STUDY SUMMARY - IPMU

SUMMARY REPORT
WIDE FIELD FIBER-FED OPTICAL
MULTI-OBJECT SPECTROMETER (WFMOS)
Figure 3.13-3: Read noise versus dwell time for three DECam CCDs manufactured by
LBNL/DALSA. Courtesy of Juan Estrada, Fermi Lab.
Fabrication and testing of 84 CCDs has been budgeted to produce 6 science-grade devices,
safely more than the yield experienced by the 62 CCD Dark Energy Survey Camera. Images will
be dithered in the spatial direction so that cosmetic defects will be removed along with cosmic
rays, allowing specifications for cosmetic defects to be relaxed. Three hundred-μm thick
Hamamatsu CCDs without delta doping (but possibly with JPL’s multilayer coating design) are
offered as a technology fallback option, although this route appears to be more expensive (unless
wavelength coverage or multiplex advantage is sacrificed) and delivers lower performance at
both wavelength extremes.
3.14 System Software
The WFMOS software is responsible for:
• Preparing and managing WFMOS observations in advance.
• Selecting the observations to be made each night.
• Top-level control of WFMOS observations at the Subaru observatory.
• Providing engineering and test software.
• Batch processing of WFMOS data in real time to monitor survey data quality.
3.14.1 Observation Preparation
WFMOS will be capable of observing 2,400 science targets simultaneously in a single observation
and, in total, a given WFMOS survey will yield data for up to 4 million science targets.
Observers need a means of automating the generation of their surveys. The WFMOS observation
preparation software will provide the observer with facilities for selecting the science targets that
make up a WFMOS survey and arranging those targets into a collection of schedulable observations.
It will also provide configuration software for matching targets efficiently to fibers. The
end product of the observation preparation software is a database of observation commands waiting
to be scheduled.
3.14.2 Observation Management
The WFMOS software provides facilities for managing prepared observations. Priorities can
be assigned, extra science targets can be added to observations that have spare fibers, and obser-
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