WISE Simulated Images of a Mid-Latitude Field: WPHOT Photometry

Updated: June 24, 2009

• Non-pattern vs. Pattern Noise Performance

	W3	W4
WPRO vs. Truth, RMS

Updated: June 24, 2009

• Non-pattern noise photometry:
  /wise/fops/coadds/18/1802/decs/p006-nopat
  /wise/fops/coadds/18/1808/decs/p020-nopat
  /wise/fops/coadds/17/1797/decs/m006-nopat
  /wise/fops/coadds/17/1791/decs/m026-nopat
  

	W1	W2	W3	W4
WPRO vs. Truth, w/ RMS
WPRO mag sigmas
WAPPco vs. Truth, w/ RMS
WAPPco mag sigmas

Updated: June 24, 2009

• Pattern noise photometr:
  /wise/fops/coadds/18/1802/decs/p006-pat
  /wise/fops/coadds/18/1808/decs/p020-pat
  /wise/fops/coadds/17/1797/decs/m006-pat
  /wise/fops/coadds/17/1791/decs/m026-pat
  

	W1	W2	W3	W4
WPRO vs. Truth, w/ RMS
WPRO mag sigmas
WAPPco vs. Truth, w/ RMS
WAPPco mag sigmas

Updated: May 6, 2009

• /wise/fops/coadds/34/3470/decs/p280-1
  
• updated WAPPco error model (w / confusion noise)
  
• WPRO bug fixes
  
• new 5x5 PSFs

Table notes:

• white points denote Nblend = 1; red points denote Nblend > 1 (passive deblends)
  
• the reduced CHI^2 distribution comes from the brightest stars (where the Poisson component dominates)
  
• WAPPco refers to the aperture photometry measured from the coadds; WAPP refers to the aperture photometry measured from the frames; WPRO refers to the profile-fitting photometry measured from the frames

	W1	W2	W3	W4
rChi2
rChi2 vs. mag
WPRO vs. WAPPco
WPRO-WAPPco vs. WAPPco
delta mags: WPRO vs. WAPPco
delta mags: WAPP vs. WAPPco
delta mags: WAPP vs. WPRO
delta mags: WPRO repeatability vs. WPRO
delta mags: WPRO repeatability vs. WAPPco
WPRO vs. Truth, w/ RMS
WPRO mag sigmas
WAPPco vs. Truth, w/ RMS
WAPPco mag sigmas
WPRO & WAPPco vs. Truth
WPRO & WAPP vs. Truth
WAPP & WAPPco vs. Truth
WPRO vs. WAPPco

Data Set

WPHot photometry results for the 70 frame simulation set: /wise/fops/coadds/34/3470/decs/p279-1 (Hcon 1), covering roughly ~3 sq. degrees, with a coverage depth of 8 to 10 frames. The total number of WPHOT extractions is 57012.

Example of WPHOT extractions for the simulated field; w1=blue, w2 = green, w3=red.

Updated: Apr 28, 2009 (including new 5x5 PSFs from KAM)

Table notes:

• white points denote Nblend = 1; red points denote Nblend > 1 (passive deblends)
  
• the reduced CHI^2 distribution comes from the brightest stars (where the Poisson component dominates)
  
• WAPPco refers to the aperture photometry measured from the coadds; WAPP refers to the aperture photometry measured from the frames; WPRO refers to the profile-fitting photometry measured from the frames
  
• the reported WAPP mag uncertainty is the SQRT[unbiased sample variance], hence it is a measure of the source repeatibility; the standard deviation of the mean is just that value divided by the SQRT[N] samples; hence, the WPRO and WAPPco mag uncertainties should be compared with the standard deviation of the mean for WAPP (see below).

	W1	W2	W3	W4
rChi2
rChi2 vs. mag
WPRO vs. WAPPco
WPRO-WAPPco vs. WAPPco
delta mags: WPRO vs. WAPPco
delta mags: WAPP vs. WAPPco
delta mags: WAPP vs. WPRO
delta mags: WPRO repeatability vs. WPRO
delta mags: WPRO repeatability vs. WAPPco
WPRO vs. Truth, w/ RMS
WPRO mag sigmas
WAPPco vs. Truth, w/ RMS
WAPPco mag sigmas
WPRO & WAPPco vs. Truth
WPRO & WAPP vs. Truth
WAPP & WAPPco vs. Truth
WPRO vs. WAPPco

Updated: Apr 10, 2009 (including new PSFs from KAM)

	W1	W2	W3	W4
rChi2
rChi2 vs. mag
WPRO vs. WAPPco
WPRO-WAPPco vs. WAPPco
delta mags: WPRO vs. WAPPco
delta mags: WAPP vs. WAPPco
delta mags: WAPP vs. WPRO
WPRO vs. Truth, w/ RMS
WPRO mag sigmas
WAPPco vs. Truth, w/ RMS
WAPPco mag sigmas
WPRO & WAPPco vs. Truth
WPRO & WAPP vs. Truth
WAPP & WAPPco vs. Truth
WPRO vs. WAPPco
WAPP vs. WAPPco

Updated: Mar 9, 2009 (using the old PSFs and jiggered PSFuncs)

	W1	W2	W3	W4
rChi2
WPRO vs. WAPPco
WPRO-WAPPco vs. WAPPco
delta mags: WPRO vs. WAPPco
delta mags: WAPP vs. WAPPco
delta mags: WAPP vs. WPRO
WPRO vs. Truth, w/ RMS
WPRO & WAPPco vs. Truth
WPRO & WAPP vs. Truth
WAPP & WAPPco vs. Truth
WPRO vs. WAPPco
WAPP vs. WAPPco

OLD Results

WPHOT extractions. Approximate center of the field: ecl 30.3 +26.7 deg.

