  The Submillimetre Common User Bolometer Array 2 (SCUBA-2) is an instrument
operating on the 15-m James Clerk Maxwell Telescope, nominally consisting of
5120 bolometers in each of two simultaneous imaging bands centred over 450 and
850 um. The camera is operated by scanning across the sky and recording data at
a rate of 200 Hz. As the largest of a new generation of multiplexed kilopixel
bolometer cameras operating in the (sub)millimetre, SCUBA-2 data analysis
represents a significant challenge. We describe the production of maps using
the Sub-Millimetre User Reduction Facility (SMURF) in which we have adopted a
fast, iterative approach to map-making that enables data reduction on single,
modern, high-end desktop computers, with execution times that are typically
shorter than the observing times. SMURF is used in an automated setting, both
at the telescope for real-time feedback to observers, as well as for the
production of science products for the JCMT Science Archive at the Canadian
Astronomy Data Centre. Three detailed case studies are used to: (i) explore
convergence properties of the map-maker using simple prior constraints (Uranus
-- a point source); (ii) achieve the white-noise limit for faint point-source
studies (extragalactic blank-field survey of the Lockman Hole); and (iii)
demonstrate that our strategy is capable of recovering angular scales
comparable to the size of the array footprint (approximately 5 arcmin) for
bright extended sources (star-forming region M17).
