The Thirty Meter Telescope (TMT) project is a partnership between ACURA, AURA, Caltech, and the University of California. The Telescope Control System (TCS) for TMT is comprised of many subsystems. The TCS Supervisory Controller is responsible for pointing the telescope via an embedded pointing kernel, sequencing commands to the telescope systems, responding to errors and alarms and interacting with the telescope safety system. This paper describes the conceptual design for the Supervisory Controller and addresses the integration with the other TMT software systems. The requirements are discussed in terms of producing a functional, usable, safe, reliable and maintainable system.

The Large Synoptic Survey Telescope (LSST) will be a large, wide-field ground-based telescope designed to obtain sequential images of the entire visible sky every few nights. The LSST, in spite of its large field of view and short 15 second exposures, requires a very accurate pointing and tracking performance. The high efficiency specified for the whole system implies that observations will be acquired in blind pointing mode and tracking demands calculated from blind pointing as well. This paper will provide a high level overview of the LSST Control System (LCS) and details of the Telescope Control System (TCS), explaining the characteristics of the system components and the interactions among them. The LCS and TCS will be designed around a distributed architecture to maximize the control efficiency and to support the highly robotic nature of the LSST System. In addition to its control functions, the LCS will capture, organize and store system wide state information, to make it available for monitoring, evaluation and calibration processes. An evaluation of the potential communications middleware software to be utilized for data transport, is also included.

The Expanded Very Large Array (EVLA) project is the next generation instrument for high resolution and high sensitivity long-millimeter to short-meter wavelength radio astronomy. It is currently funded by NSF, with completion scheduled for 2012. The EVLA will upgrade the VLA with new feeds, receivers, data transmission hardware, correlator, and a new software system to enable the instrument to achieve its full potential. This software includes both that required for controlling and monitoring the instrument and that with emphasis on the scientific functions related to the telescope. The primary goals of the software are: to maximize the scientific return of the EVLA; provide ease of use, for both novices and experts; exploit commonality amongst all NRAO telescopes where possible. The software design methodology includes detailed initial use-cases and requirements from the scientists, intimate interaction between the scientists and the programmers during design and implementation, and rapid prototyping and development cycles (as short as a week). This manuscript is an update of a similar description published for the SPIE meeting two years ago; a more full description and background can be found there, while this document concentrates on the changes since then, specifically in the area of the high level design and pre-observing software (user authentication; proposal preparation, submission, and handling; observation preparation; and observation scheduling).

Since 2003, the monitor and control software systems for the Robert C. Byrd Green Bank Telescope (GBT) have been substantially redesigned to make the telescope easier to use. The result is the release of the Astronomer's Integrated Desktop (Astrid), an observation management platform used to create and submit scheduling blocks, monitor their progress on the telescope, and provide a real time, quick look data display. Using Astrid, the astronomer launches one application and has access to all of the software, documentation, and feedback facilities that are required to conduct an interactive observing session. These systems together provide a common look and feel for GBT software applications, enable offline observation preparation, and facilitate dynamic scheduling and remote observing.

The ALMA Common Software (ACS) provides the software infrastructure used by ALMA and by several other telescope projects, thanks also to the choice of adopting the LGPL public license. ACS is a set of application frameworks providing the basic services needed for object oriented distributed computing. Among these are transparent remote object invocation, object deployment and location based on a container/component model, distributed error, alarm handling, logging and events. ACS is based on CORBA and built on top of free CORBA implementations. Free software is extensively used wherever possible. The general architecture of ACS was presented at SPIE 2002. ACS has been under development for 6 years and it is midway through its development life. Many applications have been written using ACS; the ALMA test facility, APEX and other telescopes are running systems based on ACS. This is therefore a good time to look back and see what have been until now the strong and the weak points of ACS in terms of architecture and implementation. In this perspective, it is very important to analyze the applications based on ACS, the feedback received by the users and the impact that this feedback has had on the development of ACS itself, by favoring the development of some features with respect to others. The purpose of this paper is to describe the results of this analysis and discuss what we would like to do in order to extend and improve ACS in the coming years, in particular to make application development easier and more efficient.

An alarm system is a cornerstone service in every computer controlled environment. Its purpose is the notification of exceptional conditions in the system requiring an intervention from the staff. The specifications for the alarm system in the Alma Common Software (ACS) require not only that each alarm has to be shown to operators in a short time, but also that correlated alarms must be "reduced" and presented in compact form in such a way that operators are able to easily identify the root cause for an abnormal condition. In the development of ACS we always investigate the availability of adequate implementations before writing a service from scratch. Such an implementation, the CERN Laser Alarm System, developed for the Large Hadron Collider, was fulfilling and exceeding our requirements. We have therefore started a pilot collaboration project to verify the possibility of integrating Large Hadron Collider Alarm Service (LASER) into ACS. A test suite was developed to demonstrate that the full chain of events starting from the publication of new alarms from a set of sources to their representation in a GUI happened as expected. Particular attention was given to the reduction mechanism for its importance in helping the operators in finding the real cause of each problem in a short time. The project showed that it is possible to integrate two different software systems if they are written with well defined interface and have a similar infrastructure. In this paper we describe the modifications we introduce to integrate CERN LASER into ACS.

Linking ground based telescopes with astronomical satellites, and using the emerging field of intelligent agent architectures to provide crucial autonomous decision making in software, we have combined data archives and research class robotic telescopes along with distributed computing nodes to build an ad-hoc peer-to-peer heterogeneous network of resources. The eSTAR Project* uses intelligent agent technologies to carry out resource discovery, submit observation requests and analyze the reduced data returned from a meta-network of robotic telescopes. We present the current operations paradigm of the eSTAR network and describe the direction of in which the project intends to develop over the next several years. We also discuss the challenges facing the project, including the very real sociological one of user acceptance.

Over the past four years we have seen continued advancement in network technology and how those technologies are beginning to enable astronomical science. Even though some sociological aspects are hindering full cooperation between most observatories and telescopes outside of their academic or institutional connections, an unprecedented step during the summer of 2005 was taken towards creating a world-wide interconnection of astronomical assets. The Telescope Alert Operations Network System (TALONS), a centralized server/client bi-directional network developed and operated by Los Alamos National Laboratory, integrated one of its network nodes with a node from the eScience Telescopes for Astronomical Research (eSTAR), a peer-to-peer agent based network developed and operated by The University of Exeter. Each network can act independently, providing support for their direct clients, and by interconnection provide local clients with access to; outside telescope systems, software tools unavailable locally, and the ability to utilize assets far more efficiently, thereby enabling science on a world-wide scale. In this paper we will look at the evolution of these independent networks into the worlds first heterogeneous telescope network and where this may take astronomy in the future. We will also examine those key elements necessary to providing universal communication between diverse astronomical networks.

