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M.A. Albrecht, E. Angeloni, A. Brighton, J. Girvan, F.
Sogni, A.J. Wicenec, H. Ziaeepour (ESO)
The ESO Very Large Telescope (VLT) will deliver a
Science Archive of astronomical observations well
exceeding the 100 Terabytes mark already within its
first five years of operations.
In order to safely store and subsequently maximize the
scientific return of these data, ESO is undertaking
the design and development of both On-Line and Off-
Line Archive Facilities. The main objective of these
facilities is to provide the infrastructure needed to
offer the Science Archive as an additional instrument
of the VLT. The main capabilities of the system will
be a) handling of very large data volume, b) routine
computer aided feature extraction from raw data, c)
data mining environment on both data and extracted
parameters and d) an Archive Research Programme to
support user defined projects.
This talk reviews the current planning and development
state of the VLT Science Archive project.
R. Albrecht (ESO/ESA/ST-ECF), R. West (ESO), C. Madsen (ESO)
This educational programme was organised in a collaboration between ESO,
the European Association for Astronomy Education (EAAE)and the European
Union (EU) during the 4th European Week for Scientific and
Technological Culture. Asronomy on-line brings together thousands of
students from all over Europe and other continents. Learning to use the
vast resources of tomorrow's communication technology, they also
experience the excitement of real-time scientific adventure and the
virtues of international collaboration. The central web site is hosted by
ESO, and there are satellite sites in all participating countries.
Astronomy on-line features an electronic newspaper which reports
on current astronomical events and provides hotlinks to appropriate
sites. The "Marketplace" provides a gateway to collaborative projects,
astronomical data and software, and to professional astronomers in the
different participating countries who have agreed to support the project.
A. Antunes (HSTX/GSFC), P. Hilton (Hughes/ISAS), A.
Saunders (GSFC)
The next generation of Mission Scheduling software
will be cheaper, easier to customize for a mission,
and faster than current planning systems. TAKO
("Timeline Assembler, Keyword Oriented", or in
Japanese, "octopus") is our in-progress suite of
software that takes database input and produces
mission timelines. Our approach uses openly available
hardware, software, and compilers, and applies current
scheduling and N-body methods to reduce the scope of
the problem. A flexible set of keywords lets the user
define mission-wide and individual target constraints,
and alter them on the fly. Our goal is that TAKO will
be easily adapted for many missions, and will be
usable with a minimum of training. The especially
pertinent deadline of Astro-E's launch motivates us to
convert theory into software within 2 years. The
design choices, methods for reducing the data and
providing flexibility, and steps to get TAKO up and
running for any mission are discussed herein.
K. Banse, M. Albrecht (ESO)
The latest version of On-line Midas as used for ESO's
Dataflow System will be shown. The Archive group will
demonstrate SKYCAT, the catalog display tool which is
based on ESO's Real Time Display (RTD).
P.S. Also, the 96NOV Midas CD-ROM should be ready.
Invited talk
D. Barnes (University of Melbourne), L. Staveley-
Smith, T. Ye, T. Oosterloo (Australia Telescope
National Facility (ATNF))
We present algorithms and their implementation details
for the Australia Telescope National Facility (ATNF)
Parkes Multibeam Software. The new thirteen-beam
Parkes 21 cm Multibeam Receiver is being used for the
neutral hydrogen (HI) Parkes All Sky Survey (HIPASS).
This survey will search the entire southern sky for
neutral hydrogen in the redshift range -1200 km/s to
+12600 km/s; with a limiting column density of
approximately 5 x 10^{17} atoms per square centimetre.
Observations for the survey began late in February,
1997, and will continue through to the year 2000.
A complete reduction package for the HIPASS survey
data has been developed, based on the AIPS++ library.
The major software component is realtime, and uses
advanced inter-process communication coupled to a
graphical user interface (GUI), provided by AIPS++, to
apply bandpass removal, flux calibration, velocity
frame conversion and spectral smoothing to 26 spectra
of 1024 channels each, every five seconds. AIPS++
connections have been added to ATNF-developed
visualization software to provide on-line visual
monitoring of the data quality. The non-realtime
component of the software is responsible for gridding
the spectra into position-velocity cubes; typically
200000 spectra are gridded into an 8 x 8 degree cube.
A. Baruffolo, L. Benacchio (Astronomical Observatory
of Padova)
Astronomical catalogues containing from million up to
hundreds million records (e.g. Tycho, GSC-I, USNO-A
1.0) are becoming commonplace. While they are of
fundamental importance to support operations of
current and future large telescopes and space
missions, they appear also as powerful research tools
for galactic and extragalactic astronomy.
Since even larger catalogues will be released in a few
years (e.g. the GSC-II), researchers are faced with
the problem of accessing these databases in a general
but efficient manner, in order to be able to fully
exploit their scientific content.
Traditional database technologies (i.e. relational
DBMSs) have proven to be inadequate for this task.
Segmentation of catalogues in a catalogue-specific
file structure accessed by a set of programs provide
fast access but only limited query capabilities. Other
approaches, based on new access technologies, must
thus be explored.
In this paper we describe the results of our pilot
project aimed at assessing the feasibility of
employing Object-Relational DBMSs for the management
of large astronomical catalogues. In particular we
will show that the database query language can be
extended with astronomical functionalities and to
support typical astronomical queries. Further, access
methods based on spatial data structures can be
employed to speed up the execution of queries
containing astronomical predicates.
U. Becciani, V. Antonuccio-Delogu (Obs. Catania), G.
Erbacci (CINECA), R. Ansaloni (Silicon Graphics
Italy), M. Gambera (Obs. Catania), A. Pagliaro (Inst.
Astr. Catania)
During the last 3 years we have developed an N-Body
code to study the origin and the evolution of the
Large Scale Structure of the Universe (Becciani et al.
1996, 1997). The code, based on the Barnes-Hut tree
algorithm, has been developed under the CRAFT
environment to share work and data among the PEs
involved in the run. The main purpose of this work was
the study of the optimal data distribution in the T3D
memory, and a strategy for the Dynamic Load Balance
in order to obtain good performances when runnig the
simulation with more than 10 million particles. To
maximize the number of particles per second, updated
at each step, we studied the optimal data distribution
and the criterion to choose the PE executing the force
computing phase and to reduce the load unbalancing.
