Review of VO science Cases in relation to Registries
Mark G.Allen
allen at newb6.u-strasbg.fr
Fri Apr 11 09:35:48 PDT 2003
Hi Everyone,
I've made a quick review of the current VO science cases
with respect to registries. The idea is to motivate
discussion on the Key Science Cases to be used as drivers
for development of registries. Also I thought it might be useful
just to have a list of science cases on the same page.
I haven't gone so far as to draw general conclusions from them,
but this will be part of the next steps.
I've listed 5 of these cases as particularly relevant to
registries, onto the http://www.ivoa.net/twiki/bin/view/IVOA/IVOARegWp02
page, which we can call the v0.1 of the "Key Science Cases
for Registries" document which is scheduled for today, April 11.
More detailed analysis of these cases is needed. NVO have
done some of this with their draft Registry Use Cases and
draft Registry Requirements.
Other immediate questions are:
Are there elements of other science cases not picked up in
those drafts?
Do we need other Science Cases as drivers for Registry
development?
-Mark.
Review of VO Science Cases in Relation to VO Registries.
--------------------------------------------------------
v1.0 M.Allen. April 11, 2003.
A goal of RWP02 is to identify Key Science Cases to be used
as drivers for defining registry requirements. These should be
illustrative of the range of requests that may be sent to a
registry.
These notes are an attempt to review the current science cases
from the various VO initiatives, in relation to VO registries.
Some of the individual groups have already made some assessment
of their science cases with respect to registries, and these notes
draw directly from those assessments. I've paraphrased the various
cases, and made short notes with respect to registries. This is
really a first pass, and may sometimes border on statements of the obvious,
so please feel free to comment or change anything here.
List of Current VO Science Cases:
---------------------------------
* AstroGrid *
AstroGrid has a fairly well developed set of science cases including
sequence diagrams described on the follow pages:
http://wiki.astrogrid.org/bin/view/Astrogrid/ScienceProblems
http://wiki.astrogrid.org/bin/view/Astrogrid/SequenceDiagrams
1. Brown Dwarf Selection
2. Deep Field Surveys
3. Galaxy Clustering
4. Hi-Z Quasars
5. Low Surface Brightness Galaxy Discovery
6. Magnetic Storm Onset
7. Solar Coronal Waves
8. Solar Stellar Flare Comparison
9. STP Solar Event Coincidence
10. Supernova Galaxy Environment
* NVO *
NVO developed a number of science drivers for their demos, and also have
a number of Registry Science/Use Cases posted to the Registry mail list.
(N.Gaffney)
1. Find Super Novae Pre-Burst Observations
2. Select Dwarf Galaxies by Colour for Observational Follow-up
3. Construct Highest Signal-to-Noise V-band image of sky region
(T.McGlynn)
1. Find all object catalogs derived from a mission
2. Find queriable image-cutout services with sky coverage and
galactic coordinate criteria.
Gamma Ray Burst Demo +
Other demo cases...
* AstroVirtel *
AstroVirtel have a draft document on the registry relevant aspects
of one of their current science cases:
Luminosity functions of Star Clusters in Nearby Galaxies (De Grijs).
The document is on the wiki at
http://www.ivoa.net/internal/IVOA/RegistryUseCases/astrovirtel_use_case.pdf
(A.Micol)
* AVO demo science case *
This science case was related to finding red objects in the GOODS
data. The demo used the GLU as implemented with a customized Aladin
and a VOTABLE metadata tree that works a bit like a registry, but
perhaps this is more related to data model issues. (A general
meta-data tree function for Aladin is to be announced on the DM
mailing list very soon)
Notes on the Current Science Cases with respect to Registries:
--------------------------------------------------------------
* AstroGrid *
This is taken directly from their sequence diagrams where "resource
catalog" is taken to mean Registry. (is that correct?)
