Difference: 20151310_MSciPhotometryLab (1 vs. 10)

Revision 1020 Oct 2015 - DavidHadden

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Histogram of the trial image
Line: 35 to 35
  Attached is a HR diagram for the Beehive Cluster. It was generated using the SIMBAD catalogue. The stars were found within 1.7 degrees of RA= 8h 40.1m, Dec= +19 59'.
Changed:
<
<
hr_beehive.png
>
>
hr_beehive.png
 
Using SIMBAD
  1. There are various ways to find a target using SIMBAD. Easiest is finding the target using its RA and DEC. To do this choose the 'Coordinate Query'.
  2. Type in your coordinates and define the radius of the region around your target that you want to explore.
Line: 53 to 53
 
META FILEATTACHMENT attachment="good_gaussian_fit.png" attr="" comment="A gaussian fit to some sample data." date="1444750168" name="good_gaussian_fit.png" path="good_gaussian_fit.png" size="171757" user="zxap014" version="1"
META FILEATTACHMENT attachment="gaussian_fit_unsaturated.png" attr="" comment="A Gaussian fit to an unsaturated star in the trial image." date="1444750494" name="gaussian_fit_unsaturated.png" path="gaussian_fit_unsaturated.png" size="195033" user="zxap014" version="1"
META FILEATTACHMENT attachment="hr_beehive.png" attr="" comment="HRdiagram for the beehive cluster using SIMBAD data." date="1444762922" name="hr_beehive.png" path="hr_beehive.png" size="86479" user="zxap014" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="TrialImage.png" attr="" comment="" date="1445352642" name="TrialImage.png" path="E:\Major Project\Images\TrialImage.png" size="49884" user="zxap012" version="1"
META FILEATTACHMENT attachment="TrialImageCrop.png" attr="" comment="" date="1445352650" name="TrialImageCrop.png" path="E:\Major Project\Images\TrialImageCrop.png" size="63221" user="zxap012" version="1"
>
>
META FILEATTACHMENT attachment="TrialImage.png" attr="" comment="Supplied trial image" date="1445352642" name="TrialImage.png" path="E:\Major Project\Images\TrialImage.png" size="49884" user="zxap012" version="1"
META FILEATTACHMENT attachment="TrialImageCrop.png" attr="" comment="Cropped version of supplied trial image showing two brightest stars" date="1445352650" name="TrialImageCrop.png" path="E:\Major Project\Images\TrialImageCrop.png" size="63221" user="zxap012" version="1"

Revision 920 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Histogram of the trial image
Added:
>
>
The trial images is shown below.

TrialImage.png

 The histogram is done over the entire trial image and is divided into 50 bins. The bin with the most entries represents the background. The rest of the bins are populated by stars.

histogram_fifty_bins.png

3D plots and Gaussian fits
Added:
>
>
Two selected stars from the trial image are shown below.

TrialImageCrop.png

 Attached images show the 3D plots of selected stars from the trial image (orange colouring). Gaussian fits (blue colouring) to selected stars are also attached. Unfortunately, the fits are not good. Although one of the stars is close to saturation and therefore the badness of its fit could be due to that, another star that is not saturated is badly fit as well.

star.png

Revision 820 Oct 2015 - DavidHadden

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Histogram of the trial image
Line: 45 to 45
 
META FILEATTACHMENT attachment="good_gaussian_fit.png" attr="" comment="A gaussian fit to some sample data." date="1444750168" name="good_gaussian_fit.png" path="good_gaussian_fit.png" size="171757" user="zxap014" version="1"
META FILEATTACHMENT attachment="gaussian_fit_unsaturated.png" attr="" comment="A Gaussian fit to an unsaturated star in the trial image." date="1444750494" name="gaussian_fit_unsaturated.png" path="gaussian_fit_unsaturated.png" size="195033" user="zxap014" version="1"
META FILEATTACHMENT attachment="hr_beehive.png" attr="" comment="HRdiagram for the beehive cluster using SIMBAD data." date="1444762922" name="hr_beehive.png" path="hr_beehive.png" size="86479" user="zxap014" version="1"
Added:
>
>
META FILEATTACHMENT attachment="TrialImage.png" attr="" comment="" date="1445352642" name="TrialImage.png" path="E:\Major Project\Images\TrialImage.png" size="49884" user="zxap012" version="1"
META FILEATTACHMENT attachment="TrialImageCrop.png" attr="" comment="" date="1445352650" name="TrialImageCrop.png" path="E:\Major Project\Images\TrialImageCrop.png" size="63221" user="zxap012" version="1"