The results of our tests show that the step duration
depends on two main factors: the data locality and the
T3D network contention. Increasing data locality we
are able to minimize the step duration. In a very
large simulation, due to network contention, an
unbalanced load arises. The DLB consists in
implementing an automatic structure: each PE executes
the force compute phase only for a fixed portion N of
all the bodies residing in the local memory. The
computation of all the remaining bodies is shared
among all the PEs. The obtained results show that,
fixing the PEs and the particles number, the same N
value gives the best performance both in uniform and
clustered condition. This means that it's possible to
fix this quantity which can be usefully adopted during
the running time without introducing any significant
overhead to obtain a good Dynamic Load Balance.
L. Benacchio, M. Brolis (Padova Astronomical
Observatory), I. Saviane (Padova Department of
Astronomy)
A project is being carried on at the Padova
Astronomical Observatory, with the partnership of the
Italian Telecom, whose aim is to supply high quality
multimedia educational material and tools to public
schools (14-18 teen) via the Internet. A WWW server
has been set up, and in the early experimental phase,
a number of schools in the city area will be connected
to the Observatory and hence to the Internet. Teachers
and students will use it for the annual course
(1997/98)in astronomy.
Our purpose is to remove a lack in the Astronomical
WWW sites currently active, i.e., by providing a
carefully designed server which will deliver reliable
information in a structured way and, at the same time,
take full advantage of the medium. Apparently there
are no sites devoted to the explanation of the basic
astronomy and astrophysics, at the middle school
level.
Our educational approach is based on the so-called
Karplus cycle, that is: introduction of new concepts
by means of proposed experiments, discussion and
selection of the discovered laws and 'correct'
explanation of the observations and application to new
situations. To avoid the subject will try to `fit`
the new knowledge into his/her already existing wrong
schemes, a preliminary phase for the removal of
existing misconceptions is present. In turn, the
knowledge is introduced according to a hierarchical
order of concepts.
The medium involved allows the full exploitation of
this approach, since it permits direct experimentation
by means of animation, java applets, and personalized
answers to the proposed questions. Also, automatic
tests and evaluations can be straightforwardly
implemented. In this respect, it has a clear advantage
over the traditional static book. Finally, the user
can choose his/her own pace and path through the
material offered.
We also propose a number of hands-on activities which
extend and reinforce the concepts, and which require
the presence of the teacher as an active guide.
M. Bly, R. Warren-Smith (Rutherford Appleton
Laboratory)
We will demonstrate the latest Starlink applications
which will be available on the late summer Starlink
CD-ROM release. The highlights include FIGARO with
handling of error data, the GAIA GUI , an enhanced
CURSA (catalogue access) and FIGARO running from the
IRAF CL. Applications using the NDF data library will
be able to work with non-NDF (eg IRAF) data formats
using on-the-fly data conversion.
The demo needs:
SUN Ultra model 140 workstation or higher,
with 8-bit colour TGX graphics (or equivalent)
128Mb memory
4Gb disk (2Gb to be available for software and data)
20-inch colour display
4x or better CD-ROM drive
Solaris 2.5 operating system with CDE (Common Desktop
Environment)
Sparc Compiler 4.2: Fortran 77, C and C++
Internet connection if available.
A.M. Chavan (ESO), G. Giannone (Serco), D. Silva
(ESO), T. Krueger, G. Miller (STScI)
A key challenge for ESO's Very Large Telescope (VLT)
will be responding to changing observing conditions in
order to maximize the scientific productivity of the
observatory. For queued observations, the nightly
scheduling will be performed by staff astronomers
using an Operational Toolkit. This toolkit consists
of a Medium Term Scheduler (MTS) and a Short Term
Scheduler (STS) both integrated and accessible through
a Graphical User Interface (GUI). The Medium Term
Scheduler, developed by ESO, will be used to create
candidate lists of observations based on different
scheduling criteria. There may be different candidate
lists based on "seeing", or priority, or any other
criteria that is selected by the staff astronomer. A
MTS candidate list is then selected and supplied to
the Short Term Scheduler for detailed nightly
scheduling. The STS uses the Spike scheduling engine,
which was originally developed by STScI for use on the
Hubble Space Telescope.
Invited talk:
C. Christian
I will discuss various information technology methods
being applied to science education and public
information. Of interest to the group at STScI and our
collaborators is how science data can be mediated to
the non-specialist client/user. In addition, I will
draw attention to interactive and/or multimedia tools
being used in astrophysics that may be useful, with
modification, for educational purposes. In some cases,
straightforward design decisions early on can improve
the wide applicability of the interactive tool.
N. Christlieb (Hamburg Obs.), G. Graeshoff (MPI
History of Science, Berlin / Univ. Hamburg), A. Nelke,
A. Schlemminger (Univ. Hamburg), L. Wisotzki (Hamburg
Obs.)
We present methods for automatic one-dimensional
classification of digitized objective prism spectra
developed in the course of the Hamburg/ESO Survey
(HES) for bright QSOs. The HES covers about 10,000
deg2 in the southern extragalactic sky, yielding
several million usable spectra in the range 12 <- B <-
17. The resolution of the HES spectra is ~ 15A at Hg,
permitting to detect the strongest stellar absorption
features.
Our astronomical aims are:
Ґ Construction of complete samples of quasar
candidates by identification of objects that do not
have stellar absorption patterns, via classification
with the Bayes rule plus a reject option.
Ґ Construction of complete samples of rare stellar
objects, e.g. White Dwarfs, horizontal branch A-
stars, or extremely metal poor halo stars. Here a
minimum cost rule is used.
Ґ "Simple" classification of all HES spectra with the
Bayes rule, e.g. to provide a data basis for cross-
identification with surveys in other wavelength
ranges.
The feature space used for classification consists of
equivalent widths of stellar absorption features.
We report on the discovery of the extremely metal poor
halo star HE 2319-0852, [Fe/H]=-3.5±0.5, which was
discovered in a test survey for these objects on a few
of our plates using simulated spectra as learning
sample.
M. Conroy, E. Mandel, J. Roll (SAO)
Over the past few years there has been a movement
within astronomical software towards "Open Systems".
This activity has resulted in the ability of
individual projects or users to build customized
processing systems from a variety of existing
components. We will present examples of user
customizable systems that can be built from existing
systems where the only requirements on the components
are:
a) Use of a common parameter interface library.
b) Use of FITS as the input/output file format.
c) Unix + X-windows environment
With these three minimal assumptions it is possible to
build a customized image-display driven data analysis
system as well as automated data reduction pipelines.
