PSP QA for run 3187, rerun 20

QA produced on Wed Nov 20 13:44:58 CST 2002 with photo version v5_3_55

	Field Quality (nFields=192)
quality	nOK	nHOLE	% HOLE
union	192	0	0.0
col. 1	192	0	0.0
col. 2	192	0	0.0
col. 3	192	0	0.0
col. 4	192	0	0.0
col. 5	192	0	0.0
col. 6	192	0	0.0

PSP status plot

PSF width (FWHM arcsec) statistics for column 6, filter r:
Mean PSF width = 1.25
Median = 1.25, min = 1.17, max = 1.38
There are 0 fields ( 0.0%) with PSFwidth > 4.0 arcsec
This run is 192 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	0.07	0.01	0.01	0.01	0.00
col. 2	0.05	0.02	0.00	0.00	0.00
col. 3	0.06	0.01	0.00	0.01	0.00
col. 4	0.03	0.01	0.00	0.00	0.00
col. 5	0.07	0.01	0.00	0.00	0.00
col. 6	0.02	0.02	0.01	0.00	0.00

PSP status plot

	Mean N stars for estimating PSF
band	u	g	r	i	z
col. 1	33.2	45.4	52.0	52.9	64.4
col. 2	37.1	45.4	54.8	51.8	62.6
col. 3	35.1	47.7	53.5	50.6	65.7
col. 4	41.8	46.1	54.7	52.6	65.7
col. 5	35.8	48.7	56.5	58.1	66.9
col. 6	42.7	50.3	59.9	58.3	69.0

Number of stars used for estimating PSF

	Mean m(aperture)-m(psf) Bias (mag)
band	u	g	r	i	z
col. 1	-0.04	-0.04	-0.03	-0.04	-0.04
col. 2	-0.03	-0.04	-0.03	-0.04	-0.04
col. 3	-0.03	-0.03	-0.03	-0.03	-0.04
col. 4	-0.03	-0.03	-0.03	-0.03	-0.04
col. 5	-0.03	-0.03	-0.03	-0.03	-0.04
col. 6	-0.03	-0.03	-0.03	-0.04	-0.04

Aperture Correction Bias plot

	Mean m(aperture)-m(psf) Error (mag)
band	u	g	r	i	z
col. 1	0.02	0.02	0.01	0.02	0.02
col. 2	0.02	0.02	0.02	0.02	0.02
col. 3	0.02	0.02	0.01	0.02	0.02
col. 4	0.02	0.02	0.01	0.01	0.02
col. 5	0.02	0.02	0.01	0.01	0.02
col. 6	0.02	0.02	0.01	0.01	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	22.47	22.26	21.18	20.38	19.12
max	22.53	22.31	21.22	20.48	19.23
min	22.40	22.21	21.12	20.26	18.97

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	0.00	-0.02	-0.00	0.01	0.02
col. 2	-0.01	-0.01	-0.01	-0.02	-0.06
col. 3	0.02	-0.01	-0.02	0.00	-0.02
col. 4	0.02	0.00	0.01	0.02	-0.01
col. 5	0.00	0.02	0.01	-0.01	0.03
col. 6	-0.03	0.01	0.01	0.00	0.05

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	0.97	1.08	1.00	1.10	1.02
col. 2	0.85	1.00	1.05	1.04	1.06
col. 3	1.00	1.05	1.00	1.08	1.04
col. 4	0.91	1.03	1.06	1.06	1.10
col. 5	0.93	1.08	0.97	1.03	1.04
col. 6	0.94	1.21	1.04	1.08	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).