Noise Definition and 503 Threads

I'm using a portable rail gun in my novel - details in the paragraph below - but I wondered whether it would be as quiet as I'm suggesting. The slugs are coming out at Mach 5, which is a touch under 6,200 kmh. Obviously, they're breaking the sound barrier in the barrel, so would a tiny (or big)...

Hi all I would like to know how to suppress the spectrum of Poisson noise. At first, I tried "binning". I made the data of Poisson noise which sums up 4Hz sin wave.(the data number##N=10000##,and the data time is 1s) and I average out the data every 100bins. After this, I derived the power...

Dear all. I have made the power spectrum of Poisson noise(expected value ##λ=2##), and it becomes like this I think this is not good. I don't know why the power is so high when Random variable(x axis) is 0. I tried another expected value version ,but the result didn't change. so I would like to...

So this is a problem from the legendary Razavi book "Design of Analog CMOS Integrated Circuits" (Specifically, it is the problem 7.7 (c)). I got the solutions online but when I try to calculate the noise expression myself, I don't arrive at the same result. Lambda is assumed zero for neglecting...

Hi, I am working on a kalman filter where my measurement equation involves "-g + v" , where g is in m/s^2 and v is velocity random walk given in m/s/sqrt(hr). Feels like a stupid question, but how can I transform the unit of velocity random walk so I can do the calculation correctly?

I have long found myself turning my head fairly quickly when a noise steps on something I'm trying to hear. Sometimes it is just a noise like a bang or a pop that steps on a conversation I'm listening to, and sometimes it will happen when another person starts to speak and interferes with a...

I've my small incursion team entering a 10 foot diameter water outlet pipe using electric sleds for propulsion and was wondering about sensors in the pipe detecting them. They're wearing suits that mask their IR, but what about noise? The pipe flow is 3.18086e+07 l/h with a 1.25 m/s current...

So, my wife and I really like our new house, but after living in it for two months we desire to find a smart way to deaden the noise. You see, our previous house was smaller, had carpet mostly, and did not reflect the noise inside near as much as this new house. Our new house is larger, has...

My setup: I have the an LED (LED370E) in front of a photodiode (S12915-16R). The photodiode is connected to an ADC (DT5751) which has a counting functionality. The way it works is that it counts how many times the signal goes above a certain threshold and makes a histogram out of it. I know...

Suppose I have Gaussian white noise, with the usual dirac-delta autocorrelation function, <F1(t1)F2(t2)> = s2*d(t1-t2)*D12 Where s is the standard deviation of the Gaussian, little d is the delta function, and big D is the kronecker delta. For concreteness and to keep track of units, say F...

I have picked up a used pfeiffer turbomolecular pump and controller for pretty cheap. It runs like a champ, completely smooth and quiet except for when it’s first starting up. As it approaches 5500 rpm, it starts vibrating somewhat and sometimes produces a momentary scraping noise when the...

Hello:) I am working on my new 3d printer and i came across an interesting situation. According to the manufacture, my stepper motors need to have a voltage of roughly 0.95 volts. I checked mine and they were 0.81 volts, hence the not so smooth prints. Ok, so i increased the voltage to the...

I've been told that the 1/f noise for DC voltmeters is a problem when they measure a very low voltage (i.e. around 1 nV). Some readings can take weeks or even months. However, a DC voltmeter would have no problem to return a stable reading of a simple resistive circuit, of the order of the volt...

**Reposting this again, as I was asked to post this on a homework forum** 1. Homework Statement Hi, I am trying to solve this math equation (that I found on a paper) on finding the variance of a noise after passing through an LTI system whose impulse response is h(t) X(t) is the input noise...

Hi, I am trying to solve this math equation on finding the variance of a noise after passing through a system whose impulse response is h(t) X is the input noise of the system and Y is the output noise after system h(t) if let's say variance of noise Y is σy2=∫∫Rxx(u,v)h(u)h(v)dudv where...

--> Hi, I am reading about the capacitors. I have read that the capacitors block DC and behaves as open circuit in DC while short circuit in AC. The reason behind this is the charging and discharging of the capacitor. What is my perception about it, I will mention about it. " During the DC...