T. Cornwell, B. Glendenning (NRAO), J. Noordam (NFRA)
AIPS++ is a package for radio-astronomical data
reduction now under development by a consortium of
radio observatories. It is currently in beta release
and it expected to be publicly released in late 1997.
Description of demo:
We will demonstrate the beta version of AIPS++. This
will consist of a demonstration by an AIPS++ Project
Member at regularly scheduled times. In addition, we
will make the system available for use by others.
R.M. Crutcher, R.L. Plante, and P. Rajlich (National
Computational Science Alliance/Univ. of IL)
We present two new applications that engage the
network as a tool for astronomical research and/or
education. The first is a VRML (virtual reality
modeling language) server which allows users over the
Web to interactively create three-dimensional (3D)
visualizations of FITS images contained in the NCSA
Astronomy Digital Image Library (ADIL). The server's
Web interface allows users to select images from the
ADIL, fill in processing parameters, and create
renderings featuring isosurfaces, slices, contours,
and annotations; the often extensive computations are
carried out on an NCSA SGI supercomputer server
without the user having an individual account on the
system. The user can then download the 3D
visualizations as VRML files, which may be rotated and
manipulated locally on virtually any class of
computer. The second application is the ADILBrowser,
a part of the NCSA Horizon Image Data Browser Java
package. ADILBrowser allows a group of participants
to browse images from the ADIL within a collaborative
session. The collaborative environment is provided by
the NCSA Habanero package which includes text and
audio chat tools and a white board. The ADILBrowser
is just an example of a collaborative tool that can be
built with the Horizon and Habanero packages. The
classes provided by these packages can be assembled to
create custom collaborative applications that
visualize data either from local disk or from anywhere
on the network.
S. Doe, A. Siemiginowska, M. Ljungberg, W. Joye (SAO)
The AXAF mission will provide X-ray data with
unprecedented spatial and spectral resolution.
Because of the high quality of these data, the AXAF
Science Center will provide a new data analysis system
- part of which includes a new fitting application.
Our intent is enable users to do fitting that is too
awkward with or beyond the scope of existing
astronomical fitting software. Our main goals are:
1) to take advantage of the full capabilities of the
AXAF, we intend to provide a more sophisticated
modeling capability (i.e., models that are f(x,y,E,t),
models to simulate the response of AXAF instruments,
and models that enable "joint-mode" fitting, i.e.,
combined spatial-spectral or spectral-temporal
fitting); and 2) to provide users with a wide variety
of models, optimization methods, and fit statistics.
In this paper, we discuss the use of an object-
oriented approach in our implementation, the current
features of the fitting application, and the features
scheduled to be added in the coming year of
development. Current features include: an
interactive, command-line interface; a modeling
language, which allows users to build models from
arithmetic combinations of base functions; a suite of
optimization and fit statistics; the ability to
perform fits to multiple data sets simultaneously;
and, an interface with SM and SAOtng to plot or image
data, models, and/or residuals from a fit. We
currently provide a modeling capability in one or two
dimensions, and have recently made an effort to
perform spectral fitting in a manner similar to XSPEC.
We also allow users to dynamically link the fitting
application to algorithms written by users. Our goals
for the coming year include: incorporating the XSPEC
model library as a subset of models available in the
application; enabling "joint-mode" analysis; and
adding support for new algorithms.
G. Eichhorn, A. Accomazzi, C.S. Grant, M.J. Kurtz,
S.S. Murray (SAO)
The ADS abstract service at:
http://adswww.harvard.edu
has been updated
considerably in the last year. New capabilities in
the search engine include searching for multi-word
phrases and searching for various logical combinations
of search terms. Through optimization of the custom
built search software, the search times were decreased
by a factor of 4 in the last year.
The WWW interface now uses WWW cookies to store and
retrieve individual user preferences. This allows our
users to set preferences for printing, accessing
mirror sites, fonts, colors, etc. Information about
most recently accessed references allows customized
retrieval of the most recent unread volume of selected
journals. The information stored in these preferences
is kept completely confidential and is not used for
any other purposes.
Two mirror sites (at the CDS in Strasbourg, France and
at NAO in Tokyo, Japan) provide faster access for our
European and Asian users.
To include new information in the ADS as fast as
possible, new indexing and search software was
developed to allow updating the index data files
within minutes of receipt of time critical information
(e.g., IAU Circulars which report on supernova and
comet discoveries).
The ADS is currently used by over 10,000 users per
month, which retrieve over 4.5 million references and
over 250,000 full article pages each month.
Invited talk:
J.R. Fisher (NRAO)
The Green Bank Telescope Monitor and Control software
group adopted object-oriented design techniques as
implemented in C++. The experience has been generally
positive, but there certainly have been many lessons
learned in the process. The long analysis phase of
the OO approach has lead to a fairly coherent software
system and a lot of module (class) reuse. Many
devices (front-ends, spectrometers, LO's, etc.) share
the same software structure, and implementing new
devices in the latter part of the project has been
relatively easy, as is to be hoped with an OO design.
One disadvantage of a long design phase is that it is
hard to evaluate progress and to have much sense for
how the design satisfies the real user needs. In
retrospect, the project might have been divided into
smaller units with tangible products at early and mid
stages of the project. The OO process is only as good
at the requirement specifications, and the process has
had to deal with continually emerging requirements all
though the analysis, design, and implementation
phases. Changes and fixes to core software modules
have not been too painful, but they do require a
robust software version control system. Large and
medium scale test of the system in the midst of the
implementation phase has required quite a bit of time
and coordination effort. This has tended to inhibit
progress evaluations.
C. Gabriel (ESA-SSD)
The ISOPHOT Interactive Analysis system, a calibration
and scientific analysis tool for the ISOPHOT
instrument on board ESA's Infrared Space Observatory
(ISO), has been further developed while ISO is under
operations.
