Index of /volume/hal_0023
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ast_hist/ 17-May-1992 22:07 -
calib/ 17-May-1992 22:07 -
document/ 17-May-1992 22:16 -
ephem/ 17-May-1992 22:16 -
index/ 17-May-1992 22:16 -
ir_filtr/ 17-May-1992 22:16 -
meteor/ 17-May-1992 22:16 -
software/ 17-May-1992 22:16 -
summary/ 17-May-1992 22:16 -
y1987/ 17-May-1992 22:06 -
y1988/ 17-May-1992 22:06 -
y1989/ 17-May-1992 22:07 -
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aareadme.txt 15-May-1992 00:42 11K
acknwldg.txt 12-May-1992 23:50 21K
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voldesc.sfd 17-May-1992 20:57 66K
***** File AAREADME.TXT
This compact disc (CD-ROM) is the last of a 5-disc set containing digital
data obtained through the efforts of all the International Halley Watch (IHW)
Disciplines and their corresponding Networks. Because of their
multi-Discipline composition, the five discs, which are Volumes 19-23 in the
total set of IHW CD-ROMs, have become known informally as the "mixed discs."
Volumes 1-18 are dedicated to the Large-Scale Phenomena Discipline and its
very large image files, which have been deposited on disc in compressed form.
Finally, Volume 24 contains data from the IHW "Trial Run" targets--comets
P/Crommelin and Giacobini-Zinner--and Volumes 25-26 are devoted to space data
returned by the Halley intercept spacecraft and the International Cometary
Explorer (ICE).
This final "mixed disc," which contains the chronologically-last files of
Halley ground-based data, differs from the previous mixed discs (Volumes 19-
22) in a number of ways. First, it serves as a "summary disc" in somewhat the
same way that Volume 18 did for the set of Large-Scale Phenomena discs. To be
specific, the following new directories appear on HAL_0023 (Volume 23):
o CALIB Calibration files broken out by Discipline
o DOCUMENT/OBSVTORY Tables of Observatories & Observing Sites
o IR_FILTER Infrared Filter Curves
o METEOR Entire set of Meteor Discipline Data
o SOFTWARE/BROWSE Source code for constructing L-SP Browse Images
o SOFTWARE/COMPRESS Source code for compressing L-SP Imagery
o SOFTWARE/DECOMP Source code for decompressing L-SP Imagery
o SUMMARY/ERRATA Errata Files for each IHW Discipline
o SUMMARY/INDEX "Quick Look Index" & "Pathtable" for each of 5
"Mixed Discs"
o SUMMARY/OTHER Replacement files for VOLDESC.SFD files on
Volumes 19-22
Although the calibration files also appear in the standard data directories on
Volumes 19-23, chronologically interspersed with the Halley data, it was
thought important to break them out in a dedicated area on the last mixed
disc. Had they been less voluminous, the Infrared filter curve data could
have been placed in that Discipline's Appendix write-up; separate placement on
this disc seemed a good alternative. Although some of the Disciplines
included lists of contributing observatories in their Appendices (deposited on
all 5 mixed discs), only the DOCUMENT/OBSVTORY directory on this disc gathers
all IHW Observatory information together in one place. Data from the Meteor
Studies Discipline is present on all the mixed discs in the form of large
indices (one each for Radar and Visual observations), but only on this disc
are the original FITS headers and table extensions present.
The new software directories listed above include files also deposited on
the L-SP CD-ROMs (Volumes 1-18); they have been included here mostly for
redundancy. Very important are the SUMMARY directories: /ERRATA contains all
information of which we are currently aware concerning errors and
irregularities in this Archive; /INDEX contains corrected versions of each of
the "Quick Look Indices" and "Pathtables" resident on this and the other four
mixed discs; and /OTHER contains replacement files for the VOLDESC.SFD files
of Volumes 19-22, which had truncations in some of the lines. Should an
archive user wish to construct one global quick look index or path table for
the entire IHW Archive (excluding the L-SP data files on Volumes 1-18),
concatenation of the QUIK_0nn.IDX or PATH_0nn.IDX (nn=19-23) files in
/SUMMARY/INDEX would be the way to proceed. The QUIK_0nn.IDX indices on
Volumes 19-22 had some (mostly minor) errors (cf. the file
/SUMMARY/ERRATA/INDXERRS.TXT) which have been corrected in the /SUMMARY/INDEX
versions here; hence the latter should be used whenever possible.
