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Hubble Space Telescope - Monitoring Science Instrument using the On-line Telemetry Archive System
Abstract
A major milestone in the effort to update the aging Hubble Space Telescope (HST) ground system was completed when HST operations were switched to the new ground system, a project called “Vision 2000 Control Center System (CCS)”, at the time of the third servicing mission in December 1999. One subsystem of CCS is the Space Telescope Engineering Data Store, the design of which is based on modern Data Warehouse technology. In fact, the Data Warehouse as implemented in the CCS Ground System that operates and monitors the Hubble Space Telescope represents the first use of a commercial Data Warehouse to manage engineering data. As of now, the process of populating the Data Warehouse with HST historical telemetry data is completed, providing access to HST engineering data for a period of over 13 years. This paper will provide hands-on experience from an end user perspective using the Data Warehouse as an HST engineering telemetry archive. Engineering Team at the Space Telescope Science Institute are using HST telemetry extensively for
· Spacecraft Anomaly resolutions · Science Instrument trending · Improve Instrument operational efficiency
with the overall idea to maximize science output of the observatory.
Keywords: Telemetry Processing, Telemetry archiving, Spacecraft Monitoring, Long-term trending, WEB-based telemetry access system, Telemetry Pipeline Processing, Data Warehousing, Hubble Space Telescope operations.
The 2.6 m VST telescope is going to be installed at Cerro Paranal (Chile) as a powerful survey instrument for the ESO VLT. It is a joint project between the INAF - Osservatorio Astronomico di Capodimonte (OAC) and ESO. OAC has been committed to design and install the telescope, software included, but after the installation and commissioning VST will be managed by ESO. Therefore in order to simplify the future maintenance of the software by ESO staff, it has been agreed to develop the VST software in the most VLT-compliant way. This constraint translates into pros & cons for OAC side, because many software utilities developed for VLT are available, but their migration to VST case requires a deep knowledge of all details, usually known to the original software developers only. In this context a reverse engineering approach, combined with the traditional software development for the VST specific subsystems, is the only solution. This paper deals both with technical aspects and software engineering design and development strategies
STScI previously used Microsoft Word and Microsoft Access, a Sybase ODBC driver, and the Adobe Acrobat PDF writer, along with a substantial amount of Visual Basic, to generate a variety of documents for the internal Space Telescope Grants Administration System (STGMS). When investigating an upgrade to Microsoft Office XP, we also began considering alternatives, and ultimately selected OpenOffice.org. Because STGMS is written principally in Java, moving to OpenOffice.org simplifies the interfaces between the main application and the document generation process. OpenOfice.org is an Open Source product, which reduces the acquisition cost. Since it provides direct JDBC access and includes a PDF generation facility, it reduces the total number of products required to operate the internal STGMS system, simplifies the build system, and opens the possibility of moving to a non-Windows platform.
We describe the experience of moving from MS Office to OpenOffice.org, and our other internal uses of OpenOffice.org in our development environment.
The Large Binocular Telescope (LBT) consists of two 8.4-meter mirrors on a common mount. This configuration provides the light gathering power equivalent to an 11.8-meter telescope and the resolving power of an 22.8-meter telescope. Due to the binocular nature of the telescope, there are unique requirements imposed on the telescope control system (TCS) to ensure the health and safety of the telescope, while also enabling observations in both independent and interferometric mode.
This poster presents the design of the TCS, from the graphical user interface (GUI) and the plotting and analysis capabilities at the highest interaction level to the low-level interfaces for the hardware. Command and control of the telescope is done primarily through a series of GUIs which communicate directly with a centralized controller or command sequencer (CSQ). The command packets are XML strings which are transferred using a customized remote procedure call (RPC) library. This customized library properly supports a multi-threaded environment and only needs to accommodate the transfer of strings.
The primary responsibilities of the CSQ are to validate incoming requests and to route the requests to the appropriate subsystems. Since a single command can blossom into a series of necessary actions which need to be assigned to a variety of the telescope subsystems (e.g., mount control, pointing control), a petri net technique is employed by the CSQ to handle the sequencing. Petri nets are well suited to model concurrent and discrete events, and therefore, are ideal for control system specification.
All system commands, variables, and ancillary information are defined in a data dictionary which enforces the concept of a single information source, allowing for a greater level of system integrity. Telescope status is organized by subsystem and maintained in a segment of network shared memory specifically designated for the subsystem. Collectively, the subsystem segments comprise a "telescope-wide shared memory" where each segment is propagated to all TCS platforms for a contemporaneous update of all the platforms. Logging and exception handling subsystems are a fundamental part of the overall system infrastructure, providing critical functionality. Finally, a telemetry subsystem allows one to customize system information to be archived for later analysis.