Hi everyone While learning about quantum mechanics, I became curious about the real-life experimental data. Wikipedia says that entanglement experiments require coincidence counters, because the majority of the signal received by detectors is noise. It further says, that coincidence counters...

Hi all. So is anyone having any luck with sw. power PCB mount supply modules for mixed signal? I have been experimenting with little DC-DC +5, +-15 and the TDK-Lambda AC/+5/+-15 power module. I have a mixed signal design that has a small size and low weight factor in my design. I have about...

Hi, For a machine I am designing, the linear actuator would ideally not produce much noise as it is intended to be in a relatively quiet environment. Just wondering do all actuators produce a large amount of noise pollution (it would need to produce a force of up to 125kg so it is not a small...

If we define Q factor as 2*pi* energy stored/ energy dissipated per cycle, what's the physical insight behind obtaining low phase noise for oscillators when we have high Q factors? (I know the mathematical derivation based on finding the frequency profile of an oscillator (like LC oscillator)...

Homework Statement Although it's easy to find calculations of thermal noise for resistors and capacitors, the equivalent for inductors is not found. What is the relevant formula? Is there some simple conversion for this? Homework EquationsThe Attempt at a Solution

Hi, I have a roughly 1.1 GHz signal to be downconverted to 100 MHz by mixing it with a 1 GHz local oscillator. I am not sure how to choose the performance of the LO. In particular: let's assume the LO has a jitter of 100 fs rms. At 1 GHz this corresponds to a frequency error of 100 kHz. Does...

I am currently working on a high power class E amplifier which will sit inside a metal enclosure. It is powered by two power supplies - both are isolated but one of the power supplies is mounted in the same enclosure. The power supply itself is in a metal case and that case is connected to...

Hi, I designed a small wireless sensor that can run from 5V USB power. I use a USB hub to power my device via a USB cable. There is so much noise on the 5V USB line that my device readings turn inaccurate. Using the oscilloscope I can see noise frequencies of 10MHz and down to 100kHz, assuming...

Hello everyone! It seems to me that there are many ways of calculating SNR depending on the type of signal and the nature of problems. I was able to get a decent amount of information for electrical signals but couldn't find resources which discuss the topic in a more generalized manner. I was...

Hello, I have a problem with the rotary lobe pump, it causes a very loud noise when running. The pump specs are as follows: Liquid: Syrup (The liquid is in the 15,000 liters tank.) Viscosity: 2200 cPs Temp: Ambient Flowrate: 15 m3/hr Discharge pressure: less than 2 bar (open ended pipe) Inlet...

I am using the "knife-edge" technique to find the intensity profile of a rectangular laser beam. The data that is obtained using this method is power, the integral of intensity. Therefore, to get the intensity profile we must differentiate the data. So, as expected, my data looks like a ramp...

For an optical telescope, light pollution is a problem and that's why put ground-based telescopes in remote places where there isn't much light. However, aren't we bombarded by radio waves from satellites for our phones and TVs? How do radio telescopes remove those?

Hi all, I performed a resonance experiment over the past two weeks, in which I collected the intensity of a Fabry-Perot cavity whilst adjusting the mirror distance with a piezo-element (the specific setup of the experiment is fairly detached from the question I will ask). My raw data is...

Hello, new poster, I am trying to do a fairly simple, but non-standard, environmental noise model run for a shooting range. The standard against which noise from the shooting range is to be compared is the Shot Noise Level (SNL). SNL is defined as the logarithmic average of the 25 highest...

Hello, I am working on the design of a flyback converter based on the LT3751 capacitor charging circuit. My design is similar to the 42 A cap charger example on pg. 25 of the LT3751 datasheet. In my case, the circuit runs on 12V and steps up the output to 430 V, but I am having some major noise...

What is the noise level at a high rise building if one was supposed to leave the window open in a balcony on the 80-th floor and above in an apartment on a skyscraper built in the city center of a large city like New York or Seoul, with all this car traffic underneath with their horns and sirens...

