-- AnishaVadher - 14 Oct 2016
  • Working out how much background for each pixel
  • Plotted a histogram of number of photoelectrons against the frequency for a 0.1s exposure in the dark frame which follows a Gaussian distribution
  • Histogram_of_number_of_photoelectrons_for_0.1s_exposure.png
  • Number of photoelectrons = pixel value (ADU) * Gain
  • Gain = 2.3 e/ADU (value from PH2900 report)
  • From the histogram I will obtain the value at the peak and the error from the FWHM
  • Error in the peak = FWHM/2.35
  • I will get these statistics for each exposure time in the dark frames that I have taken and plot the peak value as a function of exposure time and the error as a function of exposure time.
  • There are big gaps between the bins which I am not sure why.
  • Edit - the gaps are due to the fact that the histogram only takes integer values so increasing the number of bins leads to more gaps in the histogram.
  • Histrogram of number of photoelectrons for a 0.1s exposure in the dark frame with 45 bins.:
    Histogram_of_number_of_photoelectrons_for_0.1s_exposure_45_bins.png

  • Also plotted a histogram for the sum of pixel along the x-axis values against frequency for a 0.1s exposure in the dark frame which follows a Poisson distribution
  • The histograms from the sum of pixels along the y-axis follows a Gaussian distribution.
Difference_between_summing_across_x-axis_and_y-axis.png

  • Plotted the median intensity of the pixels as a function of exposure time using the values given from the image using np.median in python. I am yet to work out the errors.

  • The median intensity as a function of exposure time.:
    The_median_intensity_as_a_function_of_exposure_time.png

  • Table of values obtained from Gaussian fit to dark frames

Exposure Fitted Mean Fitted Standard Deviation
0.10 917.12 6.41
0.20 916.76 6.42
0.50 916.65 6.42
001 917.73 6.43
002 916.64 6.44
005 917.73 6.47
010 919.34 6.48
020 920.08 6.51
030 920.96 6.55
040 922.16 6.58
050 922.69 6.60
060 922.48 6.62
090 925.88 6.71
200 933.75 6.99
300 939.33 7.22
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Topic revision: r2 - 27 Oct 2016 - AnishaVadher

 
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