# Tagged Questions

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30 views

### SNR problem with different sampling rates using innerproduct

I'm trying to measure the amplitude of a sinusoidal component in a noisy signal. Since the signal frequency is known beforehand, I'm calculating scalar product with a sine and cosine base function ...
23 views

### Why is the term deconvolution used more for signals and not so much (or at all) for systems?

Wikipedia defines mathematical deconvolution here, and with the examples given and my experience, what I've read over the years is that deconvolution is used to determine an input signal provided a ...
38 views

### Measuring amplitude of a spectral component

I'm trying to measure the amplitude of a spectral component in a signal. The component's frequency is always known beforehand. I take a given number of samples, apply the flattop window to reduce ...
61 views

### Best reference for object size estimation in an image

I'm working on a project where I need to measure the size of a 2D object on a flat surface from an image. I have total freedom to create a reference with any shape and size. The camera I am using is ...
59 views

### Sampling and zero crossing

I am sampling a sine wave of 50Hz(stepped down from 230V) at the rate of 500KHz. For identifying disturbances in the wave, i was thinking of comparing a cycle of incoming sine values with reference ...
46 views

### White noise sound vs harmonic sound reverb

I use a microphone array to localise a sound source in a small lecture theatre. I tested it with white noise and a bird noise source. I found out that the white noise source give very good results. ...
12 views

### How is per-class rate defined?

I've recently read the following For our pixel labeling, consistent with [20], we report the number of pixels correctly classified (per-pixel rate) and the average of per-class rates. The per-...
30 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 ...
81 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 ...
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 ...
52 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 ...
210 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, ...
238 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 ...
244 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 ...
143 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 ...
44 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 ...
277 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 ...
41 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 ...
88 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 ...
718 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 ...
205 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 ...
483 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 ...
385 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 ...
1k 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 ...
449 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 ...
195 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 ...