Difference: 20151124MSciPhotometryAnalysisOb1part2 (1 vs. 6)

Revision 624 Nov 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"

Improvements

  • Following on from last weeks meeting, it was suggested the colourmaps used were not overly clear.
Line: 31 to 31
 
  1. We had the x and y coordinates of all the pixels of each star.
  2. We summed all x and all y for each star and then divided the sums by the amount of x and y coordinates we had.
  3. This we used as our centers.
Added:
>
>

Better background determination

  • Split each image into 4 quadrants such that:
l1_quadrants_copy.png

l2_copy.png

  • Found the following modes:
Location 1:
Filter Exposure Time (s) Mode in Quadrant 1 (photoelectrons $\rm{s}^{-1}$) Mode in Quadrant 2 (photoelectrons $\rm{s}^{-1}$) Mode in Quadrant 3 (photoelectrons $\rm{s}^{-1}$) Mode in Quadrant 4 (photoelectrons $\rm{s}^{-1}$)
Focus 10 47.32 46.84 47.80 46.84
Focus 10 47.08 46.37 47.56 46.61
Focus 10 46.61 45.65 46.84 45.89
Focus 10 47.56 47.08 48.28 47.08
Focus 10 47.80 47.32 48.52 47.56
Focus 10 47.56 46.84 48.04 47.08
Focus 10 48.52 47.56 49.00 48.04
Focus 10 47.56 46.61 47.80 46.61
Focus 10 47.80 46.84 48.28 47.08
Focus 10 48.04 47.32 48.76 47.56
Blue 90 5.31 5.20 5.36 5.26
Blue 90 5.39 5.28 5.44 5.31
Blue 90 5.34 5.20 5.36 5.26
Green 40 12.85 12.61 12.97 12.68
Green 40 12.97 12.67 13.03 12.73
Green 40 12.61 12.31 12.67 12.43
Red 40 14.10 13.86 14.16 13.86
Red 40 14.04 13.80 14.04 13.86
Red 40 13.92 13.68 13.98 13.80

Location 2:

Filter Exposure Time (s) Mode in Quadrant 1 (photoelectrons $\rm{s}^{-1}$) Mode in Quadrant 2 (photoelectrons $\rm{s}^{-1}$) Mode in Quadrant 3 (photoelectrons $\rm{s}^{-1}$) Mode in Quadrant 4 (photoelectrons $\rm{s}^{-1}$)
Focus 60 24.54 24.06 24.74 24.18
Focus 60 23.46 22.86 23.58 23.10
Focus 60 22.98 22.47 23.14 22.78
Green 120 7.19 7.03 7.27 7.11
Green 120 7.13 6.91 7.15 6.99
Green 120 7.03 6.83 7.09 6.93
Red 120 8.40 8.25 8.46 8.31
Red 120 8.37 8.21 8.38 8.25
Red 120 7.97 7.75 8.01 7.85
 -- DavidHadden - 24 Nov 2015
Added:
>
>
24.537334
 
META FILEATTACHMENT attachment="comparison_minus_dark.png" attr="" comment="" date="1448365511" name="comparison_minus_dark.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\comparison_minus_dark.png" size="804601" user="zxap012" version="1"
META FILEATTACHMENT attachment="alpha_persei_2_visual_newcmap.png" attr="" comment="" date="1448365531" name="alpha_persei_2_visual_newcmap.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_2\alpha_persei_2_visual_newcmap.png" size="1157104" user="zxap012" version="1"
Line: 46 to 87
 
META FILEATTACHMENT attachment="zoom_600_pe.png" attr="" comment="" date="1448377427" name="zoom_600_pe.png" path="zoom_600_pe.png" size="35946" user="zxap014" version="1"
META FILEATTACHMENT attachment="alpha_persei_visual_colour_map_comparison.png" attr="" comment="" date="1448378157" name="alpha_persei_visual_colour_map_comparison.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\alpha_persei_visual_colour_map_comparison.png" size="816994" user="zxap012" version="1"
META FILEATTACHMENT attachment="interpolation_comparison.png" attr="" comment="" date="1448378566" name="interpolation_comparison.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\interpolation_comparison.png" size="190520" user="zxap012" version="1"
Added:
>
>
META FILEATTACHMENT attachment="l1_quadrants_copy.png" attr="" comment="" date="1448394476" name="l1_quadrants_copy.png" path="l1_quadrants copy.png" size="993054" user="zxap014" version="1"
META FILEATTACHMENT attachment="l2_copy.png" attr="" comment="" date="1448394487" name="l2_copy.png" path="l2 copy.png" size="886891" user="zxap014" version="1"
META FILEATTACHMENT attachment="latexd72944025378454b75dac1c2793b1ae7.png" attr="h" comment="" date="1448395496" name="latexd72944025378454b75dac1c2793b1ae7.png" user="zxap014" version="1"