After 18 months of ISO operations considerable
experience has been achieved by the use of PIA, which
led to several new features in the package. This
experience has been achieved not only by the ISOPHOT
Instrument Dedicated Team in its tasks of e.g.
calibration, instrument performance check and
refinement of analysis techniques, but also by a large
number of ISOPHOT observers in around 100 astronomical
institutes all over the world. PIA is distributed
freely since longer than one year to all astronomers
wishing to use it for ISOPHOT data reduction and
analysis. The feedback from the different users is
reflected not only in the extension of the analysis
capabilities but also on a more friendly graphical
interface, a better documentation, an easier
installation. So became PIA not only a very powerful
calibration tool but also the software tool of choice
for the scientific analysis of ISOPHOT data.
In this paper we will concentrate on some of the PIA
enhancements, by the scientific analysis, by the
documentation and by the related general service to
the astronomical community.
K. Gamiel (National Computational Science
Alliance/Univ. of IL)
The NCSA Pizazz SDK is an information retrieval
communications toolkit that includes code and
applications for for easily integrating existing
database systems into a globally accessible, open
standards-based system. The toolkit includes a TCP-
based server and information retrieval protocol engine
that handles all network communication between client
and server. The server is designed as a drop-in
application, extending the functionality of legacy
database systems and creating a global infrastructure
of astronomical database resources. The toolkit uses
the Z39.50 information retrieval protocol.
M. Giuliano (STScI)
Operations of the Hubble Space Telescope (HST) require
the creation of stable and efficient observation
schedules in an environment where inputs to the plan
can change daily. Operations must allow observers to
adjust observation parameters after submitting the
proposal. PIs must also be informed well in advance
the approximate date of an observation so they can
plan for coordinated observations and data analysis.
Scheduling is complicated due to ongoing changes in
the HST operational parameters and because the precise
ephemeris for HST is not known in advance. Given these
constraints, it is not possible to create a single
static schedule of observations. Instead scheduling
should be considered an ongoing process which creates
and refines schedules as required. Unlike other
applications of replanning, the HST problem places a
premium on ensuring that a replan minimally disturbs
the existing plan. A process and architecture is
presented which achieves these goals by dividing
scheduling into long term and short term components.
The long term scheduler, the main focus of this paper,
provides approximate 4-8 week plan windows for
observations. A plan window is a subset of an
observation's constraint windows, and represents a
best effort commitment to schedule in the window. The
long range planner ensures plan stability, balances
resources, and provides the short term scheduler with
the proper mixture of visits to create week long
schedules. The short term scheduler builds efficient
week long observation schedules by selecting
observations who have plan windows open within the
week.
The long term scheduler as implemented within the
Spike software system provides support for achieving
stable observations schedules. Spike models the
planning process as a function which takes as input a
previous plan, a set of proposals, and some search
criteria and produces as output a new plan. Stability
is ensured by using the input plan to guide the
creation of a new plan. Through this mechanism Spike
can handle instabilities such as changed observation
specifications, out of date observation products, and
errors in loading observation specifications. Special
routines are provided for planning and ensuring
stability for observations linked by timing
requirements (e.g. Observation 2 after observation 1
by 6-8 days). Spike provides a combination heuristic
and stochastic search engine with user defined weights
for finding near optimal plans.
Suggested presentation: Demo
R. Gupta, R.K. Gulati (IUCAA), H.P. Singh (University
of Delhi)
Recently, Artificial Neural Networks (ANNs) have been
proved to be a very efficient technique for stellar
spectral classification in spectral regions of UV,
Optical and IR. Various groups including ours have
used this technique with the main aim to evolve an
automated procedure for use with large upcoming
stellar spectral libraries which will be the major
outcome of several ongoing surveys being undertaken at
many astronomical observatories. In an attempt to
explore newer areas of applications, we have extended
this technique to obtain stellar atmospheric parameter
Teff; determination of a third dimension of
classification from UV data i.e. color excess E(B-V)
and applying Principal Component Analysis (PCA) as a
pre-processor before using the ANN on spectral data.
In the application of stellar atmospheric effective
temperature, we present the first ever attempt to
obtain Teff for dwarf stars by ANN technique and
obtain results comparable to earlier attempts by
other statistical techniques. In the second
application, we show that ANNs can extract a third
dimension of spectral classification viz. color excess
E(B-V) apart from already established spectro-
luminosity classification. Finally, we have used PCA
prior to applying ANN on our first results on Optical
spectra and improved the efficiencies for
classification.
Description of computer demo
It is proposed that in the demo session, the three new
applications will be shown on a suitable computer
platform (UNIX based SUN or DEC type workstation
having Mathematica and SM i.e. Super Mongo for
plotting the graphs etc. with telnet/ftp options for
downloading the programs are requested to be made
available at the conference venue for this purpose).
Though it may not be possible to run the training
sessions during the limited period of the ADASS
conference, the demo will amply prove the performance
of ANNs in the three new areas mentioned in the
abstract above by running the test sessions and
showing graphically the classification accuracies.
R. Gupta, R.K. Gulati (IUCAA), H.P. Singh (University
of Delhi)
Recently, Artificial Neural Networks (ANNs) have been
proved to be a very efficient technique for stellar
spectral classification in spectral regions of UV,
Optical and IR. Various groups including ours have
used this technique with the main aim to evolve an
automated procedure for use with large upcoming
stellar spectral libraries which will be the major
outcome of several ongoing surveys being undertaken at
many astronomical observatories. In an attempt to
explore newer areas of applications, we have extended
this technique to obtain stellar atmospheric parameter
Teff; determination of a third dimension of
classification from UV data i.e. color excess E(B-V)
and applying Principal Component Analysis (PCA) as a
pre-processor before using the ANN on spectral data.
In the application of stellar atmospheric effective
temperature, we present the first ever attempt to
obtain Teff for dwarf stars by ANN technique and
obtain results comparable to earlier attempts by
other statistical techniques. In the second
application, we show that ANNs can extract a third
dimension of spectral classification viz. color excess
E(B-V) apart from already established spectro-
luminosity classification. Finally, we have used PCA
prior to applying ANN on our first results on Optical
spectra and improved the efficiencies for
classification.
2. SPECIFIC DESCRIPTION OF SUGGESTED COMPUTER DEMO
It is proposed that in the demo session, the
three new applications
will be shown on a suitable computer platform
(UNIX based SUN
or DEC type workstation having Mathematica and
SM i.e. Super
Mongo for plotting the graphs etc. with
telnet/ftp options for
downloading the programs are requested to be
made available at
the conference venue for this purpose). Though
it may not be
possible to run the training sessions during
the limited period
of the ADASS conference, the demo will amply
prove the performance
of ANNs in the three new areas mentioned in
the abstract above
by running the test sessions and showing
graphically the classification
accuracies.
