SimpleCV library to do this, and so far I've managed to get pretty decent…
Avi Romanoff
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DFT and multiplication/convolution equivalence

Is there a simple or potentially intuitive explanation for, with the DFT, vector multiplication in one domain being equivalent to circular convolution of the transforms of the vectors in the other domain? Since a DFT is just multiplication by a…
hotpaw2
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Does the number of samples matter for FFT, and how to get a specific frequency visible?

If I have a signal that has 740 samples, the sampling frequency is 1000 Hz, and I take an FFT of length 1024, are the frequencies I get now 0, fs/1024, 2*fs/1000, ..., 511*fs/1024? I mean, do I get this correctly: the frequency resolution does not…
aarggh
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Which sections to cover for my graduation thesis on blind source separation?

I'm not sure if I'm on right place to ask a simple suggestion, so please be kind and don't downvote my question. I'm not asking someone to do it for me, I just need short guidance how should I proceed. Currently, I'm writing a study of Blind source…
Regs
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Implementing a Matlab filter to cancel cross talk between two sensors

I have two sensors that have a cross talk between them. I would like to cancel the cross talk. For this I recorded two tracks, where sensor no.1 (called x1) has some input, and sensor no.2 (called x2) is zero. I was told to make the following…
user1017064
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Interview Questions for a DSP Engineer

I am preparing an interview which may require some knowledges on DSP. Is there any questions, fundamental concepts, and theories that I would not want miss? Thanks a lot for the suggestions.
user297850
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Mahalanobis vs Normalization+Euclidean

I'm using a set of features extracted from a signal for classifying the data window with KNN algorithm. Since the features have different value ranges, their influence on distance calculation is different when you use euclidean distance in KNN. To…
mostar
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