Frame 037, composite with w1==blue, w3==green and w4==red. Overlayed in white are the WPHOT extractions.

Zoomed version, showing the WPHOT extractions overlayed onto the w1(blue), w3(green) and w4(red) composite.

Example of Point-subtracted Frames

W1

W2

W3

W4

Single Frame vs. Multi-frame Measurements

• W1 WAPP
  
• W1 WPRO

• W2 WAPP
  
• W2 WPRO

• W3 WAPP
  
• W3 WPRO

• W4 WAPP
  
• W4 WPRO

Mag vs. Mag Uncertainty (Single vs. Multi)

• W1

• W2

• W3

• W4

Mag vs. Mag Uncertainty (Multiframe)

• W1

• W2

• W3

• W4

WAPP vs. WPRO (Multiframe)

• W1

• W2

• W3

• W4

• binned results, including the mag offset between WPRO and the WAPP aperture photometry.

Source Counts

• W1, source counts showing all extractions (white) and 5-sigma extractions (blue), where the flux and uncertainty come from WPRO. The requirement is 120 uJy.

• W4, source counts showing all extractions (white) and 5-sigma extractions (blue), where the flux and uncertainty come from WPRO. The requirement is 2600 uJy.

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Comparing WPRO/WAPP Photometry with True Source Flux

Example of the pixel distribution in a W1 annulus

Background Annulus

Background Statistics

W1

• W1 WAPP vs. Truth, standard background
  
• W1 WAPP vs. Truth, hmedian background
  
• W1 WPRO vs. Truth, standard background
  
• W1 WPRO vs. Truth, 2-sigma, 10-iteration outlier rejection
  
• W1 WPRO vs. Truth, histogram median (2-iter)

W2

• W2 WAPP vs. Truth, standard background
  
• W2 WAPP vs. Truth, hmedian background
  
• W2 WPRO vs. Truth, standard background
  
• W2 WPRO vs. Truth, 2-sigma, 10-iteration outlier rejection
  
• W2 WPRO vs. Truth, histogram median (2-iter)

W3

• W3 WAPP vs. Truth, standard background
  
• W3 WAPP vs. Truth, hmedian background
  
• W3 WPRO vs. Truth, standard background
  
• W3 WPRO vs. Truth, 2-sigma, 10-iteration outlier rejection
  
• W3 WPRO vs. Truth, histogram median (2-iter)

W4

• W4 WAPP vs. Truth, standard background
  
• W4 WAPP vs. Truth, hmedian background
  
• W4 WPRO vs. Truth, standard background
  
• W4 WPRO vs. Truth, 2-sigma, 10-iteration outlier rejection
  
• W4 WPRO vs. Truth, histogram median (2-iter)

Comments: Notice the faint bias at the faint end. I call this the "hook". Both WAPP and WPRO show this feature. Also notice that WAPP and WPRO have a slight 2-3% offset difference.

WAPP Photometry of WISE Mosaics

• W1 WAPP vs. Truth; mosaic photometry; standard background
  
• W2 WAPP vs. Truth; mosaic photometry; stan dard background
  
• W3 WAPP vs. Truth; mosaic photometry; stan dard background
  
• W4 WAPP vs. Truth; mosaic photometry; stan dard background
  

Comparing Mosaic Photometry with True Source Flux

W1

• Standard median (10-interation outlier rejection)
  
• passive median (2-iteration outlier rejection)
  
• mode (histogram mode)
  
• centroid (histogram centroid)

  Comments: the standard median and the passive median are about the same, with not evidence for the "hook" feature; the "centroid" and mode are clearly producing a background that is too faint, thus creating a bright bias at the faint end.

W2

• Standard median (10-interation outlier rejection)
  
• passive median (2-iteration outlier rejection)
  
• mode (histogram mode)

  Comments: the standard median produces the least amount of scatter, and exhibits a slight faint bias at the faint end; the passive median has a similar bias; the mode is producing a background that is too faint, thus creating a bright bias at the faint end.

W3

• Standard median (10-interation outlier rejection)
  
• passive median (2-iteration outlier rejection)
  
• mode (histogram mode)

  Comments: there is no difference between the two median methods; they both appear to underestimate the background, thus creating a bright bias at the faint end. The mode is even worse in this regard.

W4

• Standard median (10-interation outlier rejection)
  
• passive median (2-iteration outlier rejection)
  
• mode (histogram mode)

  Comments: similar to the results of W3, there is no difference between the two median methods; they both appear to underestimate the background, thus creating a bright bias at the faint end. The mode is even worse in this regard.