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Questions tagged [measurement]

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12 views

UQI and VIF as image generation metrics

The aricle briefly describes various metrics for image generative models. It categorizes them into pixel-, feature-, task- and novelty-based metrics. Following such categorization I understand that A ...
• 173
29 views

Probabiliy density (Histogram) of measured data

The measured data from a gas sensor measurement system, in the absence of any excitation is as shown below. The data set consists of n = 65535 samples. The sensor output is discretized by the ...
1 vote
33 views

How to measure the vibration of an object on a video shot at high speed camera?

I have a video fragment which I split into frames (pictures). I use them in pairs (1 frame with 2, 2 with 3, etc.) to find shifts on x and y axes (i.e. how much I need to shift 1 frame to make it like ...
68 views

Correcting Drift and Stepped Pattern in Pressure Sensor Data

I’m observing drift and a stepped pattern in data from a piezoelectric pressure sensor measuring constant atmospheric pressure. the results are the following: The data should ideally be a flat line ...
61 views

Determine if measured gaussian noise have constant mean

lets say I am measuring ($z$) Gaussian noise with known variance sigma in each step, i.e. $z_k = v_k$, where $v_k$ is Gaussian distribution with known variance $\sigma_k$ (changing with each step) ...
39 views

Python - CV, contour and measurements

I have small problem with cv in Python and rhombus. I can read frame from the camera and create contours... ...
399 views

285 views

How to measure smoothness of a signal

Lets say I have two signals with a different number of data points - a step function and a smooth spline as you can see below. What is mathematical operation I can use to quantify the "smoothness&...
520 views

How to determine sampling rate of a lock-in amplifier?

I am trying to figure out the sampling rate of a lock-in amplifier and how it is related to the time constant. For example, imagine measuring sinusoidal waves at $1$, $5$, $10$, and $50$ Hz ...
125 views

Spectrum in real life with Spectrum in theory

as you know it is possible to measure the power spectral density ($|X(f)|^2$) of a certain voltage signal $x(t)$ through a Spectrum Analyzer. As far as I'm concerned, the simplest spectrum analyzer ...
• 334
55 views

Data smoothing in temperature measurements from MLX90614 BCC IR sensor

I am trying to measure temperature with the MLX90614 BCC IR sensor for my project, and I am having problems with my precision requirement. I had taken data for 1 second then took the mean of these ...
108 views

Extended Kalman Filter measurment vs input vector

What is difference between measurement and input vector in Extended Kalman Filter? Isn't always input also measurement? If so how to update input vector if I have acceleration or yawrate as input ...
450 views

Why is incoherence important for compressive sensing?

The literature on compressive sensing (CS) frequently notes that CS relies on two principles: sparsity and incoherence. While I understand why the signal of interest should be sparse in some domain ...
• 31
1 vote
208 views

Best window before FFT ? (for a signal consisting of 2 tones used for phase measurement)

I am doing phase measurments by transmitting and receiving tones (100 kHz and 16 kHz simultaneously). I am transmitting the tones and receiving them, applying Blackman Harris window and doing FFT for ...
• 135
127 views

Can I measure non-linearity of a line echo path?

I'm dealing with an echo signal from a hybrid. An echo path includes DAC, the hybrid, ADC and the line infrastructure. I can see, that after using a digital linear echo-canceller the residual echo ...
• 396
195 views

Why use complex envelope to model raw measurements?

The usual answers when asking "why use complex numbers to model measurements?" is usually: (a) Because you are measuring a phenomenon like electricity and magnetism. (b) Because it is super ...
• 123
176 views

Calculating the variance of vibration acceleration

In a vibration measurement of a rotating blade, I have the following information. The vibration signal is measured using a ICP accelerometer which has the following specification Measurement range: ...
47 views

Direct path and reflections of ultrasound transmission

I am using the following system: Ultrasonic chirp signals with central frequency 100kHz are being transmitted using ultrasonic sensor. After the transmission through the medium(air/solid/liquid/...
• 41
153 views

Oversample or undersample correlated noise?

I wish to measure nontrivial (non-Gaussian) broadband current noise for its distribution and power spectral density. The noise is amplified (with transimpedance amplifier) with some characteristic ...
• 101
88 views

How to determine number of observations based on measurement frequency?

So I'm working on a problem where I'm measuring a signal with two different instruments -- one is a low frequency measurement system (1 Hz), and the other is a high frequency measurement system (200 ...
• 183
321 views

Measuring THD using consumer sound card

I am trying to measure (estimate) THD of an audio path using a consumer sound card. The idea is that I do two measurements, one without the system being measured in the path and one with it: ...
• 55
1 vote
255 views

Proof that spectrum analyzer measures mathematical Power Spectral Density

It seems to me the power spectral density (PSD) is defined as follows. Consider a signal $X(t)$ The windowed version of this signal is Consider a signal $X(t)$. We defined a time-windowed version of \$...
• 312
46 views

how to get the location long and lat out of the raw measurements?

I'am making a research about GNSS I used GNSS logger to collect measurements but couldn't understand how these measurements turn into location of long and lat? the picture below of the measurements ...
45 views

Dirty Image Quality Assesment Measure

I was looking for a way to measure how dirty is the document in image processing. Example images below: a. Dirty Backgrounds b. Dirty Backgrounds with Text Can someone give me an initial idea to ...
• 127
1 vote
153 views

Phase difference measurement of a 100 kHz tone

I would like to measure the phase difference of a 100 kHz tone. The tone is transmitted and then received. The received tone is sampled using an 1 MHz 12 bit ADC(IQ) and the SNR is at least 35 dB. ...
• 135
1 vote
73 views

Can a Kalman Filter Be Applied Using Measurement-Space Dependent Sensors?

I'm currently attempting to apply a Kalman filter to track the angular position, velocity, and acceleration of a bike wheel, and I'm having a lot of trouble, so I want to check if I'm even applying ...
• 111
773 views

Adding Poisson noise to a time series signal

I'm working on a radiation detection problem. I have simulated some measurement count data and want to add an amount of Poisson background noise to achieve a certain SNR. Radiation count measurement (...
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