Difference: StewartBoogertPhotometry20171110 (1 vs. 3)

Revision 310 Nov 2017 - LunaMarieBorella1

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META TOPICPARENT name="StewartBoogertPhotometry2017"

Observation 1

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 A row of the above image gives the following

Background_of_Simulated_image.png

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Star Finder

Improved the star finder now out puts the number of stars allong with the coordinates of all the pixels in the stars

Tested on on of Beki's simulated images with no background

Screenshot_2017-11-10_01.15.50.png

It finds that there are 48 stars, there are 47 stars and the image has a white line on the right hand side which is abvoe threashold so it's counting that as the 48th star

I also found the backgroud for one of the real image using the 65X65 box but this took 40 mins to run so I didn't get a chance to plot it.

next step will be to do the aperture photometry and to optimize the background algorithm so it can be useful.

  -- BekiChafer - 09 Nov 2017
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META FILEATTACHMENT attachment="Average_background_of_Image_left_to_right_-_use_for_simulation.png" attr="" comment="" date="1510266796" name="Average_background_of_Image_left_to_right_-_use_for_simulation.png" path="Average background of Image left to right - use for simulation.png" size="29780" user="zavc984" version="1"
META FILEATTACHMENT attachment="TestbgLarge.png" attr="" comment="" date="1510266969" name="TestbgLarge.png" path="TestbgLarge.png" size="10128947" user="zavc984" version="1"
META FILEATTACHMENT attachment="Background_of_Simulated_image.png" attr="" comment="" date="1510267322" name="Background_of_Simulated_image.png" path="Background of Simulated image.png" size="33736" user="zavc984" version="1"
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META FILEATTACHMENT attachment="Screenshot_2017-11-10_01.15.50.png" attr="" comment="" date="1510276718" name="Screenshot_2017-11-10_01.15.50.png" path="Screenshot 2017-11-10 01.15.50.png" size="169713" user="zavc160" version="1"

Revision 209 Nov 2017 - RebekahChafer1

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META TOPICPARENT name="StewartBoogertPhotometry2017"
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Observation 1
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Observation 1

We took two images of the double cluster: NGC869, NGC884, with two different cameras, with different fields of view.

NarrowFieldView_4s_dc869.png widefield_15s_dc869.png

Star Simulation

Main aim this week: background fluctuations

From the larger image, you can see that there is a fluctuation in the background biased towards the left of the image.
Image below is the larger image with a high contrast:

BgBiasExample.png

To account for this bias, the image was analysed row by row. Taking a random row of the image and plotting the value with the column number, you get:

Fitting_Background_to_use_for_simulation.png

The majority of this is background, the spikes are stars. Then, I fit a 2d polynomial to the data. This was repeated for every row, and the parameters for the fit were averaged. This gave me the following function:

Average_background_of_Image_left_to_right_-_use_for_simulation.png

This was then used to add background fluctuations to images, poisson fluctuations also implemented.

TestbgLarge.png

A row of the above image gives the following

Background_of_Simulated_image.png

  -- BekiChafer - 09 Nov 2017

META FILEATTACHMENT attachment="NarrowFieldView_4s_dc869.png" attr="" comment="Narrow Field Image" date="1510236112" name="NarrowFieldView_4s_dc869.png" path="NarrowFieldView_4s_dc869.png" size="459403" user="zavc984" version="1"
META FILEATTACHMENT attachment="widefield_15s_dc869.png" attr="" comment="Wide Field Image" date="1510236151" name="widefield_15s_dc869.png" path="widefield_15s_dc869.png" size="14033318" user="zavc984" version="1"
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META FILEATTACHMENT attachment="BgBiasExample.png" attr="" comment="High Contrast Image to show bg bias" date="1510266300" name="BgBiasExample.png" path="BgBiasExample.png" size="7184467" user="zavc984" version="1"
META FILEATTACHMENT attachment="Fitting_Background_to_use_for_simulation.png" attr="" comment="" date="1510266602" name="Fitting_Background_to_use_for_simulation.png" path="Fitting Background to use for simulation.png" size="40193" user="zavc984" version="1"
META FILEATTACHMENT attachment="Average_background_of_Image_left_to_right_-_use_for_simulation.png" attr="" comment="" date="1510266796" name="Average_background_of_Image_left_to_right_-_use_for_simulation.png" path="Average background of Image left to right - use for simulation.png" size="29780" user="zavc984" version="1"
META FILEATTACHMENT attachment="TestbgLarge.png" attr="" comment="" date="1510266969" name="TestbgLarge.png" path="TestbgLarge.png" size="10128947" user="zavc984" version="1"
META FILEATTACHMENT attachment="Background_of_Simulated_image.png" attr="" comment="" date="1510267322" name="Background_of_Simulated_image.png" path="Background of Simulated image.png" size="33736" user="zavc984" version="1"

Revision 109 Nov 2017 - RebekahChafer1

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META TOPICPARENT name="StewartBoogertPhotometry2017"
Observation 1

-- BekiChafer - 09 Nov 2017

META FILEATTACHMENT attachment="NarrowFieldView_4s_dc869.png" attr="" comment="Narrow Field Image" date="1510236112" name="NarrowFieldView_4s_dc869.png" path="NarrowFieldView_4s_dc869.png" size="459403" user="zavc984" version="1"
META FILEATTACHMENT attachment="widefield_15s_dc869.png" attr="" comment="Wide Field Image" date="1510236151" name="widefield_15s_dc869.png" path="widefield_15s_dc869.png" size="14033318" user="zavc984" version="1"
 
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