Adding and generation of poisson noise to a time varying signal
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Hi,
My questions is to do with addition of noise to a predefined signal.
Assume I have predefined a time_varying signal in array A. Now I like to add noise to this signal, I know that my noise follows a poisson process or is poisson in nature, I also know that my noise has a rms value of X.
I just like to know how I can generate and noise this type of noise.
Thanks, Arsalan.
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Image Analyst
on 5 Jan 2013
What are the values of your signal? Do you know that with values of more than about 10, Poisson noise is well approximated by Gaussian noise? See Wikipedia. So you might be able to use Gaussian noise. If you think that it has the shape of Poisson noise, but the values are a lot more than 10, then you could use log-normal noise.
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Image Analyst
on 6 Jan 2013
Well what about the poissrnd function that you said you were going to try (I don't have that)? And you may have a current that is some number of microamps, but an incoming photon gives just a pulse, doesn't it? It doesn't give a continuous stream of current. So you have to model that as a stochastic process. Sure it's a burst of current but it occurs in bursts and each burst is a stochastic event, so you can use rand() or poissrnd (I guess) for determining when the next pulse comes along. That would be a Poisson stochastic process. Now it's been almost 30 years since I took classes in detectors, reasons for their noise, and stochastic optical processes (from Eustace Dereniak, I'm sure you've heard of him), but I thought shot noise was an inherent characteristic of a sparse stream of photons, not something that you could add onto it. But you'd best ask your Professor.
More Answers (2)
Avi Silbiger
on 3 Dec 2014
I'm sure you already resolved the issue, but here is a short piece of code that simulates shot noise, for those who might need it in the future.
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