The James Webb Space Telescope (JWST) will use an event-driven system architecture to provide efficient and flexible operations as initiated by a simplified, high-level ground command interface. Event-driven operations is provided through the use of an on-board COTS JavaScript engine hosted within the payload flight software. After presenting the overall software architecture, we summarize the trade study that led to the selection of a commercial JavaScript interpreter and review our experiences developing scripts over the past year. Our script development approach is based upon the process successfully used at Space Telescope Science Institute for the last six Hubble Space Telescope science instruments. The major characteristics of our process are 1) coordinated development of the operational scripts and the flight software, 2) an incremental buildup of the operational requirements, and 3) recurring integrated testing. Our iterative script implementation process addresses how to gather requirements from a geographically dispersed team, and then how to design, build, and test the script software to accommodate the changes that are inevitable as flight hardware is built and tested. The concurrent development of the operational scripts and the flight software enables early and frequent "test-as-you-will-fly" verification, thus reducing the risk of on-orbit software problems.

We present MOPEX - a software package for astronomical image processing and display. The package is a combination of command-line driven image processing software written in C/C++ with a Java-based GUI. The main image processing capabilities include creating mosaic images, image registration, background matching, point source extraction, as well as a number of minor image processing tasks. The combination of the image processing and display capabilities allows for much more intuitive and efficient way of performing image processing. The GUI allows for the control over the image processing and display to be closely intertwined. Parameter setting, validation, and specific processing options are entered by the user through a set of intuitive dialog boxes. Visualization feeds back into further processing by providing a prompt feedback of the processing results. The GUI also allows for further analysis by accessing and displaying data from existing image and catalog servers using a virtual observatory approach. Even though originally designed for the Spitzer Space Telescope mission, a lot of functionalities are of general usefulness and can be used for working with existing astronomical data and for new missions. The software used in the package has undergone intensive testing and benefited greatly from effective software reuse. The visualization part has been used for observation planning for both the Spitzer and Herschel Space Telescopes as part the tool Spot. The visualization capabilities of Spot have been enhanced and integrated with the image processing functionality of the command-line driven MOPEX. The image processing software is used in the Spitzer automated pipeline processing, which has been in operation for nearly 3 years. The image processing capabilities have also been tested in off-line processing by numerous astronomers at various institutions around the world. The package is multi-platform and includes automatic update capabilities. The software package has been developed by a small group of software developers and scientists at the Spitzer Science Center. It is available for distribution at the Spitzer Science Center web page.

The software for the Thirty Meter Telescope (TMT) is currently in the specification and design phase. A decision was made early on to provide a common software package that will provide basic infrastructure and services to be used by all project software packages. A roadmap for defining Common Software was written. The first roadmap step of defining what should be included in common software was accomplished by analyzing similar projects. The result was the definition of a reference architecture for end-to-end observatory software systems called the Observatory Software Domain Architecture. This architecture was then used to define the specifications for the TMT common software. This paper describes the roadmap, the reference architecture, and the current definition of TMT common software.

The Thirty Meter Telescope (TMT) is a collaborative project between the California Institute of Technology (CIT), the University of California (UC), the Association of Universities for Research in Astronomy (AURA) and the Association of Canadian Universities for Research in Astronomy (ACURA). Current activity is focused on the design and development phase (DDP) of all systems. For the TMT to achieve seeing and diffraction limited performance, the telescope-related software systems will have to work in concert to precisely control all 738 primary mirror (M1) segments along with the active secondary mirror (M2) and an articulated tertiary mirror (M3). In this paper we discuss the conceptual design of the software control systems for these surfaces and their integration into a cohesive whole.

When two telescopes share a single telescope mount, as is the case for the Large Binocular Telescope, the control system has to both position the mount and adjust the alignment of the two optical systems if the telescopes are going to point and track the way a single telescope is expected to do. The alignments of the two systems depend on the flexure models, target position and observing wavelength all of which may be different for the two telescopes. Furthermore these differences change as the telescope tracks. This paper describes how the pointing algorithms for a single telescope have been adapted to calculate the optimum position for the telescope mount and the necessary adjustments to the optical alignments of two telescopes. It also shows how the same algorithms can be used to support the rather more common case of a chopping secondary (or other mirror) where the tips and tilts for the chopping mirror are generated by treating the two (or more) chop states as if they were independent telescopes. This delivers a chop throw that takes into account differential refraction and all other similar effects.

The 1m balloon-borne solar telescope Sunrise will be equipped with a wave-front sensing system for automatic in-flight focusing and alignment of the telescope and for high-precision image tracking. A six-element wavefront sensor measures low order aberrations of the telescope, including defocus and coma. The correction is achieved by moving the focusing mirror and the telescope secondary, respectively, in a closed-loop circuit. The same system measures image motion. The instrument requirements for the tracking are a dynamical range of about 30 Hz and a precision of about 0.005 arcs in the sky. The image motion signal feeds a closed-loop control system that drives both the tip-tilt mirror assembly and the mirrors that are needed for focusing and alignment. The tip-tilt unit is a dual-stage system, built at the Kiepenheuer-Insitut, consisting of a slow component with a large range of about 60 arcs and a fast component with a short range and high bandwidth. A breadboard-version of the Correlating Wavefront Sensor has been successfully tested at the German Vacuum Tower Telescope on Tenerife in summer of 2005. A closed-loop bandwidth of 80 Hz was measured for the tracking system. The wave-front sensor detected image aberrations pre-set by the telescope's adaptive optics system with the required accuracy. Sunrise will be flown in long duration stratospheric balloon flights, with a first scientific flight in 2009.

The Canada-France-Hawaii Telescope (CFHT) is commissioning a new Wide field Infrared Camera (WIRCam) that uses a mosaic of 4 HAWAII-2RG near- infrared detectors manufactured by Rockwell. At the heart of the instrument is an On-Chip Guiding System (OCGS) that exploits the unique parallel science/guide frame readout capability of the HAWAII-2RG detectors. A small sub sample of each array is continuously read at a rate of up to 50 Hz while the integration of the science image is ongoing with the full arrays (read at a maximal rate of 1.4 s per full frame). Each of these guiding windows is centered on a star to provide an error signal for the telescope guiding. An Image Stabilizer Unit (ISU) (i.e. a tip-tilt silica plate), provides the corrections. A Proportional Integral Differential (PID) closed loop controls the ISU such that telescope tracking is corrected at a rate of 5 Hz. This paper presents the technical architecture of the guiding system and performance measurements on the sky in engineering runs with WIRCam with faint stars up to magnitude 14.

The Canada-France-Hawaii Telescope (CFHT) is now operating a Wide Field Infrared Camera (WIRCam) with a 20.5' x 20.5' field of view. The camera uses a mosaic of four Rockwell HAWAII-2RG detectors enabling subsample readouts at a rate of 50Hz for guiding and fast parallel readout of 32 amplifiers per detector for science. This paper will discuss the software architecture and implementation used to optimize the scientific productivity of the instrument as well as our experience during the first semester of use.

The real-time control system for the Keck Interferometer Nuller provides the N-band fringe tracking capabilities of the instrument, as well as correcting for atmospheric dispersion in the system. There are three closed-loop servos for controlling the N-band path, as well as two K-band servos which provide open-loop control. A system of synchronized "gates" allows all N-band fringe trackers to operate simultaneously, making it possible to interleave servo corrections with data collection. Several methods of improving servo performance and maintenance of control schemes are discussed.

