The Planetary Data System Web Catalog Interface: Another Use of the Planetary Data System Data Model

J. Steven Hughes 
Ann M. Bernath

MS 525-389
4800 Oak Grove Dr.
Pasadena, CA
91109

(818) 306-6030
shughes@jplpds.jpl.nasa.gov

The Planetary Data System (PDS) Data Model grew out of the need to
supply information about science data in an easy-to-read format.
The requirement was that scientists receiving data from the PDS
should be able to become familiar with the data using common
hardware platforms and a variety of simple tools.

The resultant Object Description Language (ODL), the Planetary
Science data dictionary, and a standardized method for describing
objects has been enthusiastically accepted by the Planetary Science
community. Using these standards, over 30,000 orders, representing
80 terrabytes of data have been filled and distributed to the
community.

In addition to labeling the science products, the PDS also expanded
the data model to collect catalog and inventory data. This includes
inventory information for data sets, collections of data sets, and
CD-ROM volumes as well as descriptive information for targets,
spacecraft, instruments, and missions. The PDS has had a online
data set catalog available since 1990 in which users can search for
and order PDS science data and browse the descriptive data.

The advent of the World Wide Web (WWW) has given the PDS the means
to simplify access to Planetary Science data. The net is available
to most of the Planetary Science community, WWW client software is
readily available for most hardware platforms, interface
development is relatively easy, and a more common look-and-feel is
presented to the users. In addition, the PDS has found that the
translation of the PDS data model from ODL ASCII labels to the WWW
HyperText Markup Language (HTML) has proven to be very easy.

The proposed paper first presents a brief history of the PDS data
model followed by a description of the software developed to
process PDS labels and produce the WWW interface.  This includes a
discussion of the ability to adapt the software to any label with
an ODL type of syntax. The particular use of this software for the
PDS project will is then presented including a list of planned
enhancements. This is followed by a discussion on lessons learned.
This paper has been submitted and selected for presentation at the
14th IEEE Symposium on Mass Storage Systems. If selected, copies of
the paper will be made available at this conference. The
presentation will be customized to emphasize the WWW catalog
interface development.