Until a few years ago, the W. M. Keck Observatory (WMKO) did not have a systematic program of instrument maintenance at a level appropriate for a world-leading observatory. We describe the creation of such a program within the context of WMKO’s lean operations model which posed challenges but also guided the design of the system and resulted in some unique and notable capabilities. These capabilities and the flexibility of the system have led to its adoption across the Observatory for virtually all PM’s. The success of the Observatory in implementing the program and its impact on instrument reliability are presented. Lessons learned are reviewed and strategic implications discussed.
Multi-object spectroscopy via custom slitmasks is a key capability on three instruments at the W. M. Keck Observatory.
Before observers can acquire spectra they must complete a complex procedure to align each slit with its corresponding
science target. We developed the Slitmask Alignment Tool (SAT), to replace a complex, inefficient, and error-prone
slitmask alignment process that often resulted in lost sky time for novice and experienced observers alike.
The SAT accomplishes rapid initial mask alignment, prevents field misidentification, accurately predicts alignment box
image locations, corrects for flexure-induced image displacement, verifies the instrument and exposure configuration,
and accommodates both rectangular and trapezoidal alignment box shapes. The SAT is designed to lead observers
through the alignment process and coordinate image acquisition with instrument and telescope moves to improve
efficiencies. By simplifying the process to just a few mouse clicks, the SAT enables even novice observers to achieve
robust, efficient, and accurate alignment of slitmasks on all three Keck instruments supporting multislit spectroscopy,
saving substantial observing time.
The University of California (UC) began operating the Lick Observatory onMount Hamilton, California in 1888. Nearly a
century later, UC became a founding partner in the establishment of theW. M. Keck Observatory (WMKO) in Hawaii, and
it is now a founding partner in the Thirty Meter Telescope (TMT) project. Currently, most UC-affiliated observers conduct
the majority of their ground-based observations using either the Keck 10-meter Telescopes on Mauna Kea or one or more
of the six Lick telescopes now in operation on Mount Hamilton; some use both the Keck and Lick Telescopes. Within the
next decade, these observers should also have the option of observing with the TMT if construction proceeds on schedule.
During the current decade, a growing fraction of the observations on both the Keck and Lick Telescopes have been
conducted from remote observing facilities located at the observer's home institution; we anticipate that TMT observers
will expect the same. Such facilities are now operational at 8 of the 10 campuses of UC and at the UC-operated Lawrence
Berkeley National Laboratory (LBNL); similar facilities are also operational at several other Keck-affiliated institutions.
All of the UC-operated remote observing facilities are currently dual-use, supporting remote observations with either the
Keck or Lick Telescopes.
We report on our first three years of operating such dual-use facilities and describe the similarities and differences
between the Keck and Lick remote observing procedures. We also examine scheduling issues and explore the possibility
of extending these facilities to support TMT observations.
For over a decade, the W. M. Keck Observatory's two 10-meter telescopes have been operated remotely from its Waimea
headquarters. Over the last 6 years, WMKO remote observing has expanded to allow teams at dedicated sites in California
to observe either in collaboration with colleagues in Waimea or entirely from the U.S. mainland. Once an experimental
effort, the Observatory's mainland observing capability is now fully operational, supported on all science instruments
(except the interferometer) and regularly used by astronomers at eight mainland sites.
Establishing a convenient and secure observing capability from those sites required careful planning to ensure that
they are properly equipped and configured. It also entailed a significant investment in hardware and software, including
both custom scripts to simplify launching the instrument interface at remote sites and automated routers employing ISDN
backup lines to ensure continuation of observing during Internet outages.