Revision 717 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Histogram of the trial image
Line: 33 to 33
 
  1. Type in your coordinates and define the radius of the region around your target that you want to explore.
  2. 'Submit query' will give you all of the found targets in your selected region.
  3. To save the data you will have to go to 'Output Option' tab and choose the output format. This tab also allows you to choose the information you want to get about your targets.
Changed:
<
<
  1. I would recommend ASCII (aligned, without separator) type and only ticking the boxes of the data you need. This will make the data file less cluttered and easier to work with.
>
>
  1. I would recommend ASCII (aligned, without separator) type and only ticking the boxes of the data you need. This will make the data file less cluttered and easier to work with. Also, I would at first decrease the target radius thereby decreasing the amount of stars SIMBAD gives, making the data file even cleaner and easier to work with. I would write the code for that file first and then when that code is working perfectly, I would download all my target star data and run the complete data file through the code.
 -- ElenaCukanovaite - 13 Oct 2015

META FILEATTACHMENT attachment="histogram_fifty_bins.png" attr="" comment="Preliminary histogram of a trial image" date="1444732667" name="histogram_fifty_bins.png" path="histogram_fifty_bins.png" size="30394" user="zxap014" version="1"

Revision 614 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Histogram of the trial image
Line: 28 to 28
 Attached is a HR diagram for the Beehive Cluster. It was generated using the SIMBAD catalogue. The stars were found within 1.7 degrees of RA= 8h 40.1m, Dec= +19 59'.

hr_beehive.png

Changed:
<
<
>
>
Using SIMBAD
  1. There are various ways to find a target using SIMBAD. Easiest is finding the target using its RA and DEC. To do this choose the 'Coordinate Query'.
  2. Type in your coordinates and define the radius of the region around your target that you want to explore.
  3. 'Submit query' will give you all of the found targets in your selected region.
  4. To save the data you will have to go to 'Output Option' tab and choose the output format. This tab also allows you to choose the information you want to get about your targets.
  5. I would recommend ASCII (aligned, without separator) type and only ticking the boxes of the data you need. This will make the data file less cluttered and easier to work with.
 -- ElenaCukanovaite - 13 Oct 2015

META FILEATTACHMENT attachment="histogram_fifty_bins.png" attr="" comment="Preliminary histogram of a trial image" date="1444732667" name="histogram_fifty_bins.png" path="histogram_fifty_bins.png" size="30394" user="zxap014" version="1"

Revision 514 Oct 2015 - DavidHadden

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Histogram of the trial image

The histogram is done over the entire trial image and is divided into 50 bins. The bin with the most entries represents the background. The rest of the bins are populated by stars.

Added:
>
>
histogram_fifty_bins.png
 
3D plots and Gaussian fits

Attached images show the 3D plots of selected stars from the trial image (orange colouring). Gaussian fits (blue colouring) to selected stars are also attached. Unfortunately, the fits are not good. Although one of the stars is close to saturation and therefore the badness of its fit could be due to that, another star that is not saturated is badly fit as well.

Added:
>
>
star.png

stars.png

gaussian_fit.png

gaussian_fit_unsaturated.png

 
Detection of stars in a given image

Attached are cropped images of the trial image with the background signal removed. First the mode of the image is found, then its standard deviation. The background is then defined as any value that falls within x*the standard deviation of the mode. The two images attached show instances for x=3 and x=15. This can be thought of as the detection threshold.

