Survey: UKIDSS Ultra-Deep Survey Telescope: UK Infrared Telescope (UKIRT) Instrument: Wide Field Infrared Camera (WFCAM) Filters: J, H, K Fields: XMM-LSS P.I.: Omar Almaini Reference: 2007ASPC..379..163A Publication date: June 2016 (DR11) URL: http://www.nottingham.ac.uk/astronomy/UDS/ Acknowledgement: The UKIDSS project is defined in Lawrence et al (2007). Further details on the UDS can be found in Almaini et al. (in prep). UKIDSS uses the UKIRT Wide Field Camera (WFCAM; Casali et al, 2007). The photometric system is described in Hewett et al (2006), and the calibration is described in Hodgkin et al. (2009). The pipeline processing and science archive are described in Irwin et al (in prep) and Hambly et al (2008).