An important part of any new observatory construction project is to address the needs of long-term operations. The Giant Magellan Telescope Project, currently in the design phase, addresses these needs in several ways. We have hired an operations expert and have several other staff experienced in various aspects of observatory operations. Our high-level documents include an Observatory Operations Concept, describing how the observatory and its subsystems will work together to provide a high-level of service and performance to the astronomers that form their user base. It is also important to estimate the resources required for operations, and to develop a plan for the transition from project to operations.
Developing system behaviors early in the design process is an important tool to acquire more knowledge about interfaces and uncover requirements. The GMT design has progressed far enough that we are mostly writing more evolved behaviors, using the knowledge of existing requirements and interfaces, and describing in more detail the behaviors. Nevertheless, we are uncovering new requirements, and informing preliminary hazard analysis as we describe various operational tasks. Over 300 behaviors were identified by the subsystem teams in collaboration with the Systems Engineering team.
The Observatory Operations Concept outlines a set of “critical” behaviors, which those which require high reliability, the most resources, or are otherwise notable. These include exchanges of the cells holding the primary mirror segments, mirror recoating, installation and maintenance of instruments, cleaning the major optics, and recovering from major seismic events.
We are taking a similar approach to that used by software and controls, where we identify the “high level user stories” to inform the development regarding states, status, actors, actions and events.
Software and controls is taking a similar approach, using high-level “user stories” to inform their software interfaces.
This contribution will describe in more detail the goals of the Observatory Operations Concept and system behaviors. It will describe the tools and products of system behaviors. It will provide some examples of how system behaviors studies have led to significant requirements robustness and better informed design decisions.
Validation of Computational Fluid Dynamics (CFD) solutions using experimental data is critical as CFD simulations are regularly used for site characterization and design analysis of Extremely Large Telescopes (ELT). Site testing data for wind, temperature and optical turbulence are used to validate the GMT CFD model configuration for the construction site at Las Campanas Peak in Northern Chile. CFD simulations, both steady-state and unsteady, combined with the corresponding seeing models are performed and estimates of the Ground Layer (GL) optical turbulence are calculated. Comparisons with wind, temperature and optical turbulence profiles are made that show a good match between simulated and observed data.
The Giant Magellan Telescope Project is in the construction phase. Production of the primary mirror segments is underway with four of the seven required 8.4m mirrors at various stages of completion and materials purchased for segments five and six. Development of the infrastructure at the GMT site at Las Campanas is nearing completion. Power, water, and data connections sufficient to support the construction of the telescope and enclosure are in place and roads to the summit have been widened and graded to support transportation of large and heavy loads. Construction pads for the support buildings have been graded and the construction residence is being installed. A small number of issues need to be resolved before the final design of the telescope structure and enclosure can proceed and the GMT team is collecting the required inputs to the decision making process. Prototyping activities targeted at the active and adaptive optics systems are allowing us to finalize designs before large scale production of components begins. Our technically driven schedule calls for the telescope to be assembled on site in 2022 and to be ready to receive a subset of the primary and secondary mirror optics late in the year. The end date for the project is coupled to the delivery of the final primary mirror segments and the adaptive secondary mirrors that support adaptive optics operations.
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.
The Infrared Processing and Analysis Center (IPAC) and the W. M. Keck Observatory (WMKO) operate an archive for the Keck Observatory. At the end of 2013, KOA completed the ingestion of data from all eight active observatory instruments. KOA will continue to ingest all newly obtained observations, at an anticipated volume of 4 TB per year. The data are transmitted electronically from WMKO to IPAC for storage and curation. Access to data is governed by a data use policy, and approximately two-thirds of the data in the archive are public.
A collaboration between the W. M. Keck Observatory (WMKO) in Hawaii and the NASA Exoplanet Science Institute (NExScI) in California, the Keck Observatory Archive (KOA) was commissioned in 2004 to archive observing data from WMKO, which operates two classically scheduled 10 m ground-based telescopes. The observing data from Keck is not suitable for direct ingestion into the archive since the metadata contained in the original FITS headers lack the information necessary for proper archiving. Coupled with different standards among instrument builders and the heterogeneous nature of the data inherent in classical observing, in which observers have complete control of the instruments and their observations, the data pose a number of technical challenges for KOA. For example, it is often difficult to determine if an observation is a science target, a sky frame, or a sky flat. It is also necessary to assign the data to the correct owners and observing programs, which can be a challenge for time-domain and target-of-opportunity observations, or on split nights, during which two or more principle investigators share a given night. In addition, having uniform and adequate calibrations are important for the proper reduction of data. Therefore, KOA needs to distinguish science files from calibration files, identify the type of calibrations available, and associate the appropriate calibration files with each science frame. We describe the methodologies and tools that we have developed to successfully address these difficulties, adding content to the FITS headers and "retrofitting" the metadata in order to support archiving Keck data, especially those obtained before the archive was designed. With the expertise gained from having successfully archived observations taken with all eight currently active instruments at WMKO, we have developed lessons learned from handling this complex array of heterogeneous metadata that help ensure a smooth ingestion of data not only for current but also future instruments, as well as a better experience for the archive user.
