10Tb

100Tb

1000Tb

WFCAM processing summary

semesters: 05A, 05B, 06A, 06B, 07Anights: 81, 166, 95, 157, 50 (68%)

50 Tbytes raw data 17 Tbytes compressed <100 Gbytes/night> 75 Tbytes processed data 28 Tbytes compressed

3 million 2kx2k images

storage: 6 x 4Tbyte RAID5 units 2 x 7Tbyte RAID5 units 4 x 10Tbyte RAID6 units

= capacity until end of 07B (grant rollover)

06B features and processing status

missing files

null files

NDR ADU/s

channel edge

pedestals

bar-code

corrupted science frames +

calibrationdarks, flatsskys

impact:

Quality Control parameterssky, images, astrometric, photometric

Nightly photometric zeropoints

06B 200703031

WFCAM photometric calibration 20050908

H

JYZK

WFCAM K-band Zpt semester 05B

Recent processing updates/news

more robust correction for cross-talk 06B ->

photometric solutions inc. extinction corr (all data) [2MASS s:n>10 in J,H,Ks and 0 < J’-Ks’ < 1 -> ce + ext corr]

improved x-y centroiding for all detected objects 06B ->

band-specific astrometric WCS solution (all data)

MAGZPT, MAGZRR, NUMZPT per pointing (all data)

NIGHTZPT, NIGHTZRR, NIGHTNUM /band/night (all data)

direct products to PIs, reprocessing PI data, raw data to PIs

internet transfers casuhelp@ast.cam.ac.uk

Astrometric Calibration 2MASS

Linear solutionper detector

Tabulatedsystematicsfrom stackedresiduals

WCS - ZPN projection

rms < 100 mas

Z

Y

J

H

K

ZP galactic extinction - corrected previously

E(B-V) E(B-V)

Z

Y

J

H

K

Photometric calibration 2MASS

Y-band zeropoint calibration (Z)

Photometric residuals J-band 05B 06A

(illumination correction ++)

J-band 05B Aug -v- Dec flat

07A 1st April bright moon

fin

WFCAM processing steps

prepare - ingest MEFs, check, index, select, preview, process

instrumental signature removal - darks, flats, curtains, cross-talk

sky artefact correction - group master skys by time/ OB

combine - compute shifts, interleave, stack dithers

catalog - detect and parameterise objects [aperture photometry]

classify - morphological classification [curve-of-growth]

astrometry - astrometric calibration per detector

photometry - photometric calibration per pointing [detector gain]

check - examine QC, reject bad products, visual inspection

Example WFCAM illumination correction

2” diamaperture

4” diamaperture