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11 Image quality from the Firstcut and my run

  • Among the 2142 exposures Klaus put together, there are 1611 of them have the corresponding firstcut catalogs as of 12/28/2012. The corresponding files can be downloaded from the attachments
    • firstcut_image_quality_12282012.txt: exposures that have firstcut catalogs
    • expid_no_firstcut_cat.txt: exposure ids that do not have firstcut catalog available
    • Overall distribution of the R50, Whisker, Whisker rms from the firstcut catalog (all available exposures)
  • I choose 47 exposures from the list Klaus prepared and cross compare the properties we are interested in. These exposures has both large and small PSFs.

161500, 161501, 161502, 161503, 161508, 161509, 161510, 161511,
161512, 161515, 161516, 161517, 161518, 161519, 161520, 161521,
161522, 161523, 161524, 161525, 161527, 161528, 161529, 161530,
161531, 161533, 161534, 161535, 161536, 161537, 161538, 162511,
162512, 162513, 162514, 162517, 162518, 162519, 162520, 162521,
162524, 162525, 162526, 162527, 162528, 162529, 162530

The star selection I used are defined by the following:

rad = b.FLUX_RADIUS
mag = b.MAG_AUTO
flag = b.FLAGS
ok = (mag>=10.5)*(mag<=12)*(flag ==0)*(rad<5.)
radmedian = median(rad[ok])
StarIdx = (mag>=10.5)*(mag<=13)*(flag ==0)*(abs(rad-radmedian)<=0.2)

  • R50, Whisker Length and Whisker RMS (definitions refer to the doc by Gary)
    • the suffix "_sextractor" is from my run of sextractor on the images.
    • the one no suffix is from the weighted moments after subtracting the weights contribution
    • In all these measurement, I use non-windowed 2nd moments from sextractor run and firstcut catalog!
    • the red lines are 45 degree lines

  • Scaling between fwhm and r50:
    • based on all of firstcut catalog (not limited to the above exposures)
    • based on my run of sextractor:
  • Overall distribution of the R50, Whisker, Whisker rms from my weighted moments measurement for 147 exposures

  • What we expect from model: Here, I generate one PSF star at each CCD center from the optics model and then add circular seeing to them. There is no noise assumed.
    • Gaussian circular seeing
    • Moffat circular seeing (the R50 is measured by fitting Moffat profile)
    • Moffat circular seeing with sky noise (assume star magnitude = 16, exptime = 30 sec, r band des sky noise)

Attachments