P. Hilton (Hughes/ISAS) and A. Antunes (HSTX/GSFC)
The ASCA X-ray satellite mission involves scientists
from Japan, America, and Europe. Each year more than
400 targets are observed by ASCA. The process starts
with the electronic submission of a proposal and ends
with the delivery of a data tape. A successful
observation depends on organization within the
operations team and efficient communication between
the operations team and the observers. The methods
used for proposals, scheduling, coordinating
observations, quick-look plots, and data delivery are
presented.
G. Hunt (NRAO)
The National Radio Astronomy Observatory (NRAO) has
facilities at 17 different locations scattered
throughout the USA. These vary in size from the major
laboratories occupied by research and support staff to
the ten individual antennas of the Very Long Baseline
Array. As is typical in astronomy, many sites are in
remote locations, which are not well served with
modern communication capabilities. Until 1996, the
NRAO's internal network was achieved via the Internet;
most sites simply had a local port to the Internet and
the traffic was routed tortuously to the other
locations. The burgeoning demand for Internet
bandwidth was (and still is) growing faster than the
services could be enhanced, and this led to
intolerably slow response times and unacceptably low
achieved data rates. To solve this problem, the NRAO
acquired a frame relay intranet to connect ten of its
locations. The service is provided under the federal
FTS2000 contract by AT&T. The operating cost is
approximately the same as the multiple Internet
connections, but with vastly improved throughput and
reliability.
Suggested presentation: Demo
W. Joye (SAO)
SAOtng is a new version of the popular SAOimage
display program. It is a superset of the ximtool
program developed at NOAO for IRAF and as such,
utilizes the NOAO widget server (included in this
package). It also incorporates the X Public Access
mechanism to allow external processes to access and
control its data, GUI functions, and algorithms.
SAOtng supports direct display of IRAF images and FITS
images (and easily can support other file formats),
multiple frame buffers, region/cursor manipulation,
several scale algorithms, many colormaps, and easy
communication with external analysis tasks. It is
highly configurable and extensible to meet the
evolving needs of the astronomical community.
The past decade has witnessed an explosion of
astronomical software development. Many talented
individuals have made great efforts to develop
libraries, programs, and analysis systems that serve
the needs of their projects and the community at
large. As a result, computer-aided astronomical
research is vastly more sophisticated than it was even
a few years ago.
One of the most striking features of this software
explosion, considered as a whole, is the tremendous
overlap in its functionality and its target audience.
Why do we continually re-invent the astronomical
software wheel? Why is it so difficult to use "other
people's software"?
An approach to these questions can be made by
contemplating the implications of the statement that
"many talented individuals have made great efforts" to
develop astronomical software. It is not enough simply
to talk about cooperation in a theoretical way, and it
is not possible to force cooperation. Rather, we need
to investigate practically how individuals (and
software) can begin to act in concert without
sacrificing their independence or compromising the
needs of their projects. This paper will examine these
issues through specific examples and will offer a
practical starting point for software cooperation,
centered on the concept of "minimal software buy-in".
The High Energy Astrophysics Science Archive Research
Center is the premier archive for NASA's high-energy
astronomy data. This demonstration will show a few of
the capabilities that are provided to astronomers and
the public at the HEASARC. These include:
- A complete, portable environment for analyzing high-
energy data using FTOOLS and XANADU.
Description of the demo:
We intend to access the resources of the HEASARC over
the Web and show a few programs running locally (or at
least displaying windows locally). The demonstration
will require a computer with graphical capabilities
and Netscape V3.0 or higher or Internet Explorer V3.0
and higher. It would be substantially preferable to
have a Unix system rather than a PC or a Mac. Some
tools we would like to demonstrate require X-windows
capability.
N.P.F. McKay, D.J. McKay (NRAL, Jodrell Bank)
This paper discusses the ramifications of the
relatively new Java computing environment on the field
of astronomy. It indicates the advantages and
disadvantages of the language, concentrating on the
specific needs of various aspects of astronomical
computing. To illustrate some of the concepts, the
authors present the Virtual Radio Interferometer
(VRI), which allows the demonstration of aperture
synthesis by simulating the Australia Telescope
Compact Array and other observatories in software.
This Java applet may be used as an educational tool
for teaching interferometry as well as a utility for
observers.
A. Micol (ST-ECF), P.D. Bristow (Bristol), B. Pirenne
(ST-ECF)
The implementation of On-The-Fly Re-Calibration at the
ST-ECF and CADC goes some way towards alleviating the
problem of obtaining good and timely calibration of
HST exposures. However, the data access paradigm is
still to consider each exposure individually, re-
calibrate them and offer the results to users, who
subsequently process the data further.
We describe here techniques to automatically group
together HST WFPC2, STIS and NICMOS exposures for
cosmic ray removal, co-addition and combination into
"super high resolution'" images. We show that the
execution of these tasks has been made essentially
automatic.
The ST-ECF archive now offers the possibility to
select "associations'" of datasets and the
automatically combined final products. A further spin
off of this project is that more reliable pointing
information for all exposures is provided.
Invited talk:
F. Murtagh (Univ. Ulster & Obs. Astron. Strasbg.) and
J.L. Starck (CEA)
We discuss noise in the context of astronomical image
processing, including common noise models and variance
stabilization. We then look at why multiresolution
analysis has been so successful in allowing noise to
be filtered. Multiresolution transforms such as the
wavelet transform and the pyramidal median transform
are briefly described. An innovatory data structure
in the context of such transforms, termed the
multiresolution support, is defined. Two important
application fields are investigated: firstly, image
compression; and, secondly, high-quality automated
noise determination. In the context of the latter, we
show how the same approach can be used for filtering
out anomalously high-valued artifacts (cosmic ray
glitches).