X-Shooter is the first 2^nd generation instrument to be installed at Paranal early 2008. It is a single target spectrograph covering in a single exposure a wide spectral range from the UV to the K' band with maximum sensitivity. Another key feature of the instrument is its fast response, obtained by making it simple and easy to operate. Compared to other big VLT instruments X-Shooter has a relatively small number of moving functions, but nevertheless the requirements on the whole instrument software are quite demanding. In order to cover the wide spectral range with high efficiency, the instrument is split into three different arms, one being cryogenically cooled. The high level coordinating software architecture provides all the facilities for parallel operation with the maximum achievable level of synchronicity. Low level X-Shooter requirements are also quite stringent, since to compensate for slit misalignments among the three arms, an active piezoelectric actuator system is envisaged. The low-level architecture, besides the typical control of single devices (like motors, sensors and lamps), handles the required real-time operations. The software integration and test is also an issue, being X-Shooter a collaborative effort among several institutes spread around Europe. The whole instrument software architecture is presented here, entering in details into its main modules such as the instrument control software, the observation software and the observing templates structure and their integration in the VLT software environment.

Lucifer VR is a virtually realized instrument that was build in order to allow improved pre-integration software tests, training of observers as well as providing educational access. Beside testing the instrument hardware in combination with e.g. a telescope simulator, software tests need to be done. A virtual instrument closes the gap between regression tests and testing the control software with the integrated instrument. Lucifer VR allows much earlier tests and reduces the amount of time needed to combine the software with the hardware. By modeling the instrument in a simulator, motion times can be calculated very easily and the position of all instrument units can be traced. Especially when using complex mechanisms like a MOS unit a virtual instrument makes software development less time consuming. Lucifer VR consists of three parts; one for handling the communication, another to simulate the hardware and finally a part to visualize the whole instrument in three dimensions.

The National Radio Astronomy Observatory (NRAO) in Green Bank was charged with replacing and enhancing the original control system on the NRAO 43-Meter (43m) telescope, for a minimum amount of labor, time and materials. The original 1960's vintage design required continuous operator presence for monitoring and control of the telescope. A fully automated, unattended operation was desired, along with better tracking performance at high speeds and reduced maintenance costs. We responded with a design based on proven industrial control technology, RTAI/Linux computers, and hardware and software adapted from the GBT and other NRAO telescopes. Commercial off-the-shelf software packages were also used in the system. We describe the overall design of the system and the decision process that led to the adoption of the various pieces of hardware and software, including the tradeoffs made between buying and building systems, and allocation of telescope functions between subsystems.

To improve operational availability (the proportion of time that a telescope is able to accomplish what a visiting observer wants at the time the observation is scheduled), response time to faults must be minimized. One way this can be accomplished is by characterizing the relationships and interdependencies between components in a control system, developing algorithms to identify the root cause of a problem, and capturing expert knowledge of a system to simplify the process of troubleshooting. Results from a prototype development are explained, along with deployment issues. Implications for the future, such as effective knowledge representation and management, and learning processes which integrate autonomous and interactive components, are discussed.

The Large Synoptic Survey Telescope (LSST) is planned to start construction in early 2009 and achieve first light in late 2012. The LSST Data Management System (DMS) has the responsibility to: 1) process the stream of raw images (15 TB/night) generated during observing to create and archive the nightly data products; 2) reprocess archived data products to incorporate pipeline improvements and generate longer-term data products; 3) provide a public interface that makes available all generated data products. The DMS must perform these duties throughout the multi-decade lifetime of the survey and its data products. It is given that computing hardware undergoes generational changes every 3 to 5 years, software engineering paradigms shift every decade, and astronomy data reduction and analysis algorithms are in constant evolution. Thus, if the useful life of the LSST Data Products is even 2 decades, the raw data will be completely re-processed at least 20 times with improved algorithms, the computing on which this is executed will be completely changed at least 4 times, and the software engineering paradigm and software architecture will completely change at least once. Managing this evolution in the DMS will require strategies in all areas of LSST Data Management, including: 1) a layered system architecture; 2) stable interfaces preserving backward compatibility; 3) plug-and-play components for pipeline construction; 4) extendable data and metadata types for catalog construction; 5) open interfaces for resource registration and access; 6) provenance and preservation mechanisms. This paper describes how we plan to employ these strategies and the expected benefits.

The paper discusses methods and strategies for designing software systems for modern observatories. The development of software continues to be a challenge for new projects, in areas ranging from budget and schedule to design and operations. Software systems can be challenging areas to plan and manage if effective methods are not undertaken early in a project. Software is itself a system, developed similarly to other, more classical systems. It may be distributed across many other systems, but it must function as a single, coordinated entity. It is process-oriented, executing a behavior consistent with its input parameters and delivering a desired outcome. It is based upon a unifying architectural concept and built around a common infrastructure. Understanding and implementing these characteristics early in the design stage allows software to develop efficiently, rather than evolving toward them in a semi-random walk.

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.

Giano is an infrared (0.9-2.5 μm) cross-dispersed echelle spectrometer designed to achieve high throughput, high resolving power, wide band coverage and high accuracy. Giano will be a common user instrument which will be permanently mounted at the Telescopio Nazionale Galileo (TNG), located at Roque de Los Muchachos Observatory (ORM), La Palma, Spain. Giano successfully concluded the development phase, and we present here some of the solutions adopted in the focal plane electronics, which take care of detector control and data acquisition and handling.

The R and D of the Chinese 4-m ever-ambitious telescope, Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST), has advanced towards a new stage, and first light is expected by the end of 2006. As one of national scientific and engineering projects the telescope will become national facility and accommodate maximum accessibility for public reach in general and for the astronomical community in particular. Thus remote or even robotic control of the telescope is put under careful exploration. With the rapid development of IT technology one of the fashions is the mobile telephone carried around by average people mainly for daily communication, and mobile notes application has become a real hit. This paper presents GSM based remote wireless application adapted to telescope control, which can be utilized for greatly enhancing LAMOST' accessibility. The novel technique has recently been developed in LAMOST control lab. Test has demonstrated successful execution of Monitor and Control (M and C) commands for LAMOST through remote wireless mobile. The hardware and software configuration with techniques involved for reliable and secure communication is outlined in this paper too.

