Proc. SPIE. 9149, Observatory Operations: Strategies, Processes, and Systems V
KEYWORDS: Observatories, Telescopes, Astronomy, Robotics, Control systems, Space telescopes, Astronomical telescopes, Space operations, Large Synoptic Survey Telescope, Atmospheric Cherenkov telescopes
Observatories are complex scientific and technical institutions serving diverse users and purposes. Their telescopes, instruments, software, and human resources engage in interwoven workflows over a broad range of timescales. These workflows have been tuned to be responsive to concepts of observatory operations that were applicable when various assets were commissioned, years or decades in the past. The astronomical community is entering an era of rapid change increasingly characterized by large time domain surveys, robotic telescopes and automated infrastructures, and – most significantly – of operating modes and scientific consortia that span our individual facilities, joining them into complex network entities. Observatories must adapt and numerous initiatives are in progress that focus on redesigning individual components out of the astronomical toolkit. New instrumentation is both more capable and more complex than ever, and even simple instruments may have powerful observation scripting capabilities. Remote and queue observing modes are now widespread. Data archives are becoming ubiquitous. Virtual observatory standards and protocols and astroinformatics data-mining techniques layered on these are areas of active development. Indeed, new large-aperture ground-based telescopes may be as expensive as space missions and have similarly formal project management processes and large data management requirements. This piecewise approach is not enough. Whatever challenges of funding or politics facing the national and international astronomical communities it will be more efficient – scientifically as well as in the usual figures of merit of cost, schedule, performance, and risks – to explicitly address the systems engineering of the astronomical community as a whole.
We will present aspects of the installation, commissioning, software development, and early operation of several new
robotic telescopes: 1) the 1.2-m MONET/South telescope at Sutherland/ZA, the second Halfmann telescope for the
MONET telescope network (the other telescope has been in operation at McDonald Observatory in Texas since early
2006); 2) a siderostat for a 0.5-m vacuum tower telescope for the new physics building of the Georg-August-Universitat
Göttingen; and 3) new developments for smaller (down to 0.5m) aperture telescopes. Special emphasis will be given to
drive technology: using torque motors we adjust maximum slewing speeds of 10°/sec as standard. Although sufficient
for most projects we are investigating even faster slewing speeds.
The first of two 1.2m MONET robotic telescopes became operational at McDonald Observatory in Texas in spring 2006, the second one will be erected at the South African Astronomical Observatory's Sutherland Station. About 60% of the observing time is dedicated to scientific use by the consortium (Univ. Göttingen, McDonald Obs. and the South African Astron. Obs.) and 40% is for public and school outreach. The alt-az-mounted f/7 RC imaging telescopes are optimized for fast operations, with slewing speeds up to 10°/sec in all axes, making them some of the fastest of their class in the world. The unusual clam-shell enclosures provide the telescopes with nearly unobstructed views of the sky. The new observatory control system fully utilizes the hardware capabilities and permits local, remote, and robotic operations and scheduling, including the monitoring of the weather, electric power, the building, current seeing, all software processes, and the archiving of new data.
In the last few years the ubiquitous availability of high bandwidth networks has changed the way both robotic and non-robotic telescopes operate, with single isolated telescopes being integrated into expanding "smart" telescope networks that can span continents and respond to transient events in seconds. The Heterogeneous Telescope Networks (HTN)* Consortium represents a number of major research groups in the field of robotic telescopes, and together we are proposing a standards based approach to providing interoperability between the existing proprietary telescope networks. We further propose standards for interoperability, and integration with, the emerging Virtual Observatory.
We present the results of the first interoperability meeting held last year and discuss the protocol and transport standards agreed at the meeting, which deals with the complex issue of how to optimally schedule observations on geographically distributed resources. We discuss a free market approach to this scheduling problem, which must initially be based on ad-hoc agreements between the participants in the network, but which may eventually expand into a electronic market for the exchange of telescope time.
Remote Telescope Markup Language (RTML) is an XML-based protocol for the transport of the high-level description of a set of observations to be carried out on a remote, robotic or service telescope. We describe how RTML is being used in a wide variety of contexts: the transport of service and robotic observing requests in the <i>Hands-On Universe</i><sup>TM</sup>, <i>ACP, eSTAR,</i> and <i>MONET</i> networks; how RTML is easily combined with other XML protocols for more localized control of telescopes; RTML as a secondary observation report format for the IVOA's <i>VOEven</i>t protocol; the input format for a general-purpose observation simulator; and the observatory-independent means for carrying out request transactions for the international <i>Heterogeneous Telescope Network </i>(HTN).
Remote Telescope Markup Language (RTML) is an XML-based interface/document format designed to facilitate the exchange of astronomical observing requests and results between investigators and observatories as well as within networks of observatories. While originally created to support simple imaging telescope requests (Versions 1.0-2.1), RTML Version 3.0 now supports a wide range of applications, from request preparation, exposure calculation, spectroscopy, and observation reports to remote telescope scheduling, target-of-opportunity observations and telescope network administration. The elegance of RTML is that all of this is made possible using a public XML Schema which provides a general-purpose, easily parsed, and syntax-checked medium for the exchange of astronomical and user information while not restricting or otherwise constraining the use of the information at either end. Thus, RTML can be used to connect heterogeneous systems and their users without requiring major changes in existing local resources and procedures. Projects as very different as a number of advanced amateur observatories, the global Hands-On Universe project, the MONET network (robotic imaging), the STELLA consortium (robotic spectroscopy), and the 11-m Southern African Large Telescope are now using or intending to use RTML in various forms and for various purposes.
The low resolution spectrograph (LRS) is the first facility instrument on the 9.2m Hobby-Eberly Telescope (HET). The LRS has three operational modes: imaging, long-slit spectroscopy and multi-object spectroscopy (MOS). We present the design and early operations performance of the LRS MOS unit, which provides 13 slitless, each 1.3 arcsec by 15 arcsec, on 19.6 arcsec centers, within the 4 arcmin field of view of the HET. This type of remotely configurable unit was chosen over the more conventional slit masks due to the queue scheduling of the HET, and the instrument's remote location at the prime focus of the telescope. A restricted envelope around the HET focus at the LRS port forced a very compact design. The MOS unit has miniature mechanisms base don custom cross- roller stages and 0.25 mm pitch lead-screws. Geared stepper motors with 10 mm diameters drive the 13 axes at 0.8 micron per step. The precision of the mechanism is far greater than required by the HET plate scale of 205 microns per arcsec, but result in a robust unit. The slitlets were fabricated at the University of Texas by shadow-masking the slit area with a wire and vacuum depositing aluminum onto the silica substrates. Both sides are then coated with MgF<SUB>2</SUB> which serves as an antireflection coating and a protective layer. Web-based software is available for optimizing the orientation of the MOS unit and the placement of slitlets on objects in the field. These setup scan be down loaded to the unit for configuration outside of the beam while the HET is slewing to its next target in the queue, or while the LRS is used in imaging mode for setup on faint objects. The preliminary results presented here are from one commissioning run with the MOS, where the unit appears to be meeting performance specifications.