Fft Definition and 163 Threads

well, that's the heading of a project i am doing...i need some help on neutron detectors... how they are dectected and what is the probable graph of count rate vs, pulse height that i might get for a nuclar fission reaction of U-235... can anyone help?

Hello I have a Gaussian Pulse in the frequency domain and transform it with the IFFT into the time-domain. My Problem is now that I can't figure out a way to give the sample points the correct time-scale. What kind of formula do I need to use? Thank You for helping me!

Hi all, I am currently looking into the energy correction factor of the Hann window. So far I have found that to correct for the application of Hann-window and Fourier transform the result needs to be multiplied by sqrt(32)/sqrt(3). Can any of you explain how to get that factor ? The...

Homework Statement Hi, I hope someone could help me, I have been trying to solve this problem with FFT in matlab, why?, because my teacher gave it as homework. The problem is the following. Obtain the value of the following integer using FFT: Homework Equations the integer goes...

Hi, I hope someone could help me, I have been trying to solve this problem with FFT in matlab, why?, because my teacher gave it as homework. The problem is the following. Obtain the value of the following integer using FFT: the integer goes from [-infinte, infinite], and the function is...

Hello all. I am working on a problem for class that is taking some time data and changing it to frequency data. I am using excel and the fast Fourier transform(fft). I am having a problem graphing the results. I am very new to signal processing. I am only given the data which is 1024...

Hi! How can I time shift (ts) a real signal (N samples, T time period, dt sample rate, Fs sampling frequency) using matlab: Timeshift signal = ifft (fft(signal)*exp(2*i*pi*Fs*ts)) ? I am trying to do it this way and it is not working? For example how would you shift a Cos signal to...

What I want to do is apply a frequency-independent phase shift to a Gaussian Noise signal. Obviously I can just invert it to get a pi shift. Also I can take the Hilbert transform to get a pi/2 shift and I can invert that to give myself in effect a 3/2pi shift. BUT... what I want to do is to be...

Hi, I wasn't really sure whether to put this post under Physics or Engineering. I was just wondering whether someone can gimme some help or info or guidance... I am currently working on a project in which I am using the FFT (Fast Fourier transform) algorithm. In a nutshell, I am trying to use...

Does anyone know of any good texts that cover Discrete Fourier Analysis and the Fast Fourier Transform? *I don't know if this belongs here in the HW help or in General Math section.

I start with calculating psi(x,0). Then i use fft(psi(x,0)) to get the Fourier coefficients. and with fftshift i get the terms with negative index in the beginning. Then i multiply with the timedependent factor and use ifftshift and ifft to get the wavefunction psi(x,t). Here is the code...

This is part of my senior project. Please help! I'm trying to use a code to FFT a real, even set of data, but the results are not real and even as would be expected. The code I'm using is availabe http://www.koders.com/c++/fid1C48DD8DBB45CA4B87C9A38DAFC532E793443862.aspx (and...

Could somone possibly describe this http://home.bak.rr.com/berlin/088821368-guess1.jpg FFT. I need to know the properties and frequency. Thanks for anyone's time who helps. (BTW, if this is in the wrong forum, I could use some redirection).