PSP QA for run 7076, rerun 40

QA produced on Fri Oct 26 01:38:21 CDT 2007 with photo version v5_4_28b

	Field Quality (nFields=520)
quality	nOK	nHOLE	% HOLE
union	405	115	22.1*
col. 1	481	39	7.5*
col. 2	481	39	7.5*
col. 3	473	47	9.0*
col. 4	474	46	8.8*
col. 5	481	39	7.5*
col. 6	473	47	9.0*

*Red entries are triggered by the percentage of unacceptable fields exceeding
5 in any column, or 15 for the union of all columns.
PSP status plot

PSF width (FWHM arcsec) statistics for column 6, filter r:
Mean PSF width = 2.08
Median = 2.01, min = 1.47, max = 3.28
There are 0 fields ( 0.0%) with PSFwidth > 4.0 arcsec
This run is 520 fields long.
PSF width plot for all 30 chips
PSF width derivative plot for all 30 chips

	Mean PSP status (0=OK)
band	u	g	r	i	z
col. 1	0.85	0.51	0.33	0.32	0.13
col. 2	0.59	0.42	0.32	0.35	0.15
col. 3	0.56	0.37	0.33	0.33	0.11
col. 4	0.41	0.33	0.29	0.32	0.13
col. 5	0.43	0.28	0.31	0.28	0.13
col. 6	0.38	0.35	0.30	0.34	0.09

PSP status plot

	Mean N stars for estimating PSF
band	u	g	r	i	z
col. 1	23.5	30.8	34.1	31.6	44.7
col. 2	33.4	31.6	34.3	32.2	45.4
col. 3	27.7	33.9	37.2	33.8	50.3
col. 4	37.6	33.6	37.4	33.5	49.6
col. 5	35.0	35.2	36.3	35.4	45.9
col. 6	41.1	34.9	39.8	36.0	52.3

Number of stars used for estimating PSF

	Mean m(aperture)-m(psf) Bias (mag)
band	u	g	r	i	z
col. 1	-0.11	-0.10*	-0.09	-0.08	-0.09
col. 2	-0.11	-0.09	-0.08	-0.08	-0.09
col. 3	-0.09	-0.09	-0.08	-0.08	-0.08
col. 4	-0.09	-0.08	-0.08	-0.08	-0.08
col. 5	-0.09	-0.08	-0.08	-0.08	-0.08
col. 6	-0.10	-0.09	-0.09	-0.08	-0.08

*Red entries are triggered by
apCorr Bias ( 0.15 0.10 0.10 0.10 0.15) mags in (u g r i z)
Aperture Correction Bias plot

	Mean m(aperture)-m(psf) Error (mag)
band	u	g	r	i	z
col. 1	0.02	0.02	0.02	0.02	0.02
col. 2	0.02	0.02	0.02	0.02	0.02
col. 3	0.02	0.02	0.02	0.02	0.02
col. 4	0.02	0.02	0.02	0.02	0.02
col. 5	0.02	0.02	0.02	0.02	0.02
col. 6	0.02	0.02	0.02	0.02	0.02

Aperture Correction Error plot
A few related auxiliary plots:
Aperture Correction Scatter (w/o bias contribution)
Power-law index for the outer PSF
Kolmogoroff exponents

*Averaged over 6 columns

	Sky brightness* (mag/arsec2)
band	u	g	r	i	z
mean	21.60	21.27	20.45	19.94	18.89
max	22.14	21.94	20.78	20.20	19.09
min	20.60**	20.15**	19.89**	19.50	18.52

**Red entries are triggered by
min Sky < ( 21.2 21.0 20.0 19.2 18.0) mag in (u g r i z)
Sky brightness (in counts) plot
Sky brightness (in mag/arcsec2) plot
Sky derivative plot
Sky colors plot

	Mean Sky Column offsets
band	u	g	r	i	z
col. 1	-0.01	-0.03	-0.02	0.00	0.00
col. 2	-0.03	-0.03	-0.01	-0.03	-0.07
col. 3	0.03	0.00	-0.02	0.00	-0.02
col. 4	0.01	0.02	0.01	0.01	-0.01
col. 5	0.01	0.01	0.01	0.00	0.03
col. 6	-0.01	0.02	0.01	0.01	0.06

The noise is estimated from the width of the sky histogram, corrected
for the dark variance, and normalized by the Poisson value:
norm. spurious noise = sqrt[gain*(sigma_sky^2-dark_var)/sky]
Values significantly larger than 1 indicate the presence of spurious noise.

	Spurious Noise (from sky quartiles)
band	u	g	r	i	z
col. 1	0.99	1.07	1.00	1.10	1.05
col. 2	0.81	1.01	1.05	1.05	1.07
col. 3	1.01	1.04	0.99	1.07	1.04
col. 4	0.92	1.03	1.07	1.06	1.11
col. 5	0.97	1.08	0.97	1.01	1.04
col. 6	0.88	1.02	1.05	1.07	1.03

Spurious Noise plot
Note that bright stars cause single-field spikes which are, for
different bands, aligned in the field number. A temporal increase
in noise can be traced in the r-i-u-z-g order (2 fields shift).