WFCAM (Wide Field Camera) is an infrared wide-field camera for the UK Infrared Telescope (UKIRT) on Mauna Kea, Hawaii — the most capable IR imaging survey instrument in the Northern Hemisphere. CASU processed all WFCAM data, supporting major surveys including UKIDSS, UHS, and the Galactic Clusters Survey.
WFCAM is an IR wide-field camera for the UK Infrared Telescope on Mauna Kea (UKIRT), and is one of the most capable IR imaging survey instruments in the Northern Hemisphere. It is composed of four Rockwell Hawaii-II 2048×2048 18-micron pixel array detectors, with a pixel scale of 0.4″ (f/2.4) and a field of view per exposure of 0.21 square degrees.
Each detector is divided into quadrants, each of which is divided into eight channels of 128×1024 pixels. The detectors are spaced at 94% of the detector width. Four exposures are required to survey a contiguous area (tile) of 0.8 square degrees.
WFCAM has eight filter housings including the broadband set ZYJHK and two narrow-band filters H2 and Brγ. The average nightly data volume is about 140 GB (2200 images), with peaks up to 230 GB.
Instrument Characteristics
| Detectors | 4 Rockwell Hawaii-II (HgCdTe 2048×2048) |
|---|---|
| Pixel Scale | 0.4″/pixel |
| Field of View | 0.8 sq. deg. (4 pointings per tile) |
| Grasp | 2.38 m² deg² |
| Data Volume | ~140 GB/night |
| Filter Set | Z Y J H K H2 Brγ |
UKIDSS & Surveys
WFCAM was used primarily for the UKIRT Infrared Deep Sky Survey (UKIDSS) — comprising five sub-surveys mapping the sky from the Galactic Plane to deep extragalactic fields. CASU was responsible for all primary data processing: bias subtraction, dark correction, flat-fielding, sky subtraction, astrometric and photometric calibration, and source catalogue generation.
Data Processing
CASU was responsible for processing all data obtained with WFCAM. Data shipped to Cambridge on LTO-I tapes as single-extension FITS files, then read onto RAID disks and converted to MEF format — one FITS container per four detectors. Calibrated data and catalogues were distributed through the WFCAM Science Archive (WSA) at WFAU Edinburgh.