The Keck Observatory Archive (KOA), which began curating and serving data in 2004, was developed many years after
the W. M. Keck Observatory (WMKO) came into operations. Since much of the data produced from instruments on the
twin Keck telescopes were never designed with the archive in mind, the metadata contained in the original FITS headers
were not adequate for proper archiving. Some examples of the challenges facing the process of making the data suitable
for archiving include: assigning data to the correct owner and program, especially on nights split between two or more
PIs; distinguishing science files from calibration files; and identifying the type of calibration. We present some software
techniques that prepare and evaluate the data, adding content to the FITS headers and "retrofitting" the metadata in order
to support archiving Keck legacy data. We also describe tools developed to ensure a smooth ingestion of data for current
and future instruments. We present briefly our method for controlling and monitoring the data transfer between WMKO
in Hawaii and the NASA Exoplanet Science Institute (NExScI) in California, where the data are physically hosted.
In order to validate various assumptions about the operating environment of the Thirty Meter Telescope (TMT),
to validate the modeling packages being used to guide the design work for the TMT and to directly investigate
the expected operation of several subsystems we have embarked on an extensive campaign of environmental
measurements at the Keck telescopes. We have measured and characterized the vibration environment around
the observatory floor and at certain locations on the telescope over a range of operating conditions. Similarly the
acoustic environment around the telescope and primary mirror has been characterized for frequencies above 2 Hz.
The internal and external wind and temperature fields are being measured using combined sonic anemometer
and PRT sensors. We are measuring the telescope position error and drive torque signals in order to investigate
the wind induced telescope motions. A scintillometer mounted on the telescope is measuring the optical
turbulence inside the telescope tube. This experimental work is supplemented by an extensive analysis of telescope
and engineering sensor log files and measurements, primarily those of accelerometers located on the main
telescope optics, primary mirror segment edge sensor error signals (residuals), telescope structure temperature
measurements and the telescope status information.
Natural Guide Star (NGS) and Laser Guide Star (LGS) Adaptive Optics (AO) have been offered for routine science
operations to the W. M. Keck Observatory community since 2000 and late 2004, respectively. The AO operations team
is now supporting ~100 nights of AO observing with four different instruments, including over fifty nights of LGS AO
per semester. In this paper we describe improvements to AO operations to handle the large number of nights and to
accommodate the recent upgrade to the wavefront sensor and wavefront controller. We report on the observing
efficiency, image quality, scientific productivity, impact analysis from satellite safety procedures and discuss the support
load required to operate AO at Keck. We conclude the paper by presenting our plans for dual LGS AO operations with
Keck I - Keck II LGS, starting in 2009.
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
We describe the system to monitor and analyze the duty cycle of observing nights at the W. M. Keck Observatory. The
system is almost completely automated, and relies predominantly on existing data. Lists of discrete "events" during the
night are compiled (e.g. the start of a science exposure), and the sequence of events is interpreted as an "activity" (e.g.
collecting science photons). The metrics system has proven extremely valuable, allowing scientists and engineers to
identify the largest causes of inefficiency, and to quantify their impacts. This has led directly to prioritization decisions
in upgrades and repairs at the Observatory.
Observatories using laser guide star (LGS) adaptive optics (AO) systems need to implement safety systems to protect
aircraft from being illuminated by the lasers. These systems are made up of a combination of control measures and
procedures. In the USA the Federal Aviation Administration (FAA) is responsible for protecting aircraft and issues a
determination of no-objection to the use of lasers in the navigable airspace before operations can begin. To date, the
FAA has required all observatories with LGS systems to use human aircraft spotters as part of the aircraft safety system.
This paper discusses how we might go about developing an automated alternative that is more reliable and less
expensive than using spotters and is also acceptable to the FAA. Specific challenges are identified and discussed. These
challenges include understanding the FAA perspective on issues related to aircraft safety and lasers, understanding the
FAA evaluation and approval process for specific control measures, safety systems and operational procedures, working
with appropriate standards committees to develop requirements and performance validation plans which lead to
quantifiable confidence. We would also like to solicit collaboration from within the Mauna Kea astronomy community
and also the broader astronomical community.
The W. M. Keck Observatory has completed the development and initial deployment of MAGIQ, the Multi-function
Acquisition, Guiding and Image Quality monitoring system. MAGIQ is an integrated system for acquisition, guiding and
image quality measurement for the Keck telescopes. This system replaces the acquisition and guiding hardware and
software for existing instruments at the Observatory and is now the standard for visible wavelength band acquisition
cameras for future instrumentation. In this paper we report on the final design and implementation of this new system,
which includes three major components: a visible wavelength band acquisition camera, image quality measurement
capability, and software for acquisition, guiding and image quality monitoring. The overall performance is described, as
well as the details of our approach to integrating low order wavefront sensing capability in order to provide closed loop
control of telescope focus.
