Difference between revisions of "Manta G032 camera measurements"

From Course Wiki
Jump to: navigation, search
(Calculations)
Line 4: Line 4:
 
This page contains data from the demo I did in lecture on 9/22/2015 of the Manta G032 camera.
 
This page contains data from the demo I did in lecture on 9/22/2015 of the Manta G032 camera.
  
The point was to measure the gain, dark noise, and read noise of the Manta G032 cameras we use in lab.
+
The point was to measure the gain <math>g</math>, dark current <math>I_d</math>, and read noise <math>N_r</math> of the Manta G032 cameras we use in lab.
  
 
==Measurement procedure==
 
==Measurement procedure==
Line 10: Line 10:
 
* 100 frame movie recorded at 20 FPS with an exposure of 150 &mu;s.
 
* 100 frame movie recorded at 20 FPS with an exposure of 150 &mu;s.
 
* 100 frame dark movie recorded with identical settings.
 
* 100 frame dark movie recorded with identical settings.
 +
* Variance of each pixel (noise squared) plotted versus average value (signal).
  
 
==Calculations==
 
==Calculations==
Line 20: Line 21:
 
* and <math>D_{x,y}[t] is the number of dark current electrons generated during time interval <math>t</math>
 
* and <math>D_{x,y}[t] is the number of dark current electrons generated during time interval <math>t</math>
  
 +
Take the variance of the pixel value equation, which is equal to the noise squared.
 +
 +
:<math>\left\langle\left(P_{x,y}-\overline{P_{x,y}}=g\left(\langle I_{x,y}+N_r^2\right)\right)\right\rangle</math>
  
 
{{Template:20.309 bottom}}
 
{{Template:20.309 bottom}}

Revision as of 19:09, 22 September 2015

20.309: Biological Instrumentation and Measurement

ImageBar 774.jpg


Overview

This page contains data from the demo I did in lecture on 9/22/2015 of the Manta G032 camera.

The point was to measure the gain $ g $, dark current $ I_d $, and read noise $ N_r $ of the Manta G032 cameras we use in lab.

Measurement procedure

  • Light source directed at the camera so to produce a range of intensities
  • 100 frame movie recorded at 20 FPS with an exposure of 150 μs.
  • 100 frame dark movie recorded with identical settings.
  • Variance of each pixel (noise squared) plotted versus average value (signal).

Calculations

The expression for the value read from pixel $ x,y $ during time interval $ t $ is:

$ P_{x,y}[t]=g \left(I_{x,y}[t]+R_{x,y}[t]+D_{x,y}(t)) \right) $,

where

  • $ I_{x,y}[t] $ is the number of photoelectrons that are generated during interval $ t $,
  • $ R_{x,y}[t] $ is the read noise during time interval $ t $,
  • and $ D_{x,y}[t] is the number of dark current electrons generated during time interval <math>t $

Take the variance of the pixel value equation, which is equal to the noise squared.

$ \left\langle\left(P_{x,y}-\overline{P_{x,y}}=g\left(\langle I_{x,y}+N_r^2\right)\right)\right\rangle $