The Combined Array for Research in Millimeter-wave Astronomy (CARMA) will be the combination of the BIMA, OVRO, and SZA millimeter arrays. With first light scheduled for 2005, CARMA will be the first heterogeneous millimeter array, combining antennas varying from 3.5 m to 10.4 m in diameter. The controls for CARMA involve creating a uniform interface for all antennas. The antennas are grouped into five independently-controlled sub-array, which will be used for scientific observations, engineering, or maintenance. The sub-arrays are controlled by two components: the Sub-array Command Processor (SCP) and the Sub-array Tracker (SAT). While each sub-array has a dedicated SCP for handling command processing, a single SAT computes and distributes slowly varying parameters to the necessary sub-arrays. The sub-array interface uses CORBA distributed objects to physically separate the user interface from the array. This allows for stability in the core engine controlling the array while enabling flexibility in the user interface implementation.
We present the design and development process of the control software for the
A Survey Definition Tool (SDT) has been developed at the UK Astronomy Technology Centre (UK ATC) in Edinburgh.
The SDT calculates the coordinates of telescope positions needed to fill a given area of sky and automatically selects suitable guide stars from a catalogue for each position. It then splits the list of positions into chunks of suitable length and inserts them into a Science Program (XML based observation definition) which can be executed by the telescope's observation control system.
The tiling algorithm fills an area of sky row by row (in a given spherical coordinate system) with tiles, i.e. user defined patterns of telescope positions that will typically cover a contiguous rectangular area of sky. Suitable patterns depend on the detector layout of the instrument as well as on the observation and data reduction strategy.
The SDT was developed for the Infrared Deep Sky Survey (UKIDSS) at the UK Infrared Telescope (UKIRT) in Hawaii. The survey instrument, WFCAM, is currently being built at the UK ATC. The SDT can be readily modified for use with other telescopes and instruments. Its use with future instruments on the James Clerk Maxwell Telescope (JCMT), such as SCUBA2 and ACSIS (Auto-Correlation Spectrometer and Imaging System), is being considered.
The SDT is implemented in Java. To facilitate automatic guide star selection a Java class has been developed which reads locally installed binary USNO catalogue files and is compatible with the catalogue handling in ESO's JSkyCat. This makes it easy to switch to an online catalogue if small survey areas are processed for which the number of required guide stars is not too large.
The Combined Array for Research in Millimeter-wave Astronomy (CARMA) will be the combination of the BIMA, OVRO, and SZA millimeter arrays, at a new high elevation site (7200', 2200 m). With first light scheduled for 2005, CARMA will be the first heterogeneous millimeter array, combining antennas with diameters of 3.5, 6.1 and 10.4 meters.
CARMA's monitoring system (CAM), is designed to collect monitor data periodically from a set of heterogenous systems and organize these monitor points hierarchically. It allows for the collection/collation of sampled values from arbitrary monitor points and the storage of such monitor point values in files and databases. Monitor points may be mapped to multiple hierarchies, for example, physical hierarchies like antennas, receivers, and drives, or logical hierarchies like sub-arrays and antennas.
The monitor system was designed to accommodate monitor points associated with state machines, physical quantities (such as voltages), complex quantities (such as phases) and logical quantities like process health. It is also designed to help identify and isolate problems quickly, especially during integration at the new high site.
Keywords: Interferometry, radio antenna, monitor system, telemetry.
The National Radio Astronomy Observatory has undertaken an ambitious project that is intended to control our 100m primary Gregorian telescope, the Green Bank Telescope (GBT), at frequencies up to 115Ghz. The Precision Telescope Control System (PTCS) is being developed in order to make the improvements in telescope monitor and control which are necessary for high frequency observations described in 'The GBT Precision Telescope Control System' presentation in this conference. A key component of the PTCS is the Engineering Measurement System (EMS), a software package whose role is to provide a prototyping environment to experiment with a variety of different measurement and processing strategies. The EMS implements algorithms as signal flow graphs, uses Matlab for standard algorithms and visualization, and uses ODBC (Open Database Connectivity) and databases for organizing pertinent data. We will present an overview of the EMS system, along with it's results as to date, as well as its possible future applications.
UKIRT and JCMT are traditional ground based facilities that have shifted to a model of queue-based flexible scheduling in which applicants for time can have their observations carried out without ever coming to the telescope. We have developed a comprehensive web-based feedback system that provides a communication gateway between PIs, observers and staff. This feedback system is completely self-maintaining thanks to its close integration with other observatory systems.
WFCAM is the new wide field camera for UK Infrared Telescope under construction at the UK Astronomy Technology Centre. The instrument is an unusual design for UKIRT, not least because of its placement between the primary and secondary mirrors. The software systems have introduced several departures from standard UKIRT instruments including the use of real-time Linux systems, multi channel data handling and a design capable of semi-autonomous observing for survey fields.