MOIRCS (Multi-Object Infrared Camera and Spectrograph) is a new instrument for the Subaru telescope. In order to perform observations of near-infrared imaging and spectroscopy with cold slit mask, MOIRCS contains many device components, which are distributed on an Ethernet LAN. Two PCs wired to the focal plane array electronics operate two HAWAII2 detectors, respectively, and other two PCs are used for integrated control and quick data reduction, respectively. Though most of the devices (e.g., filter and grism turrets, slit exchange mechanism for spectroscopy) are controlled via RS232C interface, they are accessible from TCP/IP connection using TCP/IP to RS232C converters. Moreover, other devices are also connected to the Ethernet LAN. This network distributed structure provides flexibility of hardware configuration. We have constructed an integrated control system for such network distributed hardwares, named T-LECS (Tohoku University - Layered Electronic Control System). T-LECS has also network distributed software design, applying TCP/IP socket communication to interprocess communication. In order to help the communication between the device interfaces and the user interfaces, we defined three layers in T-LECS; an external layer for user interface applications, an internal layer for device interface applications, and a communication layer, which connects two layers above. In the communication layer, we store the data of the system to an SQL database server; they are status data, FITS header data, and also meta data such as device configuration data and FITS configuration data. We present our software system design and the database schema to manage observations of MOIRCS with Subaru.

The 1.6-meter New Solar Telescope (NST) will replace the 65 cm reflector that is currently being used at Big Bear Solar Observatory (BBSO). Some technologies new to solar telescopes, including Active Optics, will be employed in NST project. The goal of Active Optics is to correct the low frequency telescope aberrations by adjusting the figure of primary mirror and the position of the secondary mirror. The Active Optics Control Subsystem (AOCS) is part of the Telescope Control System (TCS) for NST. The AOCS will cooperate with the Wavefront Sensing Control Subsystem to correct the lower order aberrations of the telescope system. When fully developed, it will work in close-loop. The wavefront aberration information will be obtained from the wavefront sensor and corresponding corrections will be applied to the primary mirror and the secondary mirror. In this paper, the design and the implementation of the AOCS will be described in detail.

No periodical error and free of backlash are the main advantages of friction drive. So friction drive is applied in many ultra-low speed systems in the past years. With the trend that the aperture of optical telescope becomes bigger and bigger, there are some reports about friction drive employed to drive the telescopes. However friction drive also brings up challenge to control system because the inherent nonlinear characteristics of friction drive. This report describes the study on the friction drive finished in an experiment arranged by LAMOST project. It comprises three main parts. First, it introduces the experiment apparatus and presents a friction nonlinear curve to indicate the nonlinear characteristics of friction drive. Subsequently, this report illuminates the negative result that influenced by the nonlinear characteristic. Secondly, this report use nonlinear PID control algorithm to control friction drive. It achieves ultra-low speed and high precision position control. The ultra-low velocity is 0.2"/S and error is 0.032"(RMS). This report also lists some factors that influence the precision of speed. Lastly, this report gives the analysis fluctuating speed of friction drive and applies acceleration feedback to diminish this fluctuating.

The Advanced Technology Solar Telescope (ATST) is designed as the premier ground-based solar telescope. With an expected lifetime of more than 25 years, a great deal of thought has been put into designing a software control system with the flexibility to adapt to changes in software technology through the lifetime of ATST. The goal is to have a software architecture that can be readily adapted to advances in software technologies. A significant aspect of this architecture is its independence from third-party tools, particularly communications middleware. This independence is achieved through a carefully-layered design that facilitates the process of replacing one service implementation with another by separating the functional and technical infrastructures within a container/component model. The paper presents the details of how ATST implements this separation and allows the quick replacement of one service implementation with another implementation using a toolbox metaphor. The toolbox provides a consistent external interface to services and service-related data while providing an internal interface that supports dynamic replacement of one service plugin with another.

tpk is a C++ class library, layered on TCSpk and slalib that implements virtual telescope objects for generating mount and rotator position (and optionally, velocity and acceleration) demands, predicting the position of guide probes etc. in the focal plane and tip and tilt for steerable optics. These objects allocate and manage storage for the kernel context in a thread safe manner enabling a pointing kernel for a specific telescope configuration to be constructed simply by creating the necessary objects and calling their "fast", "medium" and "slow" update methods at the appropriate rates. Additional facilities include: Tracking of solar system objects using orbital elements as tabulated by the Minor Planet Center, the JPL Horizons system and the Astronomical Almanac or the for the major planets, built-in ephemeredes due to Chapront and Francou - Management of pointing models including the logging of pointing test data capable of being read into TPOINT, catalogues of pointing reference stars and pointing adjustments from handsets and guiders including the necessary digital filters - Generation of world coordinate system mappings and FITS keywords for instruments. The library can be tailored for a particular operating environment by replacing the mutex and clock classes. For "off-line" or otherwise non time-critical application the existing Posix and Windows implementations can be used.

The advantages of being able to accurately measure redshift with photometric data are of great importance for studying cosmology, large scale structure of the Universe, determination of fundamental astrophysical quantities and so on, because photometric redshifts may provide approximate distances to the enormous set of objects. At present various algorithms for photometric redshifts have been investigated. This is induced us to develop a software platform that integrates different algorithms of estimating photometric redshifts, such as color-magnitude-redshift (CMR), Support Vector Machines (SVMs), HyperZ and Artificial Neural Networks (ANNs). The requirements of the software platform, architectural issues are addressed and its framework design implemented are discussed. It provides a user-friendly interface, by which users can choose the method they like, upload their own data, and then get their needed result by clicking a mouse. This framework is flexible and extensible enough to measure photometric redshifts.

The federation of data from distributed locations, different archives and different wavelengths can lead to new discoveries. Moreover, it is an important part of functions of the Virtual Observatory. We review the technical challenges involved in this issue, and develop a system which majors in providing a robust framework to efficiently extract the data from different sources into a science-grade data for the convenient use of astronomers. The system consists of several tasks wrapped together into an integrated framework. The tasks include: the automated creation of database, the rapid query of catalogs, cross-match query and the visualization of the queried results. Especially for cross-matching service, many choices are provided for users, such as one-to-one entry, one-to-many entry, one-to-none entry, none-to-one entry. Meanwhile, the probability of cross-matching is given. In addition, users may select the attributes and the range of attributes according to their requirements. We will further improve the system in various respects according to the standards of the IVOA.

A new application framework for virtual observatory (VO) is designed for discovering unknown knowledge from thousands of astronomical catalogs which have already released and are accessible through VO services. The framework consist of two new technologies to seamlessly associate data queried from SkyNode supported databases with data mining (DM) algorithms, which either come from third-party software or are developed directly above the framework. The first one is a high level programming language, called Job Description Language (JDL), for describing jobs for data accessing and numerical computation based on web services. The second technology is a computation component standard with both local and web service invocation interface, which is named as CompuCell. It is a universal solution for integrating arbitrary third-party DM software into the framework so as to invoke them directly in JDL program. We implement a prototype with a JDL supported portal and achieve clustering algorithm in CompuCell components. We combine a series of data mining procedures with a data access procedure by programming in JDL on the portal. A scientific research, which recognizes OB associations from 2MASS catalog, is treated as a demonstration for the prototype. It confirms the feasibility of the application framework.