Michael L. Norman
(Laboratory for Computational Astrophysics
Department of Astronomy and
National Center for Supercomputing Applications
University of Illinois at Urbana-Champaign)
Hydrodynamic simulations of diverse astrophysical systems--
from stars to the large scale structure of the IGM--is in a period
of explosive growth as a means to rationalize observational
data as well as to understand the underlying physics. Pacing this
growth is the availability of sophisticated simulation software
as well as computer power. I describe our efforts at the Laboratory for
Computational Astrophysics to create a suite of community simulation
codes for astrophysical and cosmological simulation,
and disseminate them to the international research community. In
particular, I review the status of the ZEUS codes which are in widespread
use for astrophysical fluid dynamics simulations. I also
describe KRONOS, a new code for hydrodynamic cosmological simulations,
and 4D2, a 3D data visualization tool. These codes are illustrated
with applications to supernova remnant modeling and cosmological
structure formation at high redshift. More information about the LCA
can be found at the following website:
http://lca.ncsa.uiuc.edu/.
F. Ochsenbein (CDS, Observatoire astronomique de
Strasbourg)
The VizieR system, initially developed in a
colloboration between the ESIS project (European Space
Information System of the European Space Agency) and
CDS (Centre de Donnes astronomiques de Strasbourg),
is a tool which allows to access individual records
within a very large collection of astronomical
catalogues: the query can be a set of ontraints
applied to any column of any of the ~ 4000 tables from
about 1500 astronomical catalogues. For tables related
to astronomical objects, the query can also involve
the proximity to a specified target object.
The VizieR system essentially consists in the
conversion of the data files and their associated
description into tables of a relational DBMS. The
ingestion of such a large number of data files is
mainly the result of a large effort of rationalisation
and standardisation in the documentation of the
astronomical catalogues conducted at CDS and the
associated data centers for several years: the
inclusion of new catalogues and data-sets is now
achieved by a pipe-line processing of the standardized
catalog documentation.
An essential part of the VizieR system consists in a
set of dedicated tables contains the description of
all tabular parameters: the META database or the
Reference Directory. These tables can themselves be
referenced in queries, allowing e.g. to find out
catalogues providing data related to polarisation.
This set of META tables, which will be briefly
presented, was recently improved, leading to enhanced
performances.
The very large catalogues (e.g. the USNO-A1.0
catalogue of 488 million stars) can also be queried
from VizieR through dedicated interfaces; the access
to such large catalogues is however restricted to
small fractions of the sky for obvious performance
reasons. A generalized access from celestial positions
to a large number of catalogues will also be
presented.
The service can be accessed from URL:
http://vizier.u-strasbg.fr/VizieR.
P.F. Ortiz (Univ. Chile)
The Department of Astronomy of the University of Chile
hosts a number of astronomical databases created with
datOZ (Ortiz, 1997). This is not an ftp site, but one
in which databases are accessed interactively and in
real time by the use of an HTML interface using HTTP
as the communications protocol. Data can be retrieved
by the users in a highly flexible way, from lists of
user selected quantities, to customized plots,
including any additional multimedia information
accessible for the database elements. The latest
additions to the system point in two directions: a)
allow not only the access to the values of the defined
variables, but the construction of quantities based on
the database variables, which in turn can be used for
plotting, definition of constraints, neighbour search,
or data retrieval modes, and b) allow the retrieval
and further correlation of information stored in
different datOZ's databases, which need not to be in
the same machine.
The benefits of accessing catalogs over the WWW are
described for both research and educational purposes.
It's not the same to get an ASCII table with many
columns of data on your computer than accessing the
same data with a flexible interface which allows
immediate visualization of the data. One of the main
features of this database system is its capacity to
plot quantities upon request for defined subsets of
the data stored in the database. Visualization and
information organization are key aspects of exploiting
the content of a database.
At our Departemet, we have set databases to be
consulted (like catalogs) and databases for especific
projects, which are protected from the rest of the
world and serve the purpose of keeping the data in a
handy way and also support all the stages of the
research projects. In this paper I intend to describe
the capabilities of public databases and the benefits
a researcher or student can get from such a tool.
S. Ott (ESA) and R. Gastaud (CEA)*
The ISOCAM Interactive Analysis System (CIA) was
developed to calibrate ISOCAM, the infrared camera on
board the Infrared Space Observatory (ISO) and to
perform its astronomical dataprocessing.
Currently data processing consists of multiple steps:
o data preparation
We will review the algorithms currently implemented in
CIA, present some examples and will outline forseen
changes to accommodate future improvements for these
algorithms and the user interface.
*on behalf of the CIA development team at CEA/Saclay,
ESA/ISO/Villafranca, IAS/Orsay and IPAC/Pasadena
N. Peccia, F. Jansen, H. Nye, M. Merri, J. Riedinger
(ESA)
The XMM satellite is a powerful new X-ray observatory,
providing astronomers with the tools necessary to make
advances in high-energy astrophysics into the next
century. Launch is scheduled for 1 August 1999 by an
Ariane 5 launch vehicle with insertion into a highly
eccentric, high inclination orbit, having a perigee
height of 240 km, apogee height of 114,000 km and an
orbital period of 47.8hrs. The mission will be of long
duration, with a design lifetime of 27 months and
consumables to extend the mission for up to ten years.
The payloads will be used to generate a high
throughput of data, which will eventually be
accessible to the world wide astronomical community.
The XMM Science Control System (XSCS) is based at the
Vilspa groundstation in Villafranca, Spain. It is
responsible for allowing the astronomical community to
submit proposal for observations via the Proposal
Handling Subsystem (PHS). These proposals are then
manually evaluated for scientific worth, those
accepted being passed to the Sequence Generation
Subsystem (SGS). This produces a schedule, the
preferred observation sequence (POS), on a revolution
by revolution basis, based on the submitted proposals
and orbital constraint data supplied by Flight
Dynamics at ESOC, Darmstadt Germany. Once a POS is
produced it is sent to ESOC for further processing and
eventually uplinked to the spacecraft from the XMM
Mission Control System (XMCS) at ESOC. All telemetry
received from the spacecraft by the XMCS is routed
back to the XSCS via TCP/IP over dedicated leased
lines. This data is received by the Payload Monitoring
Subsystem (PMS) where standard SCOS-1 functions
provide monitoring of instrument housekeeping data.
Additional, mission specific functions, provide
monitoring of the science data. In particular the
Quick Look Analysis (QLA) subsystem enables the
monitoring of the science data images as they are
received. This also enables ?changes requests? to be
generated which are sent to the XMCS for uplink to the
spacecraft. These are in effect commands enabling the
settings of an instrument to be tuned during an
observation. All science telemetry received by the PMS
is further processed by the Observation Data Subsystem
(ODS) which turns the data into FITS format files.
