- What is NTRS?
The NASA Technical Report Server is an experimental service that allows users
to search the many different abstract and technical report servers maintained
by various NASA centers and programs. Specifically, it is a unified interface
to many separate WAIS servers. NTRS is both a superset of the
of the various servers, and a canonical listing of the servers.
- Who can use NTRS?
NTRS is intended for use by the various research communities targeted by
the various report and abstract servers. It is open to all members
of the Internet/World Wide Web community.
- Who can participate in NTRS?
Any NASA center, NASA affiliated research institute, or NASA program or subject
area with scientific data, reports, or other information may participate.
Contact Michael Nelson (m.l.nelson@larc.nasa.gov) for more details.
- Why do the searches take so long?
The various databases that comprise NTRS are not centrally located; each
one is stored on a different computer on the Internet. While it appears
that NTRS is searching 1 machine, it is actually searching many. So the
more databases you select, the more time delay you are likely to experience.
Also, it is possible for any one of the NTRS machines to be down at a
given time. While we strive to avoid this, it will certainly happen from
time to time, and an additional delay will be experienced.
- I'm having difficulty with one of the reports...
Please contact the person(s) responsible for that document. For example,
do not contact Dryden Flight Research Center personnel if you have
difficulty with a Langley Research Center document. The
NTRS Team
lists the points of contact for each database.
- What are some of the odd characters in the abstracts?
Some of the abstracts have TeX artifacts (i.e., remnants of math symbols).
Other abstracts may have been scanned in, and the OCR (Optical Character
Recognition) software may have introduced spurious characters.
- How do I print the reports on a Macintosh?
If you are Macintosh user, Manny Salas has a good summary page of
processing compressed, PostScript files on a Mac.
Unless you are using Netscape or another browser that knows to invoke
MacGzip when it sees a .Z file, you will probably have to use the
"load to local disk" option, (or "binary transfer", or "save next link
as") to tell the browser to just move the file, and not try to interpret it.
- My searches are often inconsistent - how do I make them better?
General tips for better searching:
- There is an implicit logical "OR" operator. Thus, a search for "turbulent
flow" is the same as a search for "turbulent OR flow", which
may or may not be what you intend.
- The logical operators "AND" & "NOT" are available. Instead of searching
for "global positioning system", you will get more meaningful results by
searching on "global AND positioning AND system".
- Spell your search words correctly - there is no "fuzzy" searching of key terms.
- No stemming is done. Thus, to match both "turbulence" and "turbulent", search for "turbule*".
- The dash character``-'' separates words. So the search term STS-60 will reveal search for (``STS'' or ``60''). To have it interpreted as
a single term, put double quotes around the term: "STS-60". Note: this quoting method will not work on the CASITRS/RECONselect and SCAN databases, due to server
differences. We will attempt to rectify this problem.
- The more keywords entered, the more likely you are to have a successful search (Note: Unless you are "AND"ing your search terms!)
- If some databases in NTRS are obviously not applicable, don't waste
bandwidth (and your time) searching them. Turn them "off" by toggling the
button to the left of their name.
- How do I know which databases to search?
The various databases cover many subject areas, but here are some
rules of thumb:
- General Aerospace and Related Fields: CASITRS/RECONselect, SCAN and the various centers'
databases (Dryden, Langley and Lewis)
- Computer Science: ICASE and NAS
- Astronomy and Astrophysics: ADS, GISS, STELAR
- Atmospheric and Earth Sciences, global change: GISS
Remember to click/check/select the box to the left of the database names
to select which servers to search or not to search.
Please remember that most of the databases represented in NTRS are
experimental. Thus, not all of NASA's research activities are represented.
- How many reports are in each database?
This is subject to change at any time, but the following are provided as
ball park figures:
- LaRC - 500+ reports
- Numerical Aerodynamic Simulation Division (NAS) - 110+ reports
- ICASE - 110+ reports
- DFRC - 26 reports, 640+ abstracts (reports are being added incrementally)
- GISS - 28 reports, 440+ abstracts (reports are being added incrementally)
- LeRC - 3 reports, 920+ abstracts (reports are being added incrementally)
- CASITRS/RECONselect - 1,000,000+ abstracts
- ADS - 160,000+ abstracts
- STELAR - 75,000+ abstracts
- SCAN - 1000's of abstracts (contents regularly replaced)
- What about copyright, FEDD, ITAR and other issues?
In general, government work is not copyrighted. This includes reports and
articles that may be published elsewhere but have US government authors.
NASA has an agreement with the AIAA that allows them to copyright NASA work,
but NASA retains the rights to their material, and may distribute it as
appropriate.
There are only ``unclassified, unlimited'' reports on this server. FEDD
documents will only be made available after the restriction period is over.
NTRS is available to researchers world-wide, and the content is never more than
what researchers world-wide could obtain through conventional channels.
- Where can I find NACA reports?
There is currently no large collection of Internet accessible NACA reports.
There are some NACA report scanning and CD-ROM projects, and if their output
is easily gated to the World Wide Web, we will attempt to add them to NTRS.
- When will CASITRS/RECONselect and other abstract services have full-text available?
Due to the wide range of sources that services like
CASITRS/RECONselect draw from, it is difficult to define a method
to obtain electronic copies of documents. The issue is being
addressed, but the exact date of such service is unknown.
There is also the issue of copyright. Only US goverment authored
work is copyright-free, so serving copyrighted work will most
likely involve some prior negotiation or charge back mechanism.
- Are other tech report servers available?
Yes. The URL http://www.larc.nasa.gov/org/library/abs-tr.html contains a list of servers.
- Where do I order a hardcopy of the report?
Contact one of the following:
NASA Center for Aerospace Information (CASI)
800 Elkridge Landing Road
Linthicum Heights, MD 21090-2934
Phone: (301) 621-0390
E-mail: HELP@STI.NASA.GOV
National Technical Information Service (NTIS)
5285 Port Royal Road
Springfield, VA 22161-2171
- Where can I get NASA developed software?
Distribution of NASA software is handled through COSMIC. It is possible that some experimental, non-COSMIC software
distribution mechanisms will appear in the future.
- How can I directly contact a NASA author?
The X.500 service for the NASA hierarchy is good place to start. Please keep in mind that not all authors may be NASA employees
or contractors, and some employees may have left NASA since writing the report.
- Where can I get more info about NTRS?
The URL ftp://techreports.larc.nasa.gov/pub/techreports/larc/94/tm4567.ps.Z
contains the first experiences with report distribution by the LTRS Team, but does not cover the World Wide Web.
The follow up report about LTRS is located at ftp://techreports.larc.nasa.gov/pub/techreports/larc/94/tm109162.ps.Z.
This report details the transition from an FTP server -> WWW. The work covered
here provides the foundation for NTRS.
A paper entitled
The Widest Practicable Dissemination: The NASA Technical Report Server to be
presented at AIAA Computers in Aerospace Conference, San Antonio TX, March 1995 is available and details the artchitecture and components of NTRS. Contact the NTRS Team for more information.
Each database in NTRS is a separate WAIS database. The keywords are taken
from the input box and fed to each of the selected WAIS databases (through
a WWW/WAIS gateway) and the results are collected into a single HTML page.
Only searching is available from the NTRS page; abstract lists and such
must be obtained from the individual report servers.
You can look at user comments about NTRS and the developer's responses.
Please take the time to fill out the NTRS feedback form to let us know what
you think.
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