The Atacama Large Millimeter Array (ALMA) is an international telescope project currently under construction in the Atacama desert of Chile. It has a provision for 64 antennas of 12m each, arranged over a geographical area of a few square kilometers. Antenna control and correlated data acquisition is implemented by means of a distributed set of realtime Linux computers, each one hosting ALMA Common Software (ACS) based applications and connected to a common time base distributed by the ALMA Master Clock as a 48ms electronic pulse signal (time event). All these computers require to be time synchronized for achieving coordination between commands and data acquisition. For this purpose, the ArrayTime system presented here implements a real-time software facility that makes possible to unambiguously time-stamp each time event arriving at each computer node (distributed clock), relative to an external time source of 1Hz and in phase to the TAI second. Array time is the absolute time of each time event, and synchronization of distributed clocks is resolved by communicating the array time, via ACS services, for the next time event interrupt at least once during the operational cycle of the distributed clock. Thereafter, it is possible to schedule application tasks within a latency range of 100us by extrapolating from the last interrupt and based on the current CPU Time Stamp Counter (TSC) and the estimated frequency of the CPU clock. In the following, we present a description of the elements that constitute the ArrayTime facility.

The VST active optics software must basically provide the analysis of the image coming from the wavefront sensor (a 10×10 subpupils Shack Hartmann device) and the calculation of primary mirror forces and secondary mirror displacements to correct the intrinsic aberrations of the optical system and the ones originated for thermal or gravity reasons. The software architecture, the simulation code to validate the results and the status of work are here described.

The adapter of the VST telescope hosts many devices handled by the overall telescope control software: a probe system to select the guide star realized with motions in polar coordinates, a pickup mirror to fold the light to the image analysis and guiding cameras, a selectable reference light system and a focusing device. The algorithm to select the guide star depends on the specific geometry of the system. All these devices deeply interface with autoguiding, active optics and field rotation compensation systems. A reverse engineering approach mixed to the integration of new specific solutions has been fundamental to match the ESO commitments in terms of software re-use, in order to smoothen the integration of a new telescope designed and built by an external institute in the ESO environment. The control software architecture is here described, as well as the status of work.

One of the tightest requirements to be respected for a telescope as the VST, hosted in a one of the best astronomical sites as the ESO Paranal Observatory, is an excellent axes control, to obtain the best overall performance of the telescope that, otherwise, can be dramatically affected. The software strategy to control the VST axes (azimuth, altitude, rotator) is here described.

Active optics systems have been designed for most of the recently built medium and large telescopes. Anyway the number of working active optics systems is still relatively small and there are some differences in the various technologies and solutions. This paper describes a toolbox for active optics simulation developed in the framework of a specific project, but general enough to be useful in most of the cases. The toolbox deals with both off-line and online activities: it generates fictitious Shack-Hartmann fits images, supports different kinds of polynomials (Zernike, quasi-Zernike, normalized Zernike, minimum energy modes) to fit the wavefront data, and performs calculation of primary mirror actuator forces and secondary mirror position corrections, simulating also the usage of hexapod systems.

High precision magnetic analyzer is one of key points in technologies of Chinese space solar telescope, which is under pre-investigation. Magnetic analyzer needs a modulation component to change its polarization state. For ground-based use, usually electroptics crystal KD*P is a good option. However KD*P needs a power supply as high as thousands volts. In space environment, such a high pressure source is hardly available. Therefore we have to use an alternative, an optomechical modulator. In the modulator, the related optical components rotate precisely to realize modulation. This raises a crucial request for position accuracy and positioning times of optical components rotation. This paper describes our developing process of the electric control for the magnetic analyzer. Firstly, hardware facilities, control software design and test results as well are given. Then, some problems in manufacture and adjustment are analyzed and discussed. After overall optical, mechanical and electric tests, it shows that the accuracy of rotation position of the optical components is better than 10"(p-p) (checking with a precise 24 sides' standard); while time for rotating 90 degrees is less than 2 seconds. The results demonstrate that the magnetic analyzer has met the design requirements.

The FPGA with Avalon Bus architecture and Nios soft-core processor developed by Altera Corporation is an advanced embedded solution for control and interface systems. A CCD data acquisition system with an Ethernet terminal port based on the TCP/IP protocol is implemented in NAOC, which is composed of a piece of interface board with an Altera's FPGA, 32MB SDRAM and some other accessory devices integrated on it, and two packages of control software used in the Nios II embedded processor and the remote host PC respectively. The system is used to replace a 7200 series image acquisition card which is inserted in a control and data acquisition PC, and to download commands to an existing CCD camera and collect image data from the camera to the PC. The embedded chip in the system is a Cyclone FPGA with a configurable Nios II soft-core processor. Hardware structure of the system, configuration for the embedded soft-core processor, and peripherals of the processor in the PFGA are described. The C program run in the Nios II embedded system is built in the Nios II IDE kits and the C++ program used in the PC is developed in the Microsoft's Visual C++ environment. Some key techniques in design and implementation of the C and VC++ programs are presented, including the downloading of the camera commands, initialization of the camera, DMA control, TCP/IP communication and UDP data uploading.

We present the design and implementation of the Japanese Virtual Observatory (JVO) system. JVO is a portal site to various kinds of astronomical resources distributed all over the world. We have developed five components for constructing the portal: (1) registry, (2) data service, (3) workflow system, (4) data analysis service (5) portal GUI. Registry services are used for publishing and searching data services in the VO, and they are constructed using an OAI-PMH metadata harvesting protocol and a SOAP web service protocol so that VO standard architecture is applied. Data services are developed based on the Astronomical Data Query Language (ADQL) which is an international VO standard and an extension of the standard SQL. The toolkit for building the ADQL-based service is released to the public on the JVO web site. The toolkit also provides the protocol translation from a Simple Image Access Protocol (SIAP) to ADQL protocol, so that both the VO standard service can be constructed using our toolkit. In order to federate the distributed databases and analysis services, we have designed a workflow language which is described in XML and developed execution system of the workflow. We have succeeded to connect to a hundred of data resources of the world as of April 2006. We have applied this system to the study of QSO environment by federating a QSO database, a Subaru Suprim-Cam database, and some analysis services such a SExtractor and HyperZ web services. These experiences are described is this paper.

A high performance multicast model for the bulk data transfer mechanism in the ALMA (Atacama Large Millimeter Array) Common Software (ACS) is presented. The ALMA astronomical interferometer will consist of at least 50 12-m antennas operating at millimeter wavelength. The whole software infrastructure for ALMA is based on ACS, which is a set of application frameworks built on top of CORBA. To cope with the very strong requirements for the amount of data that needs to be transported by the software communication channels of the ALMA subsystems (a typical output data rate expected from the Correlator is of the order of 64 MB per second) and with the potential CORBA bottleneck due to parameter marshalling/de-marshalling, usage of IIOP protocol, etc., a transfer mechanism based on the ACE/TAO CORBA Audio/Video (A/V) Streaming Service has been developed. The ACS Bulk Data Transfer architecture bypasses the CORBA protocol with an out-of-bound connection for the data streams (transmitting data directly in TCP or UDP format), using at the same time CORBA for handshaking and leveraging the benefits of ACS middleware. Such a mechanism has proven to be capable of high performances, of the order of 800 Mbits per second on a 1Gbit Ethernet network. Besides a point-to-point communication model, the ACS Bulk Data Transfer provides a multicast model. Since the TCP protocol does not support multicasting and all the data must be correctly delivered to all ALMA subsystems, a distributer mechanism has been developed. This paper focuses on the ACS Bulk Data Distributer, which mimics a multicast behaviour managing data dispatching to all receivers willing to get data from the same sender.