Added:
>
>
three_sts.png

fifteen_std.png

 
HR diagram of the Beehive Cluster

Attached is a HR diagram for the Beehive Cluster. It was generated using the SIMBAD catalogue. The stars were found within 1.7 degrees of RA= 8h 40.1m, Dec= +19 59'.

Added:
>
>
hr_beehive.png
 -- ElenaCukanovaite - 13 Oct 2015

META FILEATTACHMENT attachment="histogram_fifty_bins.png" attr="" comment="Preliminary histogram of a trial image" date="1444732667" name="histogram_fifty_bins.png" path="histogram_fifty_bins.png" size="30394" user="zxap014" version="1"

Revision 413 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
Added:
>
>
Histogram of the trial image

The histogram is done over the entire trial image and is divided into 50 bins. The bin with the most entries represents the background. The rest of the bins are populated by stars.

3D plots and Gaussian fits

Attached images show the 3D plots of selected stars from the trial image (orange colouring). Gaussian fits (blue colouring) to selected stars are also attached. Unfortunately, the fits are not good. Although one of the stars is close to saturation and therefore the badness of its fit could be due to that, another star that is not saturated is badly fit as well.

Detection of stars in a given image

Attached are cropped images of the trial image with the background signal removed. First the mode of the image is found, then its standard deviation. The background is then defined as any value that falls within x*the standard deviation of the mode. The two images attached show instances for x=3 and x=15. This can be thought of as the detection threshold.

HR diagram of the Beehive Cluster

Attached is a HR diagram for the Beehive Cluster. It was generated using the SIMBAD catalogue. The stars were found within 1.7 degrees of RA= 8h 40.1m, Dec= +19 59'.

 -- ElenaCukanovaite - 13 Oct 2015

META FILEATTACHMENT attachment="histogram_fifty_bins.png" attr="" comment="Preliminary histogram of a trial image" date="1444732667" name="histogram_fifty_bins.png" path="histogram_fifty_bins.png" size="30394" user="zxap014" version="1"

Revision 313 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
-- ElenaCukanovaite - 13 Oct 2015
Line: 7 to 7
 
META FILEATTACHMENT attachment="stars.png" attr="" comment="Two of the stars in the trial image" date="1444732803" name="stars.png" path="stars.png" size="186290" user="zxap014" version="1"
META FILEATTACHMENT attachment="three_sts.png" attr="" comment="Cropped part of the trial image. White space represents the background removed. The background is defined within 3 standard deviation of the mode value." date="1444732896" name="three_sts.png" path="three_sts.png" size="90359" user="zxap014" version="1"
META FILEATTACHMENT attachment="fifteen_std.png" attr="" comment="Cropped part of the trial image. White space represents the background removed. The background is defined within 15 standard deviation of the mode value." date="1444732942" name="fifteen_std.png" path="fifteen_std.png" size="48367" user="zxap014" version="1"
Deleted:
<
<
META FILEATTACHMENT attachment="1.py.txt" attr="" comment="Code used for generating the images on this page." date="1444733027" name="1.py.txt" path="1.py" size="3200" user="zxap014" version="1"
 
META FILEATTACHMENT attachment="gaussian_fit.png" attr="" comment="Gaussian fit to a saturated star in the trial image." date="1444750039" name="gaussian_fit.png" path="gaussian_fit.png" size="145445" user="zxap014" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="good_gaussian_fit.png" attr="" comment="A gaussian fit to EROS-2 data" date="1444750168" name="good_gaussian_fit.png" path="good_gaussian_fit.png" size="171757" user="zxap014" version="1"
>
>
META FILEATTACHMENT attachment="good_gaussian_fit.png" attr="" comment="A gaussian fit to some sample data." date="1444750168" name="good_gaussian_fit.png" path="good_gaussian_fit.png" size="171757" user="zxap014" version="1"
 
META FILEATTACHMENT attachment="gaussian_fit_unsaturated.png" attr="" comment="A Gaussian fit to an unsaturated star in the trial image." date="1444750494" name="gaussian_fit_unsaturated.png" path="gaussian_fit_unsaturated.png" size="195033" user="zxap014" version="1"
Added:
>
>
META FILEATTACHMENT attachment="hr_beehive.png" attr="" comment="HRdiagram for the beehive cluster using SIMBAD data." date="1444762922" name="hr_beehive.png" path="hr_beehive.png" size="86479" user="zxap014" version="1"

