WPHOT Photometry
|
WISE Simulated Images of a Mid-Latitude Field: WPHOT Photometry |
|
| W3 | W4 | |
| WPRO vs. Truth, RMS | 
| 
|
| W1 | W2 | W3 | W4 | ||||||||||||||||
| WPRO vs. Truth, w/ RMS | 
| 
| 
| 
WPRO mag sigmas |
WAPPco vs. Truth, w/ RMS |
WAPPco mag sigmas |
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| W1 | W2 | W3 | W4 | ||||||||||||||||
| WPRO vs. Truth, w/ RMS | 
| 
| 
| 
WPRO mag sigmas |
WAPPco vs. Truth, w/ RMS |
WAPPco mag sigmas |
|
Table notes:
| 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. |
Table notes:
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.
|
W1 |
W2 |
W3 |
W4 |
 Background Annulus |
|
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.
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.
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.
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.
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.
WAPP Photometry of WISE Mosaics
W1
Comments: The "hook" feature is not present in the mosaic photometry.
Comparing Mosaic Photometry with True Source Flux
Aperture photometry was carried out on the AWAIC mosaics using
the IRAF package "phot" with different background estimation techniques.
W1
W2
W3
W4
Last update - [28 Apr 2009]
T.H. Jarrett (IPAC/SSC)
