The EOS Data and Information System (EOSDIS) will provide a structure for data management and user services for derived products from EOS satellite instruments slated for launch over the next two decades and other NASA Earth science data. Within the EOSDIS framework, the Distributed Active Archive Centers (DAACs) are responsible for providing data and information services to support the global change research community.
Although much of the development has been in anticipation of the future launch of the EOS instruments (MOPITT being one of the five instruments scheduled to be launched in 1998 on board of the EOS AM-1 satellite), each of the DAACs now has accumulated significant data holdings, mainly from previous satellite expeditions.
Historically it has been difficult for scientists conducting interdisciplinary research to locate useful data, because it was necessary to contact many different data centers regarding data holdings and availability. The Version 0 Information Management System (V0 IMS) is a prototype system designed to overcome such difficulty by allowing a user to search for and order data from any DAAC, or a combination of DAACs, in a single on-line session. Based on Client-server computing technology, the V0 IMS will accomplish one of the goals of EOSDIS: To make global change research data more visible and accessible for interdisciplinary research.
The V0 IMS is now available free of charge to the scientific community. This article serves as a brief introduction to the V0 IMS for users who would like to know more about the functionality of the V0 IMS and how to install the V0 IMS on their own computer. For more detailed descriptions, readers are referred to the following documentations:
(1) EOSDIS Information Management System, Users Manual. by Hughes STX Corporation,
November 1994.
(2) V0 IMS Installation Guide (client and support files). by NASA Goddard Space Flight Center,
June 15, 1995.
In addition to the capabilities provided by V0 IMS, some DAACs will have individual on-line systems, allowing them to provide unique services for users of a particular type of data. These "DAAC-unique" systems will look and function much like the V0 IMS, but will emphasize products or services specific to that DAAC.
There are a number of different agencies and data centers cooperating within the MTPE framework to make data more accessible. One example of this cooperation within EOSDIS is the Satellite Active Archive (SAA) developed by the National Oceanic and Atmospheric Administration (NOAA). The SAA is searchable using V0 IMS in the same way as are the DAACs. In addition, USGS data at EDC and CDIAC data at ORNL are visible through the V0 IMS. Listed below are the DAACs and the SAA with their subject area.
DAAC Name Scientific Discipline
ASF DAAC Polar Regions and
Alaska SAR Facility SAR Data
EDC DAAC Land Processes
EROS Data Center
GSFC DAAC Upper Atmosphere
NASA Goddard Space Global Biosphere
Flight Center Atmospheric Dynamics
Geophysics
JPL DAAC Physical Oceanography
NASA Jet Propulsion
Laboratory
LaRC DAAC Radiation Budget
NASA Langley Tropospheric Chemistry
Research Center Clouds and Aerosols
MSFC DAAC Hydrologic Cycle
NASA Marshall
Space Flight Center
NSIDC DAAC Snow and Ice
National Snow Cryosphere and Climate
and Ice Data Center
ORNL DAAC Biogeochemical
Oak Ridge Dynamics
National Laboratory
SEDAC Human Impact on
Socioeconomic Data Global Change
and Applications Center
NOAA SAA Satellite Remote Sensing
Satellite Active Archive
The V0 IMS provides a consistent view of data sets held at EOSDIS data centers, allowing users without specific prior knowledge of the data to search science data holdings, retrieve high level descriptions of data sets and detailed descriptions of the data inventory, view browse images, and place orders for data. In short, the V0 IMS is designed to provide users with a "one-stop shopping" tool for archived data.
Directory Information for DAAC Data Sets
The Directory provides brief concise high-level information about data sets from
any point in the system.
Guide Subsystem
The Guide provides detailed descriptions about data sets, platforms, sensors, projects,
data centers, and includes algorithm descriptions and calibration information.
Inventory
The Inventory Search function provides descriptions of specific observations or collections
of observations of data (granules) that are available for request from a data center.
Coverage Maps
The Coverage Map is a two-dimensional graphical representation of the geographic
coverage of selected inventory granules. It displays the Earth in an orthographic
projection.
Browse
The Browse function allows a user to locate and retrieve reduced resolution images as an
aid to data selection. The user may either view the image in the IMS interface or have it
staged for FTP pickup.
Order Data
This function allows users to view information pertaining to orderable data products, and
then construct a request which is forwarded to the relevant archive for order processing.
