Difference: StewartBoogertPhotometry20171110 (1 vs. 2)

Revision 209 Nov 2017 - RebekahChafer1

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2017"
Changed:
<
<
Observation 1
>
>

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"
Added:
>
>
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

Line: 1 to 1
Added:
>
>
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"
 
This site is powered by the TWiki collaboration platform Powered by PerlCopyright © 2008-2022 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