Revision 524 Nov 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"

Improvements

  • Following on from last weeks meeting, it was suggested the colourmaps used were not overly clear.
  • A version with better contrast has been chosen, and an example is seen below, with the old version, for comparison purposes.
Changed:
<
<		 alpha_persei_visual_colour_map_comparison.png
>
>		alpha_persei_visual_colour_map_comparison.png
 
  • Next the issue of over anti-aliased pixels in imshow was addressed.
  • Using the interpolation = 'nearest' option, future imshow images should display proper pixels, as seen below.
Changed:
<
<		interpolation_comparison.png
>
>		interpolation_comparison.png
 

Accounting for Dark Frames

  • In order to accurately analyse the stars, the background caused by the camera needs to be removed.

Revision 424 Nov 2015 - DavidHadden

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"

Improvements

  • Following on from last weeks meeting, it was suggested the colourmaps used were not overly clear.
Changed:
<
<
  • A version with better contrast has been chosen, and an example is seen below, with the old version, for comparison purposesalpha_persei_2_visual.pngalpha_persei_2_visual_newcmap.png
>
>
  • A version with better contrast has been chosen, and an example is seen below, with the old version, for comparison purposes.

alpha_persei_visual_colour_map_comparison.png

  • Next the issue of over anti-aliased pixels in imshow was addressed.
  • Using the interpolation = 'nearest' option, future imshow images should display proper pixels, as seen below.
interpolation_comparison.png
 

Accounting for Dark Frames

  • In order to accurately analyse the stars, the background caused by the camera needs to be removed.
  • To do this, a dark frame was scaled down and taken away from the image seen above.
Line: 40 to 45
 
META FILEATTACHMENT attachment="found_stars_1000_pe.png" attr="" comment="" date="1448377416" name="found_stars_1000_pe.png" path="found_stars_1000_pe.png" size="36849" user="zxap014" version="1"
META FILEATTACHMENT attachment="super_zoom_600_pe.png" attr="" comment="" date="1448377422" name="super_zoom_600_pe.png" path="super_zoom_600_pe.png" size="35268" user="zxap014" version="1"
META FILEATTACHMENT attachment="zoom_600_pe.png" attr="" comment="" date="1448377427" name="zoom_600_pe.png" path="zoom_600_pe.png" size="35946" user="zxap014" version="1"
Added:
>
>
META FILEATTACHMENT attachment="alpha_persei_visual_colour_map_comparison.png" attr="" comment="" date="1448378157" name="alpha_persei_visual_colour_map_comparison.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\alpha_persei_visual_colour_map_comparison.png" size="816994" user="zxap012" version="1"
META FILEATTACHMENT attachment="interpolation_comparison.png" attr="" comment="" date="1448378566" name="interpolation_comparison.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\interpolation_comparison.png" size="190520" user="zxap012" version="1"

Revision 324 Nov 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"

Improvements

  • Following on from last weeks meeting, it was suggested the colourmaps used were not overly clear.
Changed:
<
<
  • A version with better contrast has been chosen, and an example is seen below, with the old version, for comparison purposesalpha_persei_2_visual.pngalpha_persei_2_visual_newcmap.png
>
>
  • A version with better contrast has been chosen, and an example is seen below, with the old version, for comparison purposesalpha_persei_2_visual.pngalpha_persei_2_visual_newcmap.png
 

Accounting for Dark Frames

  • In order to accurately analyse the stars, the background caused by the camera needs to be removed.
  • To do this, a dark frame was scaled down and taken away from the image seen above.
  • An improved image can be seen below, with much of the noisy background regions reduced considerably.
Changed:
<
<		comparison_minus_dark.png
>
>		comparison_minus_dark.png

New algorithm for finding stars

  • Used algorithm as showed here.
  • We impleted some arbitrary threshold.
  • We set signal to 1 and background to 0.
  • We impleted the algorithm and unfortunately it has a similar problem to the previous algorithm.
found_stars_600_pe.png
 
Added:
>
>		zoom_600_pe.png

super_zoom_600_pe.png

  • It thinks that points not touching diagonally are stars.
  • At the threshold of 1000 photoelectrons we have the following:

found_stars_1000_pe.png

  • We implented a crude to find the centers of each star. We only need it as an initial parameter that we will feed to our Gaussian to estimate a much better center position.
  • We found the centers in the following way:
  1. We had the x and y coordinates of all the pixels of each star.
  2. We summed all x and all y for each star and then divided the sums by the amount of x and y coordinates we had.
  3. This we used as our centers.
 -- DavidHadden - 24 Nov 2015