MIRI, the Mid-InfraRed Instrument, is one of four instruments being built for the James Webb Space Telescope, and is developed jointly between an European Consortium and the US. In this paper we present a software data simulator for one of MIRI's four instruments: the Integral Field Unit (IFU) Medium Resolution Spectrometer (MIRI-MRS), the first mid-infrared IFU spectrograph, and one of the first IFUs to be used in a space mission. To give the MIRI community a preview of the properties of the MIRI-MRS data products before the telescope is operational, the Specsim tool has been developed to model, in software, the operation of the spectrometer. Specsim generates synthetic data frames approximating those which will be taken by the instrument in orbit. The program models astronomical sources and generates detector frames using the predicted and measured optical properties of the telescope and MIRI. These frames can then be used to illustrate and inform a range of operational activities, including data calibration strategies and the development and testing of the data reduction software for the MIRI-MRS. Specsim will serve as a means of communication between the many consortium members by providing a way to easily illustrate the performance of the spectrometer under different circumstances, tolerances of components and design scenarios.

The Observatorio de Sierra Nevada (OSN) is located at an altitude of 2800m at the Loma de Dilar in the Sierra Nevada mountain range, in the province of Granada, Spain. It is operated and maintained by the Instituto de Astrofisica de Andalucia (IAA-CSIC) and contains two Nasmyth telescopes with apertures of 1.5 and 0.9m and an Altazimuth telescope with an aperture of 0.6 m. Given that the quality of the images and, indeed, the performance of the instruments are influenced by weather conditions, it would appear that the existence of a weather station capable of producing accurate descriptions is an essential component of any observatory. This is particularly true, however, in our case where, given the altitude, weather conditions at certain times of the year are especially harsh. For this reason, our observatory has required the installation of a robust weather station with easily replaceable sensors which can provide accurate and reliable measures of wind, temperature and humidity. At the same time, in order to avoid a complex topology of unmanageably long wires due to the distribution of a large number of sensors around the buildings, domes telescope mirrors and instruments, it has been necessary to implement a distributed system with several independent nodes connected to a CAN bus. This system is now in operation and running automatically at the OSN and provides all the data from sensors to the observatory control systems and to internet users. This paper gives a detailed description of the SNOWS project, including the development of the weather station, the software and hardware architecture, and the use of distributed nodes with a linear serial bus. The paper also provides some results regarding the wind, temperature and humidity sensors employed at the OSN.

The LUCIFER instrument is a near infrared spectrograph/imager with MOS for the Large Binocular Telescope. Here we present the final software design, the interrelation of the software packages and the used hardware architecture. The software package is completely running under Java using intensively its Remote Method Invocation (RMI) mechanisms in a distributed system environment. The use of Java helped us to cope with a small amount of available manpower for the SW development, providing many native built-in Java methods and classes, which speed up the development process a lot. The control software will be finally installed on a Solaris OS, hosted on a Sun Fire V880 server, which results from a specific hardware constraint. For testing purposes a standard Linux environment is used. This shows another big Java advantage, the platform independency. The "First Light" of LUCIFER 1 is estimated for summer/fall 2007, following LUCIFER 2 one year later.

The Sierra Nevada Observatory (Granada, Spain) has a number of telescopes. Our study will focus on two Nasmyth telescopes with apertures of 1.5m and 0.9m and an equatorial mount. The system currently installed to control these telescopes is a 1995 centralized VME module. However, given the problems which have arisen due to the number of wires and other complications, we have decided to change this control module. We will control each telescope with a distributed control philosophy, using a serial linear communication bus between independent nodes, although all system capabilities are accessible from a central unit anywhere and at any time via internet. We have divided the tasks and have one node for alpha control, another for delta control, one for the dome, one for the focus and the central unit to interface with a pc. The nodes for alpha, delta and the dome will be used by means of FPGA's in order to efficiently sample the encoders and the control algorithms, and to generate the output for the motors and the servo. The focus will have a microcontroller, and the system is easy to expand in the event of the inclusion of more nodes. After having studied several fieldbus systems, we have opted for the CAN bus, because of its reliability and broadcasting possibilities. In this way, all the important information will be on the bus, and every node will be able to access the information at any time. This document explains the new design made in the IAA for the new consoles of control whose basic characteristics are, the distributed control, the hardware simplify, the cable remove, the safety and maintenance improve and facilitating the observation improving the interface with the user, and finally to prepare the system for the remote observation.

AMICA is a camera conceived to automatically acquire infrared astronomical images in the extreme environment of Dome C (T ~ -70 °C, p ~ 640 mbar). For this reason, hardware and software are specially designed. They must guarantee the correct execution of observing procedures, while performing a continuous monitoring of the environmental conditions, the instrument status and the observing parameters, and a real-time adjustment of them when required. All temperature-sensitive components will be placed in a thermally controlled rack. The environmental control inside it is assigned to a Programmable Logic Controller (PLC). It is responsible, in particular, for the overall system start-up. Instrument status, mainly concerning vacuum level and temperatures inside the cryostat, is directly monitored by the local cPC, which sends instructions to the PLC in case of failure, in order to start appropriate restoring procedures. All hardware components are conceived to be easily and fast replaceable. Main tasks of the AMICA Control Software (ACS) are: telescope interaction, observation management, environment control, events handling, data storing. Because of the high frame rate, typical of infrared imaging, the acquisition system has been interfaced with an independent application (STS), to perform read-out electronics control, fast data processing (co-adding from chopping raw frames), parameters checking (such as exposure time, chopping frequency, etc.), and data output. The software design has a multithreading architecture, based on the Object Oriented approach and developed for Windows OS platforms.

REMIR is the NIR camera of the automatic REM (Rapid Eye Mount) Telescope located at ESO La Silla Observatory - Chile and dedicated to monitor the afterglow of Gamma Ray Burst events. The REMIR camera is composed by a set of sub systems: the array controller, the cooling system, the temperature and the pressure monitors, the filter wheel controller, the dither wedge controller. During 2005, a complete re-writing of the REMIR software control system started in order to optimize the system performances: the new configuration will adopt a client server architecture, where a supervisor system accepts via socket the data acquisition queries from AQUA (the acquisition data suite), manages the several components of the camera and the communication with the telescope control system. Here we describe in particular the philosophy adopted to realize the general control system, the sub systems and the communication protocols.

The MPIA is leading an international consortium of institutes in building an instrument called LINC-NIRVANA, the LBT INterferometric Camera and Near-IR / Visible Adaptive INterferometer for Astronomy. LINC-NIRVANA is a Fizeau interferometer for the Large Binocular Telescope doing imaging in the near infrared (J, H, K - band). Multi-conjugated adaptive objects is used to increase sky coverage and to get diffraction limited images over a 2 arcminute field of view. The LN Common Software provides a software infrastructure common to all partners and consists of a documented collection of common patterns in control systems and of services, which implement those patterns. The heart of LCSW is an object model of controlled devices, implemented as ICE network objects. A code generator creates application from templates for these network objects.

