Subject: [!] Web Tools for Astronomical Catalog Viewing

From: Vincent Kargatis <kargatis at jackaldog.gsfc.nasa.gov>
Date: Thu, 02 Apr 1998 12:03:49 -0500

New Web-based Archive Tools at the ADF

Richard A. White, Cynthia Cheung (NASA GSFC)
Kirk Borne,  Ed Shaya, Jim Blackwell, Vincent Kargatis (Raytheon STX)
Jeff de La Beaujardiere (UMBC)

The Astrophysics Data Facility (ADF) at NASA Goddard Space Flight
Center has introduced a new series of World Wide Web based tools for
browsing and manipulating the Astronomical Data Center (ADC) archives
and using the results to query other data centers for information.
These developments serve both to modernize access to the ADC and to
come into compliance with Astrobrowse, the communication protocols
being established for astronomical data centers.

These Web based tools are:

1) VIEWER - a fast and simple way to view ADC catalogs and create
subset tables based on user selected data ranges.

2) CATSEYE - creates plots of table data and allows interactive query
for information on individual plotted data points.

3) IMPReSS - searches a database for observations made by NASA
missions that are within user selected regions of the sky, plots the
perimeters of these observations on a sky map, and queries the archive
sites for the data and browse data.  IMPReSS may also be used
independently with user supplied coordinates or object names (which
are resolved into coordinates through hidden queries to NED and
SIMBAD).

To reach all these web tools and for more about future developments,
see the web page located at:
  http://adf.gsfc.nasa.gov/adf/visualization/

Full descriptions:

  VIEWER

The VIEWER can be accessed in several ways at the ADC home site.  It
begins either with its own catalog selection page or through the
ReadMe page of any ADC catalogs or journal table holding selected
through the standard ADC pages.  Each catalog in the ADC is composed
of one or more tables and the user is prompted to select from amongst
these.  Then, detailed information on each column composing that
table, is presented, including the range limits (for numerical
fields).  The columns of interest can be selected and for each column
user preferred limits on the range of values can be set.  The
requested subset of the catalog is returned along with a legend that
includes information on the units and meaning of each column.

One can sort the output table by the values of a chosen column,
download the file, or rename for further use.  If the table is not
renamed, it is overwritten by subsequent tables.  User work areas are
identified by cookies that expire after 4 days.  All of the user
created tables can be plotted by another tool called CATSEYE.

  CATSEYE

CATSEYE is a tool that makes scatter plots of numerical columns from
the VIEWER output tables.  It first presents a list of all of the
tables that a user has created in the last 4 days.  The user selects
which tables should be plotted together and which columns of each
table are to be used for the x-axis and the y-axis.  Several plot
symbols are available.

Below the plot there is a table to fill in that allows one to reset
limits for the axes or to change to logarithms in either or both axes.
All plots are GIF images and may be saved locally by the user's
browser and printed.  When the mouse is used to click on a datapoint
of interest, the entry line from the appropriate table and that
table's name are displayed in a third frame.  In crowded plot regions,
more than one line from one or more tables may be displayed.  Finally,
one can click on the letter "I" (for IMPReSS) at the beginning of the
entry line to input the positional coordinates of the object to
IMPReSS.

  IMPReSS (IMage PeRimeters of Sky Surveys)

IMPReSS is a graphical interface to astronomical observing logs that
presents the user with plane of the sky outlines or silhouettes of
pointed observations obtained by space-based telescopes.  It searches
for NASA missions that have observed within the user selected region
of the sky.  It displays the aperture footprints (fields-of-view) on
the sky, overlaying multiple observations where necessary.  The search
can also be restricted by the observation date.  Once the user has
selected sets of observations of interest, IMPReSS will aid in
retrieving publicly available data by sending requests to data archive
sites for detailed information, browse images, and data files.

Although the emphasis is on obtaining targeted mission data, IMPReSS
also provides links to all-sky surveys and automates the procedure of
obtaining cutouts that cover the user's selected region.

The primary archive sites for which IMPReSS currently holds metadata
are: the National Space Sciences Data Center (NSSDC), the High Energy
Astrophysics Science Archive Research Center (HEASARC), and the Space
Telescope Science Institute (STScI).

-- 
Vincent Kargatis                Address:  Code 631
Archive Scientist, Raytheon STX           Goddard Space Flight Center
PH   301-286-6128                         Greenbelt MD 20771
FAX  301-286-1771               e-mail:   kargatis at xfiles.gsfc.nasa.gov