JPL Provides Variety of Data, Software Via NSFNET

By Jim Knighton
Jet Propulsion Laboratories

Accessing the Internet via a personal computer can yield a wide variety of data - both Earth and extraterrestrial - as well as the tools to use these data. Government agencies, such as NASA, maintain online data catalogs with archived measurements related to meteorology, climatology, geology, and oceanography taken from ground-based and satellite instruments.

In addition, NASA maintains an online catalog of planetary data which have been collected from various observatories around the world and from unmanned probes such as the Ranger mission to the moon through the Voyager encounter with Neptune.

After August of this year, Magellan data showing the surface of Venus will begin streaming in to be cataloged and redistributed.

Data systems

A fairly complete list of these services can be found in the NASA report, "Earth and Environmental Science in the 1980's: Part 1, Environmental Data Systems, Supercomputer Facilities, and Networks". Immediate access to the National Space Science Data Center catalog, (maintained at Goddard Space Flight Center in Maryland) can be achieved by connecting to: (

A captive account with the username NSSDC will put you into a catalog system containing references to data sets from both NASA and NOAA, together with information for ordering these or contacting the responsible individuals who can provide further information.

Similar catalogs are maintained by the NASA Oceans Data System, NASA Pilot Land Data System, the National Climate Data System, and the NASA Planetary Data System.

Further information regarding access to these data systems can be obtained from the addresses provided at the end of the article.

Available software

Access to these data sets is made considerably more useful with the addition of one or more of the public domain software packages now available over the Internet.

The National Science Foundation, the National Institute of Health (NIH), and other government and educational organizations have funded several efforts with the purpose of providing analytical tools which can be used in a distributed, heterogeneous computing environment.

Tools run on variety of machines

These tools, which include image processing, data formatting, plotting, communications, and interactive measurement features, have been written to run on machines from Cray 2's to Macintoshes.

Several tools, such as the National Center for Supercomputer Application's (NCSA) Telnet and Imagetool programs work on several platforms, while others, such as the IMDISP (image display) package available from the NASA Planetary Data System, are designed specifically for the IBM-PC.

Power to the desktop

Taken together with the data, these tools make a desktop computer such as the Macintosh II, a full-feature image processing workstation. At the Jet Propulsion Laboratory, we have combined features from several of the public domain packages, including NCSA Imagetool and ImageIP and NIH Image, with those from commercial analysis and art packages such as Spyglass Transform and View, PixelPaint, and Data Desk, to form the prototype of an end-to-end data integration system allowing the combination of multisensor data into higher level products.

We have interconnected all levels of our local computing capability from personal computers at the scientists' desks, through midlevel machines such as Sun and Decstation minicomputers, to our Cray and Hypercube facilities.

Processing is controlled from the small machines, but those computations requiring real horsepower are performed on remote, more capable equipment with the results shipped back, in compressed format to the desktop.

Software from public domain

All of the software needed for the control, x-y reference measuring, index image display, and final product output are derived from the public domain packages. This approach has allowed us to take immediate advantage of our distributed processing capabilities using such well developed platforms as the NASA, VICAR image processing libraries on their native machines without the necessity of porting the software to local, disconnected computers.

Further information

The software discussed here can be obtained by anonymous ftp from: ( and includes source code for:

Imagetool-Image processing and plotting software
PalEdit-Palette editor for use with Imagetool
ImageIP-A more sophisticated image processing package, including interactive 3D
Contour-A contour plotting package
Telnet-TCP/IP, Internet communications
Layout-Presentation graphics package
HDF-Hierarchical data formatting tools for sharing data between different architectures

Software for NIH Image binaries and source can be obtained from while Software and data from the NASA Planetary Data System can be obtained from:

Michael Martin
JPL, MS 301-280
4800 Oak Grove Drive
Pasadena, CA 91109

Information regarding these and other public domain software and their integration with commercial packages can be obtained from the author of this article by surface mail at:

Jim Knighton
JPL, MS 169-237
4800 Oak Grove Drive
Pasadena, CA 91109
or via the Internet using:


Taken from The Link Letter, Vol. 3 No. 3, July/Aug 1990.