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Entry  Sat Jun 19 17:31:46 2010, James K, Misc, Hartmann sensor, SURF Log -- Day 3, Initial Image Analysis 7x
    Reply  Tue Mar 1 10:47:18 2011, Aidan, Misc, Hartmann sensor, Electron to Counts conversion efficiency 
Message ID: 116     Entry time: Tue Mar 1 10:47:18 2011     In reply to: 53
Author: Aidan 
Type: Misc 
Category: Hartmann sensor 
Subject: Electron to Counts conversion efficiency 

Using some of the old data from James (attached below), I calculated the CCD conversion efficiency (CE) from electrons to bits (Counts).

Number of electrons(Ne) = QE*Number of Photons(Np)

noiseE = sqrt(Ne);

Number of Counts (NCo)= CE*Ne

Noise in Counts (noiseCo)= CE*sqrt(Ne)

noiseCo = sqrt(CE * NCo)

log(CE) = 2*noiseCo - NCo

Therefore CE = 10.0^(2*noiseCo - NCo)

From James's data on the intensity noise in the CCD, CE = 0.0269

 

Quote:
 
Using this function, I did the same analysis of the upper-left 200x200 pixels over all 200 images:

(data from 200 images, over the upper-left 200x200 pixels)

 

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