We present the concept and design of the interaction between users and the LUCIFER Control Software Package. The necessary functionality that must be provided to a user depends on and differs greatly for the different user types (i.e., engineers and observers). While engineers want total control over every service provided by the software system, observers are typically only interested in a fault tolerant and efficient user interface that helps them to carry out their observations in the best possible way during the night. To provide the functionality engineers need, direct access to a service is necessary. This may harbor a possible threat to the instrument in the case of a faulty operation by the engineer, but is the only way to test every unit during integration and commissioning of the instrument, and for service time later on. The observer on the other hand should only have indirect access to the instrument, controlled by an instrument manager service that ensures the necessary safety checks so that no harm can be done to the instrument. Our design of the user interaction provides such an approach on a level that is transparent to any interaction component regardless of interface type (i.e., textual or graphical). Using the interface and inheritance concepts of the Java Programming Language and its tools to create graphical user interfaces, it is possible to provide the necessary level of flexibility for the different user types on one side, while ensuring maximum reusability of code on the other side.

The correction of atmospheric differential piston and instrumental flexure effects is mandatory for optimum interferometric performance of the LBT NIR interferometric imaging camera LINC-NIRVANA. The task of the Fringe and Flexure Tracking System (FFTS) is to detect and correct these effects in a real-time closed loop. On a timescale of milliseconds, image data of the order of 4K bytes has to be retrieved from the FFTS detector, analyzed, and the results have to be sent to the control system. The need for a reliable communication between several processes within a confined period of time calls for solutions with good real-time performance. We investigated two soft real-time options for the Linux platform. The design we present takes advantage of several features that follow the POSIX standard with improved real-time performance, which were implemented in the new Linux kernel (2.6.12). Several concepts, such as synchronization, shared memory, and preemptive scheduling are considered and the performance of the most time-critical parts of the FFTS software is tested.

The Fringe and Flexure Tracking System (FFTS) is designed to correct the atmospheric piston variations and the instrumental flexure during the NIR interferometric image acquisition of the LINC-NIRVANA camera at the LBT. The interferometric image quality depends on the performance of these corrections. Differential piston and flexure effects will be detected and corrected in a real-time closed loop by analyzing the PSF of a guide star at a frequency of up to several hundred Hz. A dedicated piston mirror will then be moved in a corresponding manner by a piezo actuator. The FFTS is expected to provide a residual piston of better then 0.1 λ at the central wavelength of the science band. Thus, the required correction bandwidth is 10-20 Hz as differential piston simulations of different seeing conditions indicate. Therefore, a sampling frequency of 100-200 Hz is required to correct OPD variations. The upper limit for the loop frequency is the resonance frequency of the mirror and the response function respectively. The piston mirror as the actuator and the FFTS detector as the sensor feedback are embedded in a very complex system. Many control loop aspects like sampling frequencies, delays, controller algorithm and control bandwidth have to be identified. With accurate simulations of the system the limits of atmospheric and instrumental conditions for reliable closed loops can be determined against the respective control parameters. We present strategies for the closed-loop control of the piston correction which are suitable to achieve the 0.1 λ requirement and the optimal overall imaging performance with a sufficient "all-purpose" control stability.

Big Bear Solar Observatory (BBSO) is building the 1.6 meter New Solar Telescope (NST). The Telescope Control System (TCS) of NST consists of many systems and applications and heterogeneous computer platforms. It is a critical task to design a robust, flexible and reliable - yet not over-complicated - communications for TCS. This paper describes the design and implementation of NST's communication software and protocols. The software is based on the Internet communication engine (Ice) middleware and uses eXtensible Markup Language (XML) for messaging.

We have designed and installed a new active remote observing system for the 1-m, f/15 telescope at the Tonantzintla Observatory. This remote system is operated in real-time through the Internet, allowing an observer to control the building, the telescope (pointing, guiding and focusing) and the CCD image acquisition at the main and finder telescopes from the Instituto de Astronomia headquarters in Mexico City (150 KM away). The whole system was modeled within the Unified Modeling Language (UML) and the design has proved to be versatile enough for a variety of astronomical instruments. We describe the system architecture and how different subsystems (telescope control, main telescope and finder image acquisition, weather station, videoconference, etc.) that are based on different operative system platforms (Linux, Windows, uIP) have been integrated. We present the first results of an IPv6 over IPv4 tunnel. Recent remote direct imaging and spectroscopic observations have been used to test the astronomical site. We conclude that this remote system is an excellent tool for supporting research and graduated observational astronomy programs.

This poster paper presents the analysis, the design, and a first prototype of the Optimized Slits Positioner Software, a part of the EMIR Observing Program Manager System (EOPMS). EMIR is a multi-slit near-IR spectrograph presently under development for the Gran Telescopio de Canarias (GTC). This tool represents a crucial step for the success and efficiency of multi-object spectroscopy. Complex algorithms have been implemented to help the observer in designing and validating the mask sets, both automatically and interactively, through a user-friendly interface.

The New Solar Telescope at Big Bear Solar Observatory will use a distributed system to control the telescope, dome, adaptive optics, thermal environment and instrumentation. The Telescope Pointing and Tracking Subsystem has the tasks of controlling the telescope dome and acting as a wrapper for the telescope mount software (provided by the mount manufacturer) and adding the specific control features needed for a large solar telescope. These include features for offset pointing to specific regions on the solar disk, safety interlock systems for the primary mirror, and provision for the alignment of the relatively small dome opening with the telescope optical axis.

The majority of extra-solar planets discovered to date have been found using Doppler-shift measurements obtained with the Hamilton Spectrometer at Lick Observatory and the High Resolution Echelle Spectrometer (HIRES) at Keck Observatory. Each of these spectrometers employs an integral exposure meter which enables observers to optimize exposure times so as to achieve the required signal-to-noise and to determine the photon-weighted midpoint of each science exposure (which is needed to correct the Doppler shift to the Solar System barycenter). In both of these systems, a propeller mirror located behind the spectrometer slit picks off a few percent of the light and directs it to a photo-multiplier tube (PMT) used to measure the exposure level versus time. In late 2006, the new Automated Planet Finder (APF) Telescope and APF Spectrometer are scheduled to begin operations at Lick Observatory; both will be dedicated exclusively to the search for extra-solar planets. Like the Hamilton and HIRES Spectrometers, the APF Spectrometer will employ an integral exposure meter, but one with a significantly different design. The APF exposure meter will employ a stationary pellicle located ahead of the slit to pick off 4% of the light and direct it to the guide camera. That camera will produce images typically at a 1 Hz rate, and those images will be used both for autoguiding and for computing the exposure level delivered to the spectrometer. In each guide camera image obtained during a science exposure, the time-tagged signal from the pixels that correspond to the spectrometer slit will be integrated in software to determine the current exposure level and the photon-weighted midpoint of that science exposure. We compare these two different design approaches, and describe the significant hardware and software features of each of these systems.