The second way in which this CD-ROM differs from the previous four mixed
discs concerns the documentation: that which is repeated from the other discs
(the majority) has been improved and corrected when necessary, and there are
some completely new files here as well. We cannot emphasize strongly enough
that this CD-ROM, HAL_0023, should be used as the standard source of
documentation and information, the other mixed discs (and this one as well)
serving as the repository of particular data files of interest.
In addition to the "new" directories just discussed, this disc contains a
wide variety of supporting files and tools for the Archive user which are
essentially identical to those on Volumes 19-22; the major categories are
documentation, ephemeris information, searchable tables and indices, and
software (source code as well as executable modules). These have been
organized into four principal directories one level below the root: DOCUMENT,
EPHEM, INDEX, and SOFTWARE. It is suggested that the Archive user review the
document files listed below before roaming through the multi-level data
directories:
/DOCUMENT/HALGUIDE.TXT Brief guide to use of discs
/DOCUMENT/CDTREE.TXT Schematic, annotated layout of disc
/DOCUMENT/VOLINFO.TXT More complete description of disc, history
of IHW CD-ROM generation
/DOCUMENT/APPENDIX/*.APX Appendices for (all) nine IHW Disciplines
/INDEX/INDXINFO.TXT Description of basic indices
/INDEX/NETABLES/NETINFO.TXT Description of "printed archive" and
Discipline-specific indices
/SOFTWARE/SOFTINFO.TXT Brief enumeration of software on disc
The time period covered by this disc is 1987 April 4 -- 1989 April 12.
Data from all IHW Disciplines are included; as on the other mixed discs, the
included L-SP data consist of subsampled, "browse" versions of the much larger
compressed data files deposited on Volumes 1-18. Astrometry data from the
previous apparitions of 1835 and 1910 have been put on this disc, as well as
data from the "current" (1985-86) apparition.
Data preparation for the IHW Archive has been the work of many people
within each Discipline, of the Lead Center personnel at JPL, and of those at
NASA/GSFC who actually generated the CD-ROMs. Efforts at the Discipline level
are described in the Appendix files in the /DOCUMENT/APPENDIX directory, and a
history of IHW CD-ROM generation is given in the ACKNWLDG.TXT file of the root
directory and in the file /DOCUMENT/VOLINFO.TXT. Although many people have
been involved in this project (including the observers), the individuals
listed below were responsible for actually making the discs and they accept
responsibility for any errors in disc format and/or layout, but not actual
file content.
All of the text files on this disc have fixed length records padded to
either 80 or 132 bytes per record. The last two characters of each record are
a carriage return and line feed. This has been done to files with the
following extensions (*.txt, *.str, *.apx, and *.lbl).
M. Niedner, Jr. E. Grayzeck, Jr.
IHW Discipline Specialist Small Bodies Node of
for Large-Scale Phenomena Planetary Data System
Laboratory for Astronomy Astronomy Department
and Solar Physics University of Maryland
Code 684.1 College Park, MD 20742
NASA/GSFC
Greenbelt, MD 20771
D. Klinglesmith III A. Warnock III
IHW Team Member for IHW Team Member for
Large-Scale Phenomena Large-Scale Phenomena
Laboratory for Astronomy Hughes STX Corporation
and Solar Physics Code 631
Code 684.0 NASA/GSFC
NASA/GSFC Greenbelt, MD 20771
Greenbelt, MD 20771
M. Aronsson
IHW Lead Center
Jet Propulsion Laboratory
MS 169-237
4800 Oak Grove Dr.
Pasadena, CA
91109