Observers often wait until shortly before their runs to request use of the mainland facilities. Scheduling these requests
and ensuring proper system operation prior to observing requires close coordination between personnel at WMKO and the
mainland sites. An established protocol for approving requests and carrying out pre-run checkout has proven useful in
The Observatory anticipates enhancing and expanding its remote observing system. Future plans include deploying
dedicated summit computers for running VNC server software, implementing a web-based tracking system for mainland-based
observing requests, expanding the system to additional mainland sites, and converting to full-time VNC operation for
Remote observing is the dominant mode of operation for both Keck Telescopes and their associated instruments. Over 90% of all Keck observations are carried out remotely from the Keck Headquarters in Waimea, Hawaii (located 40 kilometers from the telescopes on the summit of Mauna Kea), and this year represents the tenth anniversary of the start of Keck remote observing from Waimea. In addition, an increasing number of observations are now conducted by geographically-dispersed observing teams, with some team members working from Waimea while others collaborate from Keck remote observing facilities located in California. Such facilities are now operational on four campuses of the University of California and at the California Institute of Technology. Details of the motivation and planning for those facilities and the software architecture on which they were originally based are discussed in several previous reports. The most recent of those papers reported the results of various measurements of interactive performance as a function of alternative networking protocols (e.g., ssh, X, VNC) and software topologies. This report updates those results to reflect performance improvements that have occurred over the past two years as a result of upgrades to hardware, software, and network configurations at the respective sites. It also explores how the Keck remote observing effort has evolved over the past decade in response to the increased number and diversity of Keck instruments and the growing number of mainland remote observing sites.
The DEep Imaging Multi-Object Spectrograph (DEIMOS) was commissioned on Keck II in June 2002. It employs a closed-loop flexure compensation system (FCS) to measure and compensate for image motion resulting from gravitationally-induced flexure of spectrograph elements. The FCS utilizes a set of fiber-fed FCS light sources located at the edges of the instrument focal plane to produce a corresponding set of spots on a pair of FCS CCD detectors located on either side of the science CCD mosaic. (This FCS light follows the same light path through the instrument as the science spectra.) During science exposures, the FCS detectors are read out several times per minute. These FCS images are analyzed in real time to measure any translational motion of the FCS spots and to derive correction signals; those signals drive active optical mechanisms
which steer the spots back to their nominal positions, thus stabilizing the images on the FCS CCDs and the science mosaic. This paper describes the commissioning of the DEIMOS FCS system, its
continued evolution during its first 18 months of operation on the
telescope, and its operational performance over that period. We describe the various challenges encountered while refining the initial FCS prototype (deployed at commissioning) into a fully-operational and highly-reliable system that is now an essential component of the instrument. These challenges include: reducing stray light from FCS light sources to an acceptable level; resolving interactions between FCS acquisition and slit mask alignment; providing robust rejection of cosmic ray events in
FCS images; implementing a graphical user interface for FCS control and status.
Remote observing is the dominant mode of operation for both Keck
Telescopes and their associated instruments. Over 90% of all Keck
observations are carried out remotely from the Keck Headquarters in
Waimea, Hawaii (located 40 kilometers from the telescopes on the summit of Mauna Kea). In addition, an increasing number of observations are now conducted by geographically-dispersed observing teams, with some team members working from Waimea while others collaborate from Keck remote observing facilities located in California. Such facilities are now operational on the Santa Cruz and San Diego campuses of the University of California, and at the California Institute of Technology in Pasadena.
This report describes our use of the X and VNC protocols for providing
remote and shared graphical displays to distributed teams of observers
and observing assistants located at multiple sites. We describe the
results of tests involving both protocols, and explore the limitations
and performance of each under different regimes of network bandwidth
and latency. We also examine other constraints imposed by differences
in the processing performance and bit depth of the various frame buffers used to generate these graphical displays.
Other topics covered include the use of ssh tunnels for securely encapsulating both X and VNC protocol streams and the results of tests of ssh compression to improve performance under conditions of limited network bandwidth. We also examine trade-offs between different topologies for locating VNC servers and clients when sharing
displays between multiple sites.
This paper documents the astrometric slitmask design, submission,
fabrication, control and configuration tools used for two large
spectrographs at W. M. Keck Observatory on Mauna Kea, Hawai'i.
For supplemental illustrations and documents, including an online
version of the poster and interactive demos, we refer the reader to