Hi, I'm hoping someone can point me in the right direction please. I'm using the Planck 2015 CMB temperature (intensity) SMICA pipeline maps (Nside = 2048) and am trying to determine the temperature variance of each individual pixel. Variance and hit-count were provided with the 2013 CMB maps...

To the best of my knowledge: a powerful oscillation at one frequency means more energy is required to make same medium oscillate at another frequency. Since sound perception works by detection of air oscillation, could a sufficiently powerful oscillation at an inaudible frequency (to humans)...

I'm currently working with the 1d DEEP2 DEIMOS fits files (see http://deep.ps.uci.edu/deep3/specprimer.html) and am trying to define some exclusion criteria in Python 2.7 for the data based on the noise. What's the best way to quantify the noise in order to do this? Thank you!

Hi, I recently have been trying to look into whether or not white noise works as a means to block out external sounds so i can concentrate. However, I want to know whether it actually impairs studying and reading. I do not care if it has no benefit, as long as it has no negative effects. I am...

Homework Statement As the title says, I'm trying to calculate the fundamental noise limit for an ideal photodetector, by specifically looking at the rate of incidence of annihilation of photons (and subsequent excitation of conducting electrons) on the detection surface. Since I'm looking for...

Hi all, Teacher here looking for some guidance. I'm teaching a class that I took myself a few years back, and I'm looking at my solution to a problem but I have a random value in my answer (which I know to be correct) but I can't for the life of me remember where this value came from! Can anyone...

Hello guys, I am currently having an annoying issue with my Mini Cooper (1.5-liter 3-cylinder TwinPower Turbo). When I leave it idling, above all when the air conditioning on, I can spot a strong fluttering noise clearly audible from the tailpipe. It could be described as an impulsive noise...

Homework Statement Suppose we have a noisy signal (superposition of many frequencies), but we are only concerned with a particular part of the signal within the noise at a frequency f(desired) = 1 GHz. In a sentence or two, explain how you could isolate the desired part of the signal by using...

These are the links to the specific product I am looking at and its noise characteristic graph. http://www.emelectronics.co.uk/a20.html http://www.emelectronics.co.uk/graphs/a20graph.htm I understand the graph for the most part, but I am confused about which one of the four filters that are...

If w[n] are samples of the white gaussian noise process, I know that E[w[n1] w[n2]] = 0 for a WGN process. what would the following expression lead to: E[w[n1] w*[n2]] = ? Would it also be zero? Thanks a lot!

Suppose you have two samples of white noise of equal amplitude. If you add them together ((sub)sample-by-(sub)sample that is), do you get one sample of white noise with twice the amplitude? How about pink noise?

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown > I am measuring EC of solution . I got Vec is 0.98V . After that, I took it to summing amplifier to reduce error from measurement . However, I saw a problem is that Vout of summing amplifier was...

Back in... man... probably 1996 I went to work with a thermal tumbler filled with some hot beverage or another. I settled in and took a swig; the liquid was good and hot and I kind of marveled at how well the tumbler worked and how it was nice to have a warm drink in my cool environment and...

Roger Penrose, July 2017. Correlated "noise" in LIGO gravitational wave signals: an implication of Conformal Cyclic Cosmology

Hi, I was looking for a second opinion on this article regarding LIGO's gravity waves and if it made sense or not. https://www.forbes.com/sites/startswithabang/2017/06/16/was-it-all-just-noise-independent-analysis-casts-doubt-on-ligos-detections "Analysis of the data attributed the signal to...

recently my neighbors and I have been awakened by a loud noise that sounds like something is being released under high pressure. An intense vibrating sound that lasts 30-45 seconds. We live across the steet from a soda manufacturer and down the road from a natural Gas transfer station. Both are...

I have a signal that I am able to calculate through an acoustic model for airfoil noise. I am told that the model solves for a narrowband frequency response, however, my measurement data is provided in third-octave band representation. How do I convert my current dataset to the third octave...

Hi, I am measuring an analog voltage with an Arduino analog in. The analog voltage comes from a cable which also contains digital signal wires. Do I need to separate the analog and digital signals using separate cables? If so, does the analog voltage signal cable need shielding? And if so, how...