1. Brown Dwarf Selection
* Search the resource catalog for catalogs containing Galactic clusters
- Registry needs to be able to identify resources which provide
catalogs, and be able to find those relevant to "Galactic Clusters"
* Query registry for catalogs with coverage of I, K, or R wavelengths
over each cluster location
- Registry needs to be able to select catalogs based on wavelength
and spatial coverage
- In general the registry is expected to return lists of catalogs
2. Deep Field Surveys
* Search the resource catalog for optical and radio deep field
surveys with wavelength, instrument, sensitivity, dynamic range,
epoch, and resolution metadata. A list of surveys is returned and
one or more are selected
- Registry needs to be able to identify deep field surveys
- Registry needs observation specific info: instrument, sensitivity,
dynamic range, resolution
- Registry needs epoch or temporal coverage information
- Registry is assumed to return lists of surveys/catalogs with the
possibility of making selections from these.
3. Galaxy Clustering
* Search the registry for galaxy catalogs.
- Registry needs to be able to identify galaxy catalogs
* After selecting sources, search the registry for a spectrographic
catalog to query by coordinates.
- Registry needs to be able to identify resources with spectral
catalogs, and say whether those catalogs can be queried by coordinates
4. Hi-Z Quasars
* This case is focused on using large surveys
- Registry required to locate those survey resources, and provide
information on how they can be queried.
5. Low Surface Brightness Galaxy Discovery
* Locate large scale structure with low contrast to background
- Registry needed to locate surveys, how to query them...
6. Magnetic Storm Onset
* Locate an on-line source of data for that spacecraft and request
data for a time window around each magnetic storm.
- Registry required to locate data source, and whether it can query
with temporal parameters.
7. Solar Coronal Waves
8. Solar Stellar Flare Comparison
9. STP Solar Event Coincidence
10. Supernova Galaxy Environment
* Search literature and published sources for possible spectroscopic
redshifts of galaxies in fields.
- Registry provides location of publication resources, and how
to query them for keywords like "galaxy" and "redshift"
* Search archives for spectroscopic data of objects in field
- Registry needs to identify spectroscopic databases
- Registry needs spatial coverage information for databases
* NVO *
1. Find Super Novae Pre-Burst Observation
* get all IR, Optical, and UV data (derived photometry or images or
spectra) from any data source that may have been observing it
during a specified time period
- Registry required to locate all data at a given point, i.e. spatial
and temporal coverage
* get all observations that have a chance of detecting/resolving it
- Registry would need sensitivity and resolution information about
observational data.
2. Select Dwarf Galaxies by Colour for Observational Follow-up
* get colors U-K and R-H (either colors, magnitudes, or data from
which magnitudes can be extracted in that order) for dwarf galaxies
with known V magnitudes and redshift or absolute V magnitudes
- Registry needs to identify catalogs of dwarf galaxies, and
whether they contain colour or magnitude measurements
* I would like to know which services that provide the colors I
need are based on other data in the VO, so I don't redo the
color measurement when I don't have to
- Requires knowledge of provenance of data in catalogs
3. Construct Highest Signal-to-Noise V-band image of sky region
* need all independent observations (e.g. not based
on the same raw data) at V of this area of the sky that have a
resolution and pixel size on the sky of at least 1 and 0.5 arcseconds
respectively
- Registry needs to identify independent obs in a region of sky
- Requires resolution and pixel size information of registered
archives.
4. Gamma Ray burst +
Not detailed here, but RayPlante says he'll:
"Summarize how a registry will be incorporated into the NVO Gamma Ray
Burster demo (making it a general-purpose "show me the sky" tool)."
* AstroVirtel *
Alberto's document provides quite a lot of detail from their
practical experience of running VO-like science cases. Here
I've tried to make a summary for general consumption.
Types of Service identified within a Registry
--------------------------------------------
The AstroVirtel use case scenario identifies requirements
for registries, in terms of the types of services a
registry should be able to identify.
The types specific to the given example scenario are
- Catalog Browser Services - e.g. a catalog search engine like VizieR
- Services relating to a particular class of astronomical
objects, e.g. Galaxies
- Services providing particular types of data, e.g. Astronomical
Object Catalogs, Image Data
- Services that directly provide particular output parameters
e.g galaxy name ID, galaxy position, galaxy type
- Services that can be constrained by a given parameter, such
as distance.
Further, registered services should give some idea of the
- number of records available
- wavelength or passband coverage
- minimum resolution
- calibration status of data
More information about the registry
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