RTS2, or Remote Telescope System, 2nd Version, is an integrated package for remote telescope control under the Linux operating system. It is designed to run in fully autonomous mode, picking targets from a database table, storing image meta data to the database, processing images and storing their WCS coordinates in the database and offering Virtual-Observatory enabled access to them. It is currently running on various telescope setups world-wide. For control of devices from various manufacturers we developed an abstract device layer, enabling control of all possible combinations of mounts, CCDs, photometers, roof and cupola controllers. We describe the evolution of RTS2 from Python-based RTS to C and later C++ based RTS2, focusing on the problems we faced during development. The internal structure of RTS2, focusing on object layering, which is used to uniformly control various devices and provides uniform reporting layer, is also discussed.

Web-enabled user interfaces for the control and monitoring of instruments and telescopes have a checkered history. However, the remarkable interactive speed and quality of Google Maps and Google Suggests have led us, like others, to take another look at implementing services over the Web. The so-called AJAX mechanism enables simple, lightweight, efficient, and responsive interfaces in nearly any modern Web browser. We discuss methods, security, and other implementation issues for sample interfaces that include telescope monitoring, instrument control, and weather station information.

ATST control systems communicate by passing sets of attribute-value pairs between system components. Each set, or configuration, defines a required state for a component to match. To coordinate the control systems using configurations, every component must implement a consistent behavior. The ATST Controller provides a base class for components to use that implements a uniform life cycle and functional behavior for matching configurations. The ATST Controller class is one of the key elements of the ATST Common Services software framework. The Controller class accepts input configurations though a simple command interface. The class is readily extended to subclasses that may perform detailed operations based on the configuration. Alternatively, ATST Controllers may be used in hierarchical systems that delegate actions to groups of lower level controllers. The Controller provides a simple configuration life cycle to determine the state of a configuration in a component. The Controller also enforces a separation of a component's command request and the ensuing action by executing each configuration in its own thread. This implementation also allows a Controller to execute simultaneous configurations, where the synchronization and exclusion details are left to the implementing subclass.

The New Solar Telescope (NST) is an advanced solar telescope at Big Bear Solar Observatory (BBSO). It features a 1.6-m clear aperture with an off-axis Gregorian configuration. An open structure will be employed to improve the local seeing. The NST Telescope Control System (TCS) is a complex system, which provides powerful and robust control over the entire telescope system. At the same time, it needs to provide a simple and clear user interface to scientists and observers. We present an overview of the design and implementation of the TCS as a distributed system including its several subsystems such as the Telescope Pointing and Tracking Subsystem, Wavefront Sensing Subsystem etc. The communications between different subsystems are handled by the Internet Communication Engine (Ice) middleware.

This paper describes the control of two deformable mirrors (DM) and a tip tilt mirror for adaptive optics. The purpose of this experimental adaptive optics system at the University of Victoria is to prove the Woofer Tweeter concept for use in instruments for the Thirty Meter Telescope (TMT) which is currently under development. The first deformable mirror is a large stroke DM (Woofer) capable of lower frequency correction in both the temporal and spatial domains. The other DM (Tweeter) is capable of the high temporal and spatial frequency corrections of the turbulence. The response speed of the Woofer is incorporated into the Tweeter controller in order to allow for appropriate offloading from the Tweeter to the Woofer. In order to determine which Tweeter shapes must compensate for the slower Woofer and which are not coupled to the Woofer, the cross correlation of the devices is determined. The method of converting the wave front sensor (WFS) measurements to control signal error is given. The transfer functions of the controller are provided, along with rejection ratio plots, bandwidths and amplitude response to system noise.

Image-based wavefront sensing provides significant advantages over interferometric-based wavefront sensors such as optical design simplicity and stability. However, the image-based approach is computationally intensive, and therefore, applications utilizing the image-based approach gain substantial benefits using specialized high-performance computing architectures. The development and testing of these computing architectures are essential to missions such as James Webb Space Telescope (JWST), Terrestrial Planet Finder-Coronagraph (TPF-C and CorSpec), and the Spherical Primary Optical Telescope (SPOT). The algorithms implemented on these specialized computing architectures make use of numerous two-dimensional Fast Fourier Transforms (FFTs) which necessitate an all-to-all communication when applied on a distributed computational architecture. Several solutions for distributed computing are presented with an emphasis on a 64 Node cluster of digital signal processors (DSPs) and multiple DSP field programmable gate arrays (FPGAs), offering a novel application of low-diameter graph theory. Timing results and performance analysis are presented. The solutions offered could be applied to other computationally complex all-to-all communication problems.

The LSST Camera Control System (CCS) will manage the activities of the various camera subsystems and coordinate those activities with the LSST Observatory Control System (OCS). The CCS comprises a set of modules (nominally implemented in software) which are each responsible for managing one camera subsystem. Generally, a control module will be a long lived "server" process running on an embedded computer in the subsystem. Multiple control modules may run on a single computer or a module may be implemented in "firmware" on a subsystem. In any case control modules must exchange messages and status data with a master control module (MCM). The main features of this approach are: (1) control is distributed to the local subsystem level; (2) the systems follow a "Master/Slave" strategy; (3) coordination will be achieved by the exchange of messages through the interfaces between the CCS and its subsystems. The interface between the camera data acquisition system and its downstream clients is also presented.

The Large Binocular Telescope (LBT) features dual 8.4 m diameter mirrors in a common elevation-over-azimuth mount. The LBT moves in elevation on two large crescent-shaped C-rings that are supported by radial hydrostatic bearing pads located near the four corners of the rectangular azimuth frame. The azimuth frame, in turn, is supported by four hydrostatic bearing pads and uses hydrodynamic roller bearings for centering. Each axis is gear driven by four large electric motors. In addition to precision optical motor encoders, each axis is equipped with Farrand Inductosyn strip encoders which yield 0.005 arcsecond resolution. The telescope weighs 580 metric tons and is designed to track with 0.03 arcsecond or better servo precision under wind speeds as high as 24 km/hr. Though the telescope is still under construction, the Mount Control System (MCS) has been routinely exercised to achieve First Light. The authors present a description of the unique, DSP-based synchronous architecture of the MCS and its capabilities.

We present the general software design and acquisition facilities of GIANO, an ultra-stable IR echelle spectrometer optimized both for low (R ≃ 500) and high (R ≃ 50, 000) resolution, that will be mounted at Nasmyth-B focus of the Telescopio Nazionale Galileo (TNG). We describe the high-level software structure of the instrument, the user interface characteristics and the control of all subsystems. The management of GIANO sensors and controls of the mechanical movements is indeed a crucial issue that is handled by dedicated tasks. Monitoring of all these parameters is performed by means of separated processes running in background on the control workstation (PC). In this paper we will also schematically discuss the software for the instrument control, status display and setup, the quick look facility and the pipeline for data reduction.