The UKIRT wide-field camera (WFCAM): commissioning and performance on the telescope

The UKIRT Wide-Field Camera (WFCAM) was commissioned in two phases between October and December 2004, and March and April 2005. It has been carrying out full-scale sky survey operations since May 2005. This paper describes the commissioning process and compares actual performance on the telescope with specifications in four key areas: optical image quality including delivered FWHM and ghosting etc., noise and sensitivity in the infrared and on the visible autoguider, array artifacts such as crosstalk and persistent images, and observing efficiency. A comprehensive program of science verification was carried out before commencing the UKIRT Infrared Deep Sky Survey (UKIDSS).