META FILEATTACHMENT attachment="comparison_minus_dark.png" attr="" comment="" date="1448365511" name="comparison_minus_dark.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\comparison_minus_dark.png" size="804601" user="zxap012" version="1"
META FILEATTACHMENT attachment="alpha_persei_2_visual_newcmap.png" attr="" comment="" date="1448365531" name="alpha_persei_2_visual_newcmap.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_2\alpha_persei_2_visual_newcmap.png" size="1157104" user="zxap012" version="1"
META FILEATTACHMENT attachment="alpha_persei_2_visual.png" attr="" comment="" date="1448375772" name="alpha_persei_2_visual.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_2\alpha_persei_2_visual.png" size="701204" user="zxap012" version="1"
Added:
>
>
META FILEATTACHMENT attachment="found_stars_250.png" attr="" comment="" date="1448376581" name="found_stars_250.png" path="found_stars_250.png" size="55476" user="zxap014" version="1"
META FILEATTACHMENT attachment="zoom_250.png" attr="" comment="" date="1448376591" name="zoom_250.png" path="zoom_250.png" size="60123" user="zxap014" version="1"
META FILEATTACHMENT attachment="super_zoom_250.png" attr="" comment="" date="1448376600" name="super_zoom_250.png" path="super_zoom_250.png" size="54878" user="zxap014" version="1"
META FILEATTACHMENT attachment="found_stars_500.png" attr="" comment="" date="1448376606" name="found_stars_500.png" path="found_stars_500.png" size="35291" user="zxap014" version="1"
META FILEATTACHMENT attachment="found_stars_600_pe.png" attr="" comment="" date="1448377412" name="found_stars_600_pe.png" path="found_stars_600_pe.png" size="55056" user="zxap014" version="1"
META FILEATTACHMENT attachment="found_stars_1000_pe.png" attr="" comment="" date="1448377416" name="found_stars_1000_pe.png" path="found_stars_1000_pe.png" size="36849" user="zxap014" version="1"
META FILEATTACHMENT attachment="super_zoom_600_pe.png" attr="" comment="" date="1448377422" name="super_zoom_600_pe.png" path="super_zoom_600_pe.png" size="35268" user="zxap014" version="1"
META FILEATTACHMENT attachment="zoom_600_pe.png" attr="" comment="" date="1448377427" name="zoom_600_pe.png" path="zoom_600_pe.png" size="35946" user="zxap014" version="1"

Revision 224 Nov 2015 - DavidHadden

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Changed:
<
<

Corrections

>
>

Improvements

  • Following on from last weeks meeting, it was suggested the colourmaps used were not overly clear.
  • A version with better contrast has been chosen, and an example is seen below, with the old version, for comparison purposesalpha_persei_2_visual.pngalpha_persei_2_visual_newcmap.png

Accounting for Dark Frames

  • In order to accurately analyse the stars, the background caused by the camera needs to be removed.
  • To do this, a dark frame was scaled down and taken away from the image seen above.
  • An improved image can be seen below, with much of the noisy background regions reduced considerably.
comparison_minus_dark.png
  -- DavidHadden - 24 Nov 2015

META FILEATTACHMENT attachment="comparison_minus_dark.png" attr="" comment="" date="1448365511" name="comparison_minus_dark.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\comparison_minus_dark.png" size="804601" user="zxap012" version="1"
META FILEATTACHMENT attachment="alpha_persei_2_visual_newcmap.png" attr="" comment="" date="1448365531" name="alpha_persei_2_visual_newcmap.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_2\alpha_persei_2_visual_newcmap.png" size="1157104" user="zxap012" version="1"
Added:
>
>
META FILEATTACHMENT attachment="alpha_persei_2_visual.png" attr="" comment="" date="1448375772" name="alpha_persei_2_visual.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_2\alpha_persei_2_visual.png" size="701204" user="zxap012" version="1"

Revision 124 Nov 2015 - DavidHadden

Line: 1 to 1
Added:
>
>
META TOPICPARENT name="StewartBoogertPhotometry2015"

Corrections

-- DavidHadden - 24 Nov 2015

META FILEATTACHMENT attachment="comparison_minus_dark.png" attr="" comment="" date="1448365511" name="comparison_minus_dark.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_1\comparison_minus_dark.png" size="804601" user="zxap012" version="1"
META FILEATTACHMENT attachment="alpha_persei_2_visual_newcmap.png" attr="" comment="" date="1448365531" name="alpha_persei_2_visual_newcmap.png" path="Y:\Major Project\Figures\Alpha_Persei\Location_2\alpha_persei_2_visual_newcmap.png" size="1157104" user="zxap012" version="1"
View topic | History: r6 < r5 < r4 < r3 | More topic actions...
 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2021 by the contributing authors. All material on this collaboration platform is the property of the contributing authors.
Ideas, requests, problems regarding RHUL Physics Department TWiki? Send feedback