These FITS files are then send to the Survey Science
Centre (SSC) in Leicester, U.K., for detailed
scientific analysis (Pipeline Processing). The
products of this analysis are then returned to the
XSCS where they are storied in the Archive Management
System (AMS) and made available to the scientific
community. External users can browse the archive, via
a web based interface, and request data from it. Due
to the size of the data sets the main medium of data
distribution is CD-ROM. Additionally the SOC is
responsible to maintain the Instruments On-Board
Software during the Mission. The Instrument Software
System ( ISS ) replicates all the Instruments Software
Development Environments (SDEs) and validates the on-
board software changes ( only instrument controllers)
by using a simulator ( SOC simulator ). The XSCS is
implemented on a variety of platforms, Alpha/OpenVMS
for the PMS and ODS, Sun/Solaris for the PHS, SGS, AMS
and QLA. All web interfaces are based on a Windows NT
platform. In order to handle the data produced during
the lifetime of the XMM mission (currently estimated
at 2 - 4 Terabytes) a Hierarchical Storage Mechanism
(HSM) is used in the AMS to provide sufficient data
storage capacity.
J.A. Pollizzi, III, K. Lezon (STScI)
The Hubble Space Telescope (HST) generates on the
order of 7,000 telemetry values, many of which are
sampled at 1Hz, and with several hundred parameters
being sampled at 40Hz. Such data volumes would
quickly tax even the largest of processing facilities.
Yet the ability to access the telemetry data in a
variety of ways, and in particular, using ad hoc (i.e.
no a priori fixed) queries, is essential to assuring
the long term viability and usefulness of this
instrument. As part of the recent NASA initiative to
re-engineer HST's ground control systems, a concept
arose to apply newly available data warehousing
technologies to this problem. The Space Telescope
Science Institute was engaged to develop a pilot to
investigate the technology and to create a proof-of-
concept testbed that could be demonstrated and
evaluated for operational use. This paper describes
this effort and its results.
First a background is given to contrast data
warehousing technology from the more familiar
relational database technology. Then how HST telemetry
challenges any attempt at a queriable system is
described. The paper follows with the various choices
and compromises we made in how to best use a
particular warehouse product in meeting this goal. The
paper then summarizes with lessons learned and some
actual benchmark results taken from the effort.
Invited talk:
S. Schaller (Steward Observatory)
Quality system management of computer workstations can
be achieved with relatively small manpower
requirements, if the right cost-effective
administrative design decisions are made.
Recent dramatic changes in the price/performance ratio
of computer hardware have modified the model used to
distribute computer resources and especially the usage
of the network.
Invited talk:
J. Schwarz (ESO)
Now that the computer has passed from a useful to an
indispensable tool in every astrophysics research or
teaching institution, its administration has become
serious business. Today's user expects continuous,
uninterrupted service from the computer and its
environment of networks and peripherals. System
crashes and scheduled downtime during working hours,
which used to be regarded as facts of life, are now
considered unacceptable by most users. In the face of
expectations such as these, infrastructure planning,
dependable maintenance service, and resource
optimization are required of anyone who is responsible
for an Information Technology (IT) center.
The IT center can no longer afford to let equipment
wear out before replacing it; a planned roll-over of
all IT hardware is necessary. Likewise, only an
implausibly manpower-rich computing facility can
afford to maintain a widely varied mix of computer
makes and models; an inexpensive clone of a major
brand may prove to be a major maintenance headache
later. In the very bastion of academic freedom, hard
choices may have to be made about just how much
freedom the user is to be allowed in choosing a
desktop computer system. "You can buy it but we won't
support it" is easy to say, but hard to fall back on
when the user's odd-brand machine crashes before a
major observing proposal deadline. And is Information
Technology the 'core business' of an observatory? Why
not outsource the whole messy affair? These and other
related issues will be discussed (though not resolved)
at the conference.
S. Scott, R. Finch (Caltech/OVRO)
A new user interface for the OVRO Millimeter Array is
in the early phase of implementation. The basic
requirements are to provide monitoring and control of
the array with a web based interface from anywhere on
the Internet. Low bandwidth connections that are
typically attained with analog modems must provide a
satisfying interface.
Web browser based clients have been developed to
display monitoring information from the array that is
updated in realtime. These monitor clients are written
in Java and are tailored to present different sets of
information about the array. The data are usually
rendered as numerical text values in data cells, with
the color of the cells representing the state of the
component. Many of the data cells are arranged in
tabular form to provide a dense display and to
emphasize the relationship of the data. The data cells
in the table also function as the selection menu to
initiate live realtime plots. This flexible plotting
is a key feature of this new interface. Data caching
and compression are two techniques used to enhance the
utility of the monitor clients.
The monitoring clients are fed data over TCP/IP
circuits from Unix server programs. These C++ server
programs get their data from a large shared memory.
The shared memory is updated twice a second by demon
programs that receive datagrams from microprocessors
embedded in the array hardware.
The control aspect of the interface is in the design
stages as the Java security model evolves to provide
the flexibility needed for remote access to control
functions.
We briefly describe the ISO Spectral Analysis Package
ISAP. This package has been and is being developed to
process and analyse the data from the two
spectrometers on board ISO, the Infrared Space
Observatory of the European Space Agency (ESA). ISAP
is written in pure IDL. Its command line mode as well
as the widget based graphical user interface (GUI) are
designed to provide ISO observers with a convenient
and powerful tool to cope with data of a very complex
character and structure. ISAP is available via
anonymous ftp and is already in use by a world wide
community.
Suggested presentation: Demo
I. Taylor (Univ. Wales)
For the demo, I will be giving a 'hands on'
demonstration of the Grid OCL system. People in the
conference can come up and try Grid OCL out for
themselves or can be given a tour of the Grid OCL
system including demonstrations of how to : create and
connect units; group units to make custom
configurations; import, export and display various
different types of data; use the 2D Graphical
displayer to zoom in/out etc; and also write custom
units which can then, in turn, be used in the same way
as other units within the Grid OCL system.
The Image Reduction and Analysis Facility (IRAF) is an
image processing and astronomical data analysis system
developed by the IRAF group at the National Optical
Astronomy Observatories (USA). The ADASS IRAF demo
will feature the newly released IRAF Version 2.11, the
latest X11IRAF visualization tools, portions of the
Mosaic Data Handling System used for CCD data
acquisition, and the distributed object and message
bus data system framework being developed by NOAO.
