PSP QA for run 4291, rerun 157

QA produced on Fri Nov 11 12:56:29 EST 2005 with photo version v5_5_11

	Field Quality (nFields=501)
quality	nOK	nHOLE	% HOLE
union	0	501	100.0*
col. 1	0	501	100.0*
col. 2	0	501	100.0*
col. 3	0	501	100.0*
col. 4	0	501	100.0*
col. 5	0	501	100.0*
col. 6	0	501	100.0*

*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 = 0.45
Median = 0.45, min = 0.45, max = 0.45
There are 0 fields ( 0.0%) with PSFwidth > 4.0 arcsec
This run is 501 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	3.00	3.00	3.00	3.00	3.00
col. 2	3.00	3.00	3.00	3.01	3.00
col. 3	3.00	3.00	3.00	3.00	3.00
col. 4	3.00	3.00	3.00	3.00	3.00
col. 5	3.00	3.00	3.00	3.00	3.00
col. 6	3.00	3.00	3.00	3.00	3.00

PSP status plot

	Mean N stars for estimating PSF
band	u	g	r	i	z
col. 1	0.0*	0.0*	0.0*	0.0*	0.0*
col. 2	0.0*	0.0*	0.0*	0.0*	0.0*
col. 3	0.0*	0.0*	0.0*	0.0*	0.0*
col. 4	0.0*	0.0*	0.0*	0.0*	0.0*
col. 5	0.0*	0.0*	0.0*	0.0*	0.0*
col. 6	0.0*	0.0*	0.0*	0.0*	0.0*

*Red entries are triggered by Nstars < 10
Number of stars used for estimating PSF

	Mean m(aperture)-m(psf) Bias (mag)
band	u	g	r	i	z
col. 1	0.00	0.00	0.00	0.00	0.00
col. 2	0.00	0.00	0.00	0.00	0.00
col. 3	0.00	0.00	0.00	0.00	0.00
col. 4	0.00	0.00	0.00	0.00	0.00
col. 5	0.00	0.00	0.00	0.00	0.00
col. 6	0.00	0.00	0.00	0.00	0.00

Aperture Correction Bias plot

	Mean m(aperture)-m(psf) Error (mag)
band	u	g	r	i	z
col. 1	1.00*	1.00*	1.00*	1.00*	1.00*
col. 2	1.00*	1.00*	1.00*	1.00*	1.00*
col. 3	1.00*	1.00*	1.00*	1.00*	1.00*
col. 4	1.00*	1.00*	1.00*	1.00*	1.00*
col. 5	1.00*	1.00*	1.00*	1.00*	1.00*
col. 6	1.00*	1.00*	1.00*	1.00*	1.00*

*Red entries are triggered by
apCorr Error > ( 0.15 0.10 0.10 0.10 0.15) mags in (u g r i z)
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	18.30	18.46	17.53	16.87	15.62
max	18.41	18.59	17.65	17.02	15.79
min	18.05**	18.24**	17.18**	16.47**	15.18**

**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	-0.02	-0.61*	0.03	0.02	0.01
col. 2	-0.03	0.11	-0.01	-0.04	-0.03
col. 3	0.05	0.13	-0.02	0.00	-0.03
col. 4	-0.05	0.13	-0.00	0.01	-0.03
col. 5	0.07	0.15*	-0.01	0.01	0.05
col. 6	-0.03	0.09	0.01	-0.00	0.03

*Red entries are triggered by abs(offset) > 0.15 mag

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	1.02	0.83	1.05	1.16	1.07
col. 2	0.89	1.07	1.09	1.12	1.09
col. 3	1.04	1.12	1.06	1.18	1.07
col. 4	0.94	1.12	1.14	1.13	1.07
col. 5	1.01	1.13	1.04	1.09	1.07
col. 6	0.99	1.11	1.12	1.17	1.04

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).