Revision 213 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
 
META TOPICPARENT name="StewartBoogertPhotometry2015"
-- ElenaCukanovaite - 13 Oct 2015
Line: 7 to 7
 
META FILEATTACHMENT attachment="stars.png" attr="" comment="Two of the stars in the trial image" date="1444732803" name="stars.png" path="stars.png" size="186290" user="zxap014" version="1"
META FILEATTACHMENT attachment="three_sts.png" attr="" comment="Cropped part of the trial image. White space represents the background removed. The background is defined within 3 standard deviation of the mode value." date="1444732896" name="three_sts.png" path="three_sts.png" size="90359" user="zxap014" version="1"
META FILEATTACHMENT attachment="fifteen_std.png" attr="" comment="Cropped part of the trial image. White space represents the background removed. The background is defined within 15 standard deviation of the mode value." date="1444732942" name="fifteen_std.png" path="fifteen_std.png" size="48367" user="zxap014" version="1"
Changed:
<
<
META FILEATTACHMENT attachment="1.py.txt" attr="" comment="" date="1444733027" name="1.py.txt" path="1.py" size="3200" user="zxap014" version="1"
>
>
META FILEATTACHMENT attachment="1.py.txt" attr="" comment="Code used for generating the images on this page." date="1444733027" name="1.py.txt" path="1.py" size="3200" user="zxap014" version="1"
META FILEATTACHMENT attachment="gaussian_fit.png" attr="" comment="Gaussian fit to a saturated star in the trial image." date="1444750039" name="gaussian_fit.png" path="gaussian_fit.png" size="145445" user="zxap014" version="1"
META FILEATTACHMENT attachment="good_gaussian_fit.png" attr="" comment="A gaussian fit to EROS-2 data" date="1444750168" name="good_gaussian_fit.png" path="good_gaussian_fit.png" size="171757" user="zxap014" version="1"
META FILEATTACHMENT attachment="gaussian_fit_unsaturated.png" attr="" comment="A Gaussian fit to an unsaturated star in the trial image." date="1444750494" name="gaussian_fit_unsaturated.png" path="gaussian_fit_unsaturated.png" size="195033" user="zxap014" version="1"

Revision 113 Oct 2015 - ElenaCukanovaite

Line: 1 to 1
Added:
>
>
META TOPICPARENT name="StewartBoogertPhotometry2015"
-- ElenaCukanovaite - 13 Oct 2015

META FILEATTACHMENT attachment="histogram_fifty_bins.png" attr="" comment="Preliminary histogram of a trial image" date="1444732667" name="histogram_fifty_bins.png" path="histogram_fifty_bins.png" size="30394" user="zxap014" version="1"
META FILEATTACHMENT attachment="star.png" attr="" comment="A star from the trial image" date="1444732759" name="star.png" path="star.png" size="297398" user="zxap014" version="1"
META FILEATTACHMENT attachment="stars.png" attr="" comment="Two of the stars in the trial image" date="1444732803" name="stars.png" path="stars.png" size="186290" user="zxap014" version="1"
META FILEATTACHMENT attachment="three_sts.png" attr="" comment="Cropped part of the trial image. White space represents the background removed. The background is defined within 3 standard deviation of the mode value." date="1444732896" name="three_sts.png" path="three_sts.png" size="90359" user="zxap014" version="1"
META FILEATTACHMENT attachment="fifteen_std.png" attr="" comment="Cropped part of the trial image. White space represents the background removed. The background is defined within 15 standard deviation of the mode value." date="1444732942" name="fifteen_std.png" path="fifteen_std.png" size="48367" user="zxap014" version="1"
META FILEATTACHMENT attachment="1.py.txt" attr="" comment="" date="1444733027" name="1.py.txt" path="1.py" size="3200" user="zxap014" version="1"
 
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