The IRAF group will be available to answer questions
about the various aspects of the IRAF installations,
reductions and programming tools.
Specific description of the demo:
We plan to demo the IRAF system. We will need a
workstation or the equivalent: 17-20" color monitor,
600Mb of diskspace, a minimun of 32Mb of memory, SunOS
or Solaris operating system running X Windows, DAT,
Exabyte, or CD drive for downloading the software
initially. We prefer a Sun workstation if at all
possible.
D. Tody(NOAO/IRAF)
In this decade we have seen software become
increasingly large and complex. Although programs may
be well structured internally, using hierarchically
structured class libraries to modularize the code, our
programs have grown so large that they are monolithic
and inflexible with a high degree of interdependence
of the internal modules. The technology needed to
address this problem, being developed now by academia
and commercial consortiums, is known as distributed
objects. Distributed objects allow major software
modules to be encapsulated as objects and instantiated
as separate processes, threads, or classes
(procedures). Tying it all together is the message
bus, which provides flexible services and methods for
distributed objects to] communicate with one another.
Applications are built by linking precompiled
components and services together at runtime on the
message bus. This paper presents the message bus and
distributed object framework being developed by NOAO
and outside collaborators as part of the Open IRAF
initiative. This project is funded in part by the
NASA ADP and AISR programs.
The design of a data reduction system for the NOAO
Mosaic Camera was presented at the ADASS VI
conference. This paper reports on the first
implementation of this system as an IRAF package.
Details and examples of the tools are given.
Particular attention is given to the central role
played by the coordinate system in producing high
quality final images from a mosaic of CCDs.
The VLT Science Archive System
Astronomy On-Line - the world's biggest astronomy event on
the World-Wide-Web
TAKO: Astro-E's Mission Independent Scheduling Suite
Suggested presentation: Demo
European Southern Observatory - MIDAS + SKYCAT
Parkes Multibeam realtime object-oriented data
reduction using AIPS++
Object-Relational DBMSs for Large Astronomical
Catalogues Management
Parallel tree N-body code: data distribution and DLB
on CRAY T3D for large simulations
Teaching Astronomy via the Internet
Suggested presentation: Demo
Demonstration of Starlink Software
Nightly Scheduling of ESO's Very Large Telescope
CyberHype or Educational Technology - What is being
learned from all those BITS?
How to exploit an astronomical gold mine: Automatic
classification of Hamburg/ESO Survey spectra
Building Software Systems from Heterogeneous
Components
Suggested presentation: Demo
Demonstration of AIPS++
VRML and Collaborative Environments: New Tools for
Networked Visualization
Fitting and Modeling of the AXAF Data with the ASC
Fitting Application
New Capabilities of the ADS Abstract and Article
Service
Object-Oriented Experiences with GBT Monitor and
Control
News on the ISOPHOT Interactive Analysis (PIA)
Distributed Searching of Astronomical Databases with
Pizazz
Achieving Stable Observing Schedules in an Unstable
Worls
New applications of Artificial Neural Networks in
stellar spectroscopy
New applications of Artificial Neural Networks in
stellar spectroscopy
ASCA: An International Mission
A Trans-Continental Local Area Network
SAOimage: The Next Generation (SAOtng)
Other People's Software
E. Mandel (SAO)
Suggested presentation: Demo
The HEASARC on the Web
T. McGlynn, W. Pence, N. White, S. Calvo, M.
Duesterhaus, P. Newman, S. Zobair, C. Rosen, E. Sabol,
L. Brown, B. O'Neel, S. Drake, L. Whitlock (NASA/GSFC)
- Astronomical information from more than a dozen
missions on the web using W3Browse.
- Immediate and easy searching of many HEASARC and
remote Web sites for astronomical objects using the
Astrobrowse system discussed at this meeting.
- The multi-wavelength virtual telescope: SkyView.
- Sophisticated educational resources for children and
adults of all ages.
Using Java for Astronomy: The Virtual Radio
Interferometer Example
Constructing and Reducing Sets of HST Observations
Using Accurate Spacecraft Pointing Information
Noise Detection and Filtering using Multiresolution
Transform Methods
Invited talk
Early Universe Simulation
Software for Astrophysical and Cosmological Hydrodynamics Simulations
The VizieR system to access astronomical data
Accessing astronomical data over the WWW using datOZ
Data Analysis with ISOCAM Interactive Analysis -
preparing for the future
o cross-talk correction
o dark current substraction
o flat-fielding
o deglitching
o transient correction
o mosaic generation
o generation of spectra
o interfacing with non-ISO data products
The XMM Science Operations Centre Control System
A Queriable Repository for HST Telemetry Data, A Case
Study in using Data Warehousing for Science and
Engineering
The VLT Data Flow System : A Progress Report
Peter J. Quinn (ESO)
In order to realize the maximum scientific return from the VLT, ESO has
undertaken to develop an end-to-end data flow system from proposal entry
to science archive. The VLT Data Flow System (DFS) is being designed and
implemented by the ESO Data Management Division in collaboration with VLT
and Instrumentation Divisions. Tests of the DFS started in October 1996 on
ESO's New Technology Telescope. Since then, prototypes of the Phase 2 Proposal
Entry System, VLT Control System Interface, Data Pipelines, Online Data
Archive, Data Quality Control and Science Archive System have been tested.
Several major DFS components have been run under operational conditions
since July 1997. This presentation will give a summary of the current state
of the VLT DFS, the experience gained from prototyping on the NTT and the
planning for VLT operations beginning in early 1999.
Cost-effective System Management
Managing Information Technology Infrastructure
The New User Interface for the OVRO Millimeter Array
The ISO Spectral Analysis Package ISAP
E. Sturm, O.H. Bauer, D. Lutz, E. Wieprecht (MPE), G.
Helou, I. Khan, S. Lord, B. Narron, S. Unger (IPAC),
M. Buckley (RAL), F. Vivares (CESR), L. Verstraete
(IAS), P.W. Morris (ISO SOC)
Demonstration of the Grid OCL System
IRAF Suggested presentation: Demo
D. Tody and the IRAF Group (NOAO/IRAF)
Open IRAF Message Bus and Distributed Object
Technology
The IRAF Mosaic Data Reduction Package
F. Valdes (NOAO/IRAF Group)