Converging Computing Methodologies in Astronomy: Scientific Background
The increasing integration in an astronomical setting of various
methodologies in pattern recognition, information retrieval and data
analysis is a characteristic of modern computational astronomy. Large
astronomical databases and archives from space-borne missions, ground-based
observatories, and large wide-field surveys, provide the technological
Against this backdrop, boundaries between theoretical domains have been
lowered. A number of leading cases, and lessons to be drawn, will be
The astronomical application domain offers a unique test-bed for
establishing strengths and limitations of these methodologies (and it
offers in addition an exportable model for other domains also). Astronomy
is an on-line, nearly all-digital science, with high visibility, and a
specifiable research community: these characteristics provide a fertile
basis for dissemination of research results.
- Automated galaxy counts from digitized images (e.g. through use of the
COSMOS machine in Edinburgh, or with the MAMA machine in Paris) from
digitized images lead to a fundamentally new vision of the Universe.
The problem here goes considerably beyond image analysis: it raises
various other problems which are solvable with pattern recognition and
statistical methods. The number of objects treated, in this instance
and in applications to be described in the following, may be many
tens of millions.
- The use of large image databases and archives necessitates new image
retrieval and textual retrieval methods. The latter includes both
image-associated descriptive text, and also retrieval from bibliographic
databases. Modern astronomical retrieval systems allow seamless
access to information in its varied forms (graphical, image, textual,
bibliographic, etc.), alongside semantic support (e.g. name resolvers).
- Multiresolution image analysis, mathematical morphology and fuzzy object
characterization are increasingly integrated. Thus wavelet
transform analysis is used for image restoration and filtering, with
semantics built in through morphological operations on the transform.
Fuzzy object characterization is a valuable interpretational facet.
- Cross-identification of large catalogs (IRAS, ROSAT, etc.) are necessary,
both for scientific analysis, and as an indispensable basis for
missions (e.g. the Hipparcos Input Catalog, INCA). Cross-identification
of data is one aspect; a further turn of the same spiral leads to the
issue of the cross-correlation of information.
Current and on-going organisational and meeting-related initiatives
include the following. These provide a
backdrop to the project which can be beneficially used to communicate the
project's results to a wider audience. From the project point of view, they
are driven by subsets of the overall domain of interest.
- Conferences such as the Data Analysis in Astronomy series, in
(approximately every 3 years); the Data Analysis in Astronomy series
hosted at the European Southern Observatory (now discontinued); the North
American Astronomical Data Analysis Software and Systems (ADASS) annual
series; more irregular conferences on topics such as statistical methods
in astronomy, or astronomy from large databases with emphasis on data
- Organisations such as the International Astronomical Union (IAU)
the Working Group for Modern Astronomical Methodology (irregular
newsletter; now inactive); Technical Committee 13 of the International
Association for Pattern Recognition; the Italian Chapter of the
International Association for Pattern Recognition; the American
Astronomical Society Working Group on Astronomical Software (email
exploder, contributions to Bulletin of the American Astronomical
Society, and AAS meetings). Strasbourg Observatory publishes the
regular CDS Bulletin. The IAU Working
Group on Wide-Field Data publishes a regular extensive newsletter.
- For information distribution in astronomy, the World-Wide Web has become
the de facto standard. The AstroWeb consortium (7 individuals at some
of the major institutes in Europe, the US and Australia) has consolidated
a common list of more than 1000 astronomical sites worldwide.
Last update: 2.12.94.
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