Laser Guide Star Adaptive Optics (LGS AO) has been offered to Keck II visiting astronomers since November 2004. From the few nights of shared-risk science offered at that time, the LGS AO operation effort has grown to supporting over fifty nights of LGS AO per semester. In this paper we describe the new technology required to support LGS AO, give an overview of the operational model, report observing efficiency and discuss the support load required to operate LGS AO. We conclude the paper by sharing lessons learned and the challenges yet to be faced.
The Laser Guide Star Adaptive Optics (LGS AO) at the W.M. Keck Observatory is the first system of its kind being used to conduct routine science on a ten-meter telescope. In 2005, more than fifty nights of LGSAO science and engineering were carried out using the NIRC2 and OSIRIS science instruments. In this paper, we report on the typical performance and operations of its LGS AO-specific sub-systems (laser, tip-tilt sensor, low-bandwidth wavefront sensor) as well as the overall scientific performance and observing efficiency. We conclude the paper by describing our main performance limitations and present possible developments to overcome them.
An optical-wavelength polarimetry module has been in use for the past ten years at the W.M. Keck Observatory. The module is used in conjunction with the LRIS imaging spectrograph. It provides either imaging polarimetry or spectropolarimetry across the full wavelength range of the instrument (320-1100 nm). The design, performance, and limitations of the polarimetry module are described, along with a sampling of science results.
Studies of the cosmic gamma-ray bursts (GRBs) and their host galaxies are now starting to provide interesting or even unique new insights in observational cosmology. Observed GRB host galaxies have a median magnitude R~25 mag, and show a range of luminosities, morphologies, and star formation rates, with a median redshift z~1. They represent a new way of identifying a population of star-forming galaxies at cosmological redshifts, which is mostly independent of the traditional selection methods. They seem to be broadly similar to the normal field galaxy populations at comparable redshifts and magnitudes, and indicate at most a mild luminosity evolution over the redshift range they probe. Studies of GRB optical afterglows seen in absorption provide a powerful new probe of the ISM in dense, central regions of their host galaxies, which is complementary to the traditional studies using QSO absorption line systems. Some GRB hosts are heavily obscured, and provide a new way to select a population of cosmological sub-mm sources. A census of detected optical tranistents may provide an important new way to constrain the total obscured fraction of star formation over the history of the universe. Finally, detection of GRB afterglows at high redshifts (z>6) may provide a unique way to probe the primordial star formation, massive IMF, early IGM, and chemical enrichment at the end of the cosmic reionization era.
The Keck II Adaptive Optics system and the NIRC2 camera provide a unique facility for high angular resolution imaging and spectroscopy in the near infrared. In this paper, we present the result of a unique project to map the entire surface of Io in the thermal infrared (Lp band centered at 3.8 μm). This project was undertaken by a team from the W. M. Keck Observatory and UC Berkeley to illustrate the power of this instrumentation. The 75-milliarcsec-resolution images, corresponding to ~200 km of linear spatial resolution on Io, have been combined to build a thermal infrared map of the entire satellite. We have identified 26 hot spots including one that was undetected by the Galileo mission. A movie and a Java applet featuring a volcanically active rotating satellite were created.
Differential Atmospheric Refraction (DAR) reduces image quality on ground-based 10-m telescopes equipped with Adaptive Optics (AO). Particularly affected are the long exposure data taken in narrow-band imaging or spectroscopic mode. The magnitude of the DAR is a function of the effective wavelength of the wavefront sensor detector, meteorological variables, the observing wavelength and the elevation of the observation.
In this paper, we present the approach taken by the Keck Adaptive Optics team to compensate for DAR during AO observing. This paper will present a description and illustration of the problem and our solution to it, including some implementation details. This paper also presents some tips on observing techniques, along with some details on current performance, a description of the issues limiting the performance, and our plans for the future.
Gamma-ray burst astronomy has undergone a revolution in the last three years, spurred by the discover of fading long- wavelength counterparts. We now know that at least the long duration GRBs lie at cosmological distances with estimated electromagnetic energy release of 1051-1053 erg, making these the brightest explosions in the Universe. In this article we review the current observational state of the long-lived 'afterglow' emission that accompanies GRBs at X-ray, optical, and radio afterglow wavelengths. We then discuss the insights these observations have given to the progenitor population, the energetics of the GRB events, and the physics of the afterglow emission. We focus particular attention on the evidence linking GRBs to the explosion of massive stars. Throughout, we identify remaining puzzles and uncertainties, and emphasize promising observations tools for addressing them. The imminent launch of HETE-2, the increasingly sophisticated and coordinated ground-based and space-based observations, and the increasing availability of 10-m class optical telescopes have primed this field for fantastic growth.