[Spice_announce] Some announcements and questions
Charles H. Acton
Charles.H.Acton at jpl.nasa.gov
Fri Jul 18 17:08:56 PDT 2008
This message contains several announcements and questions.
Merged SPICE Tutorials
--------------------------------------------------------------
A few of you have asked for an integrated package of the SPICE
tutorials. We took this to mean a single PDF file. That is now
available under the Tutorials web page (see the bottom entry,
SPICE_Tutorials_Merged") at the NAIF website:
http://naif.jpl.nasa.gov/naif/tutorials.html. This is an 800+ page
PDF file.
FURNSH Kernels for Archived SPICE Data Sets
--------------------------------------------------------------
A few months ago NAIF began providing so-called FURNSH kernels for
the PDS archived SPICE data sets. A FURNSH kernel, sometimes called a
meta-kernel, provides a convenient listing of all* the SPICE kernels
that should be used together for a stated mission period. For some
missions the breakdown is by calender year, while for others there is
a single FURNSH kernel covering the entire mission.
Your application program need "load" only the FURNSH kernel(s) for
the period(s) of interest and this will automatically load all of the
individual SPKs, CKs, etc. that apply to that period. (This assumes
you have downloaded the entire SPICE data set and have modified the
value assigned to the PATH_VALUES keyword to point to the actual
location of the SPICE data set's /data directory on your computer!)
These FURNSH kernels are placed in the /extras/mk folder within each
archived data set. For instance, for the SPICE data that have been
formally archived for the Cassini-Huygens mission, the collection of
FURNSH kernels is found here:
ftp://naif.jpl.nasa.gov/pub/naif/pds/data/co-s_j_e_v-spice-6-v1.0/cosp_1000/extras/mk/
Should circumstances require a given FURNSH kernel be updated, a new
version is created. An improved trajectory file is an example of such
an update.
If you are unfamiliar with the notion of a FURNSH kernel, please
download and read pages 13-15 of the "Introduction to Kernels"
tutorial. This is a capability with which all SPICE users should be
familiar.
*NOTE: Cassini-Huygens is a special case. Only for this mission (so
far) was NAIF unable to select a complete set of kernels for a given
period of time. For Cassini it is not clear to NAIF which PCK a
particular customer would want to use, given that Cassini updated the
PCK with every new spacecraft trajectory solution.
Improved Information about PDS Archived SPICE Data Sets
--------------------------------------------------------------
Until now anyone wishing to access the formally archived SPICE data
for a given mission had to either know where to find it on the NAIF
server using the FTP protocol, or, get to it through a Planetary Data
System central catalog interface that turns out not to be very
convenient for acquiring a complete archived SPICE data set.
A new web page has been added that improves the connection to all
archived SPICE data sets, including providing information about the
dates covered and the size of the data set in Mbytes.
This change is part of a broader set of changes to the NAIF "Data"
web pages aimed at better explaining what data are available.
If you have occasion to try these web pages, we're interested in your
feedback on what works and what doesn't--how might we further improve
your access to SPICE kernels?
Interoperability of Ancillary Data on an International Scale?
--------------------------------------------------------------
This week it is possible that the international group known as
Committee on Space Research (COSPAR) will have endorsed the
activities of the fledgling International Planetary Data Alliance
(IPDA) http://www.planetarydata.org/, which is aimed at establishing
interoperability among planetary science data archive systems. The
primary focus of the IPDA will understandably be on science
instrument data... images, spectra, particle counts, etc. But should
the IPDA be encouraged at some future date to take up the question of
standards and mechanisms for achieving interoperability across
whatever ancillary data systems are used by the various participating
nations/agencies? Should you have any thoughts on this topic you are
encouraged to contact the current IPDA chairperson, Maria Teresa
Capria, or any of the IPDA members. Contact information for these
people may be found at: http://www.planetarydata.org/Members.
Consider sending a copy of your thoughts to the NAIF manager
(charles.acton at jpl.nasa.gov).
A Public SPICE Tools Repository?
--------------------------------------------------------------
If you are reading this text you are probably rather familiar with
the kinds of tools (application and utility programs) the NAIF Group
provides in the SPICE Toolkits, and the few extra tools available
only from the utilities link on the NAIF webpage. This rather tightly
controlled situation is not likely to change, other than NAIF will
slowly add hopefully useful new tools as time permits.
Perhaps some of you SPICE users have developed, or might develop,
tools you'd be willing to share with other SPICE users, either as
supported code or in an "you're-on-your-own" basis. Anyone have any
thoughts on this topic?
Might it be useful?
Portability issues?
Accuracy/correctness issues?
How maintain compatibility with SPICE Toolkits?
ITAR issues?
Liability concerns?
Intellectual property rights issues?
Where hosted? (Is there an existing site that would work?)
How would it work?
Might such a repository also include APIs (subroutines)?
If you have comments/ideas either send them to the NAIF manager
(charles.acton at jpl.nasa.gov) or, for broader viewing and feedback, to
the spice_discussion Mailman list
(spice_discussion at naif.jpl.nasa.gov).
Finally, don't forget....
--------------------------------------------------------------
See the NAIF home page (http://naif.jpl.nasa.gov/naif/pds.html) for
announcements about the new leapseconds kernels (LSK) and the
upcoming SPICE training class.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://naif.jpl.nasa.gov/pipermail/spice_announce/attachments/20080718/19e9457f/attachment.html
More information about the Spice_announce
mailing list