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1answer
20 views

Accurate measurement of object's position on a bayer-filtered and grayscaled images

This is an experience-related question about cameras and image processing. I have a laboratory setup. Under some simplifications it looks like a red ball rolling on a white table (the real setup is ...
0
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0answers
5 views

What is the technical description of 'sensitivity' in Lock-In amplifiers? [migrated]

While I understand that the sensitivity in Lock In amplifiers should be as close as possible to the range within which the signal to be measured lies, I could not find a more technical description of ...
0
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0answers
78 views

Get the distinctive deltas of quite noisy and very variable / dynamic measurement values

for my thesis I need to point out the distinctive deltas of my measurements for further use. The jumps can occur with different heights over different time slots. And the absolute base values can ...
0
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0answers
20 views

If a signal is added to another in the freq. domain, how to filter it out?

I have two signals, $x$ and $y$. I know that $F(x)=F(s)+F(n)$ and $F(y)=F(n)$, where $s$ is the 'clean' signal, $n$ is the added noise and $F$ donate Fourier Transform. To obtain the clean signal, I ...
5
votes
2answers
49 views

Finding filaments in high dimensional space

I have unit vectors in a high-dimensional space (~300) that are non-uniformly distributed over this hypersphere. There is physical meaning when the vectors are clustered together, but I'm ...
0
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0answers
12 views

Determine type of acceleration sensor fault

This is a segment of an acceleration meausurement of a single sensor of a Bridge Structural Health Monitoring System. It's obviously faulty, but what exactly is the cause for this behaviour?
2
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2answers
93 views

Measuring non-planar objects in image

I'm working on a computer vision application (using openCV) and the goal is to measure the width of an object before/after it falls on a container. So after the fall its position will be random, ...
0
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1answer
122 views

Digital low-pass filters; best practice application

I have time domain strain gauge data from a structure which is subjected to low frequency, random loading. The signal / noise ratio is pretty good, but I would like to try to improve on it as much as ...
1
vote
1answer
214 views

Why these harmonics always present?

I am using Audio Precision 2700 to test some test vectors. I have connected resistor banks as class - d power amp's load, and tap from this resistor using a XLR cable to the AP. When my power amp ...
1
vote
1answer
96 views

Measuring the similarity of two waveforms [closed]

I have two approximately sine truncated waveforms of different amplitudes and I want a numerical measure of how similar they are to each other. I am sending a sonic pulse train whose multiple ...
1
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0answers
38 views

Image objects dispersion and diversity measures

I have images like below: I want to find some measures describing black spots dispersion and diversity. First measures I use are mass center off all black spots, mean area of spot, stdev of area ...
0
votes
2answers
182 views

measure angle between two lines, can rotation center constraint be used to refine the initial measured result?

I'm trying to measure the angle between two needle positions in an analog meter (gauge). such as: After the image processing of several images, I get the processed image below(a image show different ...
0
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1answer
39 views

what is standard acoustic volume

In Audio Experts book, it's given as Sound pressure meters must be calibrated at factory to a standard acoustic volume. So what doth this ...
2
votes
1answer
77 views

Digital Vs. Analog Phase measurement [closed]

I'm working on a Ultrasonic Transducers resonance tracking system. Where phase shift between Voltage and Current is the feedback signal for my system when phase difference is Zero that means system is ...
3
votes
0answers
504 views

How to convert raw pulse sensor data into actual pulse?

I've built a simple device, which sends readings from a pulse sensor to a PC. I get these data: What technique or algorithm can I use in order to calculate the pulse rate (beats per minute) from ...
5
votes
1answer
195 views

Received Morse Code signal-to-noise ratio?

I have some digital recordings of some received over-the-air CW broadcasts of known plain-text (W1AW code practice) at known WPM code speeds, but in moderate to heavy RF noise and fading. Can I ...
4
votes
1answer
421 views

Compare image segmentation approaches

I've got a question related to a comparison of image segmentation algorithms. I'd like to compare two algorithm results to each other in step one. In another step I'd like to compare the two ...
1
vote
1answer
325 views

Accuracy of Goertzel algorithm for measure harmonic

If I use Goertzel algorithm for calculate the magnitude of current or voltage, use for measure current harmonic or voltage harmonic or fundamental component. I not use for detect harmonic. Do you know ...
9
votes
3answers
796 views

How to detect “fast” changes in signal processing

I'm working on a project where we measure the solderability of components. The measured signal is noisy. We need to process the signal in real time so that we are able to recognize the change that ...
10
votes
1answer
353 views

Kalman Filter - best way to handle “derived” measurements?

Ie, if you have as state variables position (p) and velocity (v), and I make low-frequency measurements of p, this also indirectly gives me information about v (since it's the derivative of p). What ...
12
votes
1answer
178 views

Deconvolving the measurement system from the system response

I'm preforming a system identification measurement, and would like to deconvolve the measurement system's response from the measured response. The set up of the system is as follows; the signal is ...
5
votes
2answers
217 views

How to measure the quality (or difference in quality) of different images?

I would like to measure the quality of a color image, possibly as a difference to another image, but if possible, on its own too. This question comes from the fact that we have a vision application, ...
16
votes
5answers
9k views

Determining the mean and standard deviation in real time

What would be the ideal way to find the mean and standard deviation of a signal for a real time application. I'd like to be able to trigger a controller when a signal was more than 3 standard ...