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Frequently Asked
Questions
If you don't see your question here, check the
Geosciences Node
Forums
to see if it's been discussed there. There are
forums for announcements, data users, data providers,
Analyst's Notebook users, and Orbital Data Explorer
users. You may post your question in one of the forums
(after signing up for a free account), or you may email
it to
geosci@wunder.wustl.edu.
What is PDS?
PDS is the Planetary Data System, a
NASA-funded organization that archives and distributes
planetary data to the science community. It exists as a
geographically distributed set of Nodes, each
responsible for a particular kind of data. Read more on
the Background
page at this site and on the
PDS Home Page.
How much does it cost to obtain PDS
data?
Data sets archived in the PDS are in
the public domain. Almost all PDS data sets are online
and may be downloaded by anyone for free.
Can I use FTP to download data?
Yes. Read about
Anonymous FTP Access.
What if the data set I want is
not online?
Ask the PDS Node responsible for the data set to
put it online for you.
What if the data set I want is too big to
download?
Ask the PDS Node responsible for the data set
whether you can receive the data another way. For
example, the Geosciences Node can sometimes ship data
on a user-provided disk drive.
I downloaded some files but I think they may have been corrupted during the transfer.
How can I tell?
Compare the checksums of the files on your end to the checksums on the
Geosciences Node server.
Read more about checksums here.
Are there any restrictions on the
use of PDS data?
PDS data sets are classified TSPA
(Technology and Software Publicly Available) by the
U.S. Department of Commerce, Bureau of Export
Administration, and may be exported outside the United
States as public open literature. When PDS data sets
are used in published literature or other
applications, they should be cited appropriately (see
below).
Documents in PDS archives are also freely
available for downloading. Documents by JPL authors
may carry a copyright statement, which is not
intended to restrict access. These documents are
covered by the JPL Data and Documentation Use Policy
for PDS.
How should PDS data sets be cited in
scientific literature?
PDS data sets should be cited in the same way that
published research is cited. See
Citing PDS Data on the general PDS web site.
I don't understand the archives I see online. What
are all these files?
Please read
Help for Data Users,
which explains the standard structure
followed by all PDS archives.
How do I display a PDS image?
A PDS image is stored as a binary
array with a plain-text PDS label either embedded at
the beginning of the file or in a separate file. The
label has all the information needed to enable image
display programs to read and display the image.
NASAVIew is a free program from PDS that will display
a PDS-labeled image. PDS deliberately does not use any
commercial or proprietary formats to archive image
data, in order to ensure the long-term viability of
the data.
I have heard that PDS does not archive data that
have been compressed, as in JPEG images. Why not?
In general data products that have been lossy-compressed
-- that is, compressed in such a way that some of the
original data are not recoverable -- are not suitable
for PDS archives. There are exceptions. Please read
the
Policy for Use of Compression in PDS Archives.
Sometimes compressed data such as JPEG images may
appear in an archive but not as the primary archive
product.
I have been asked to help review a
new PDS data set. What do I do?
The input of peer reviewers is very
important to us. Please read the
Help for Data Reviewers,
and if you still have questions, email us at
geosci@wunder.wustl.edu.
I am writing a proposal that includes using PDS
data and/or submitting new data to PDS. What do I do?
Please read
Help for
Proposers for some guidelines.
I have some questions about LOLA data from the Lunar
Reconnaissance Orbiter mission.
Visit the
LOLA Frequently Asked Questions page.
Last updated March 28,, 2013.
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