Access to Global Change Master Directory
The Global Change Master Directory (GCMD) is a multidisciplinary data base of
information about Earth and space science data. It contains high level descriptions
of data set holdings of various agencies and institutions.
Character User Interface
The Character User Interface (ChUI) is intended for users who do not have access to an X-terminal, have a small monitor screen, or are accessing the system via low-bandwidth communications (e.g. via modem). Although it is designed to run on a VT100-standard terminal, it also operate on VT2xx- and VT3xx-class terminals, as well as other terminals that support VT100 terminal emulation. ChUI is an old type of interface, and is now being phased out and replaced by the WWW user interface.
Graphical User Interface
The Graphical User Interface (GUI) is a graphical environment which operates under the X-window system, allowing the user to display multiple windows simultaneously, and supports a mouse for easy user interaction. It combines the most sophisticated capabilities among the three existing interfaces offered so far by the V0 IMS. It also allows search areas to be specified from a global map, and provides an interactive data browse facility and coverage map of data products.
In order to run the GUI, the hardware display device must be able to run the X Windows System and communicate over the Internet. The software targets a 1024 x 768 resolution screen. The minimum number of supported color planes is eight, and monochrome monitors are not supported. A standard X terminal can be used, as well as any personal computer with a compatible X server or emulator.
The following X-Window emulators have been used successfully for the GUI client:
WWW User Interface
The WWW User Interface is the latest development in the V0 IMS system, which is still in the rapidly evolving stage. It provides many of the capabilities of the GUI, but allows users who do not have access to X-Window, or who do not need the full capability of the GUI IMS, to search for V0 data regardless of platform using a WWW browser. The WWW interface is available at the following URL: http://eos.nasa.gov/imswelcome
Here we only provide some additional useful information and tips to help users understand the installation process, which turned out to be a non-trivial exercise. Some tips only apply to the installation of a GUI interface.
The binary port is a core part of the V0 IMS, which includes binary executable files for either GUI or ChUI interface (under a subdirectory bin) and client support files (under a subdirectory lib). The source port will add two more subdirectories ims and public to form a complete V0 IMS Client. The subdirectory ims contains all the source code related to the V0 client. And public contains several third party packages used by the V0 IMS Client.
The source port is considerably more complex. Space needed for the third-party libraries is about 40 MB. And Client source code including .c and .o files requires roughly 17 MB. By adding 12 MB for binary and support files, a minimum of the disk space for a V0 IMS Client port is about 70 MB.
As far as RAM is concerned, at least 32 MB of RAM or preferably more is required. The client uses a lot of memory, particularly when large result sets are returned.
(1) Anonymous FTP:
Users can type the following command to log on to a designated site:
ftp killians.gsfc.nasa.gov
Enter "anonymous" as a user name and your own e-mail address as a password. When you successfully log on to killians, get down to a directory /dist/dist, under which there are four separate subdirectories: binaries, lib, public and ims. They correspond to the four directories we introduced for the binary port and source port. Under each of these subdirectories, the user can fetch the corresponding files, which are all compressed tar files.
It should be noted that under binaries the user needs to choose a platform corresponding to the computer machine they will install the V0 IMS Client. As mentioned before, the currently supported machines are SGI Irix 4, SGI Irix 5 and SunOS 4.1.3. There are individual subdirectories under binaries for each of these machines.
(2) Transfer through WWW:
To download files through the WWW, go to the EOSDIS home page by using the following URL:
Then, click a hyperlinked item called "Download the V0 IMS Graphical User Interface (GUI) Client" to get into a new page. You could choose Version 4.5 or Version 5.0.3 software for your particular computer system. Download is done on-line and some browser could uncompress the tar files as the files are downloaded.
V0 IMS Installation Guide (client and support files) gives a step-by-step guide to compiling these individual libraries. This document is available through the World Wide Web as
The user may encounter different problems during compilation depending on the computer platform of their choice. Most of the problems arise due to missing include files and/or lack of proper options in the makefile.
It was our experience that the colour setting was an important factor for running the V0 IMS properly through the Hummingbird X-Window emulator under the Windows 3.1 environment. A choice of 256 colours setting works fine with the V0 IMS, while 65,536 colours setting will result in errors in I/O address.