Online Access to the NSSDC/SPDF Satellite Situation Center (SSC) Software System

Volume 11, Number 1, March 1995

By Bob McGuire

A unique capability to cast Earth-orbiting spacecraft orbits against empirical models of the boundaries of various regions of geospace, and a variety of internal/external magnetic field models for field line tracing in the magnetosphere, is available online in the Satellite Situation Center system (jointly operated by the NASA/GSFC National Space Science Data Center and its sister organization, the Space Physics Data Facility).

The software supports:

Tabular output of spacecraft location (Cartesian or polar) as a function of time and in a variety of geophysical/geomagnetic coordinate systems. Filters may be defined to list only times/locations that are minima/maxima or within a user-specified range of values in any of the supported output parameters).
Graphical output of multiple spacecraft orbits (for users with X-windows release 5 or greater and PEX extensions installed, along with good network connections to GSFC).
Lists of time periods when one or more selected spacecraft are in the same magnetospheric region or a specified combination and
Lists of time periods when spacecraft are in magnetic conjunction with each other or with specified ground stations/ground locations.

The user-accessible system runs from the same database (some 33 spacecraft, with current and planned launches populated with predictive, as well as definitive data as available) that is used by the SSC operations staff and by the ISTP Science Planning and Operations Facility. The database and SSC system are one of several international capabilities that will be used in support of upcoming solar-terrestrial observational campaigns to be conducted under the auspices of the InterAgency Consultative Group (IACG). The database is frequently updated to include the latest orbital information on space physics missions of current interest.

Access to the system is possible via World Wide Web (at the URL http://nssdca.gsfc.nasa.gov/spds/ssc.html or via the Space Physics Data System home page at http://nssdca.gsfc.nasa.gov/spds/spds.html) or by direct "telnet" connection to the account "captive" at "sscop1.gsfc.nasa.gov". Note access via WWW is ultimately still via telnet/rlogin connection to the underlying system and user interface at the present time. Extensive online help is available; a postscript version of the current User's Guide (version 2.1) is available via anonymous ftp to sscop1.gsfc.nasa.gov in the subdirectory SSC/documentation/. A new release of the software with updated region and field definitions and extended functionality is expected in about two months.

The operational SSC facility also supports:

Use of several staff-run magnetospheric/heliospheric codes to support special investigations.
Access to precomputed magnetospheric/heliospheric files of trajectory data and other information of general interest accessible via anonymous ftp to the ACTIVE subdirectory on the node nssdca.gsfc.nasa.gov.

We encourage comments to the system functionality and usability from all interested users. Those may be sent as a direct option within the system or as electronic mail to the author (at the Internet address mcguire@nssdca.gsfc.nasa.gov) as most convenient.

NASA home page

GSFC home page

GSFC organizational page

Author:Miranda Beall
Curators: Erin Gardner and Miranda Beall
Responsible Official: Dr. Joseph H. King, Code 633
Last Revised: 04 Dec 1996 [EDG]