This paper gives an overview of the new components in the WFCAM software system, in particular the re-use of the Ultracam software for both IR and visible (guide-star) camera control. The design choices made to facilitate handling the expected data rates (~100GB/night) are discussed.
The high data rate of next-generation radio-telescopes requires non-interactive data processing, which requires a formal, precise description of an astronomical observation. We have developed a Proposal Submission Tool (PST), which captures critical information at the earliest possible stage of the observational process, facilitating down-stream data quality control. Our PST is similar in design to traditional business workflow-management systems, and so we built it as an Enterprise JavaBeans (EJB) web application.
The NOAO extremely wide-field infra-red mosaic (NEWFIRM) camera is being built to satisfy the survey science requirements on the KPNO Mayall 4m and CTIO Blanco 4m in an era of 8m+ aperture telescopes. Rather than re-invent the wheel, the software system to control the instrument has taken existing software packages (OPC = other people's code) and re-used what is appropriate. The result is an end-to-end observation control system using technology components from DRAMA, ORAC, observing tools, GWC, existing in-house motor controllers and new developments like the MONSOON pixel server. Integrating these diverse software systems into a maintainable and configurable whole is the underlying challenge.
The Allen Telescope Array (ATA) will use off the shelf Java microcontrollers and Java friendly command and control computers. Current development at Hat Creek, CA utilizes a mixture of Java and Jython to control individual array elements. Jython has been selected as the scripting language for production operations, such as sending commands to steer the array between source and calibrators and to handle the high level coordination of the radio astronomy imaging system. This poster describes the overall framework for handling scripts, and managing the correlator and imaging system from an observer's point of view.
Upcoming Space Science and Earth Science missions face many of the same information technology hurdles: the need to dramatically increase onboard automation in order to both effectively handle an exponentially increasing volume of scientific data and to successfully meet dynamic, opportunistic scientific goals and objectives. A critical component of increasing spacecraft autonomy is to provide an as-yet-unrealized ability for spacecraft to perform opportunistic science and in-situ management of scientific activities. The Science Goal Monitor (SGM) system, being developed at NASA Goddard Space Flight Center, enables scientists to specify what to look for and how to react in descriptive rather than technical terms. Then the system monitors streams of science data to identify occurrences of the key events previously specified by the scientist. When an event occurs, the system autonomously coordinates the execution of the scientist's desired reactions between different observatories or satellites. The system is being designed to be adaptable to many different types of phenomena. Investigators will no longer have to rely on after-the-fact data analysis to determine what happened. The information can be used to rapidly respond to fast temporal events such as gamma ray bursts or hazardous events such as forest fires.
We have recently completed a prototype demonstration test with SGM using NASA’s Earth Observing-1 (EO-1) satellite and Earth Observing Systems’ Aqua/Terra spacecrafts’ MODIS instrument. In the prototype demonstration, SGM serves both as a science analyzer and a multi-mission coordinator. SGM monitored the daily list of active priority fires from the Remote Sensing Applications Center in Utah, and when a fire was identified in a scientist's specified region of interest, SGM analyzed the recent history of the fire from the MODIS Rapid Fire data in that area to isolate the latest center of activity, and then coordinated with the EO-1 planning systems to request and monitor a high-priority high-resolution image from EO-1. SGM's web-based monitor also provided the user with a live monitor of the status of his/her image request and automatically linked to the new EO-1 image when it became available. The SGM coordination and analysis provided new data to the US Forestry Service within 48 hours, compared to a typical lead time of up to 14 days for preplanned observations.
This specific science demonstration of monitoring a known active fire is relatively simple, but it shows the promise of coordinating data from different sources, analyzing the data for a scientifically relevant event, autonomously updating and rapidly obtaining a follow-on image
The SGM project applies the emerging efforts to perform goal oriented onboard scheduling. It is a proof-of-concept prototype to determine if we can effectively and efficiently obtain reliable and relevant data from scientists to make science driven scheduling changes and to measure that effectiveness.
The Observatorio Astron\'omico Nacional (OAN) is building a 40m radiotelescope in its facilities in Yebes (Spain) which will be delivered by April 2004. The servosystem control will be controlled by an ACU (Antenna Control Unit), a real time computer running VxWorks which will be controlled from a remote computer (RCC) or from a local computer (LCC) which will act as console.
We present the tools we have chosen to develop and use the control system for the RCC and the criteria followed for the choices we made. We also present a preliminary design of the control system on which we are currently working. The RCC will run a server which communicates with the ACU using sockets and with the clients, receivers and backends using OmniOrb, a free implementation of CORBA. Clients running Python will allow the users to control the antenna from any host connected to a LAN or a secure Internet connection.
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