***** File AAREADME.TXT This compact disc (CD-ROM) contains a revised version of the comet Giacobini-Zinner (P/G-Z) test archive produced by the International Halley Watch (IHW) in cooperation with the National Space Science Data Center (NSSDC). The CD-ROM also contains the comet Crommelin archive produced by the IHW. This disc (which has the volume id. HAL_0024) is included in the larger set of discs containing the comet Halley archive. There is a mixture of data types on this disc that comprises 3739 (ground-based) observation files (or 132 MByte) of P/G-Z and 680 observation files (or 39 MByte) of P/Crommelin. In addition, there are 25 calibration files for P/G-Z and 15 calibration files for P/Crommelin included. The data acquired on P/Crommelin during its 1983-84 apparition were part of a trial run of the IHW organization. Since this first effort by the IHW wasn't originally intended for inclusion on a CD-ROM, the more sophisticated aspects of archiving on CD-ROM (utilized for the P/G-Z and P/Halley archives) are not included for P/Crommelin, e.g. there are no PDS labels included, the FITS headers have not been detached from the data record files, the indices included are more primitive and fewer, etc. The campaign to gather observations of the 1984-87 apparition of P/G-Z was begun by the IHW to support the NASA mission that sent the International Cometary Explorer spacecraft through the comet tail on September 11, 1985. (The results from most experiments on that mission have been archived by the NSSDC and are provided together with the spacecraft data acquired about comet Halley on other volumes in the complete CD-ROM set.) This file is the only text file that is located in the Root directory. A listing of the contents of the subdirectories for the CD-ROM follows: BROWSE - subsampled Large Scale Phenomena browse images (of P/G-Z) ordered chronologically CALIB - supplemental data (plus headers) COMPRESS - compressed images (of P/G-Z; Previous Pixel algorithm), ordered chronologically DOCUMENT - supporting text files EPHEM - ephemeris data for comet INDEX - delimited tables for locating data SOFTWARE - supporting source and executable code One directory for each IHW discipline containing complete FITS files in chronological order (for P/Crommelin) as well as associated directories for CALIB, EPHEM, INDEX and DOCUMENT Chronological directories with FITS headers, data record files, and PDS labels ordered by time (for P/G-Z): * 1984 - year only * 1985 - year, month, day, or half day (00 or 12 hours period) * 1986 - year only * 1987 - year only An illustration of the subdirectory structure of this CD-ROM is given in the file, CDTREE.TXT, located in the DOCUMENT subdirectory. Note that all explanatory files are ASCII text (.TXT) with characters at the end of each line. To show special content some files have been given extensions as follows: .APX - Appendix (text) files .C - C source code .COM - executable file (MS-DOS) .EXE - executable file (on this disk, either VAX/VMS or MS-DOS) .FOR - Fortran source code .HHH - ASCII version of FITS header file .IDX - delimited table files .PRO - IDL procedure file .TXT - text (documentation and information) files The use of other file extensions (particularly in the INDEX subdirectory) is considered to be a common practice for dBASE III files, e.g., DBF and STR. Other file extensions used to document the data are described by various text files FITSFORM, HDRFORM, IMAGFORM, LBLFORM, SPECFORM, TABLFORM, and TEXTFORM. Specialized information about other subdirectories is given in the files listed below: BRWZINFO.TXT - discusses the browse files (of P/G-Z) and their structure CALINFO.TXT - lists the groups of supplemental files (for P/G-Z) COMPINFO.TXT - lists the compress files CR_CALIB.TXT - lists the groups of supplemental files (for P/Crommelin) CR_EPHEM.TXT - explanation of the ephemeris for P/Crommelin CR_INDEX.TXT - description of how to use the table data (for P/Crommelin) EPHEM.TXT - explanation of the epehemeris for P/G-Z INDXINFO.TXT - description of how to use the table data (for P/G-Z) SOFTINFO.TXT - listing of the software information supplied There are two special text files in the DOCUMENT directory that give an overview of the P/G-Z archive (GZGUIDE.TXT) and the P/Crommelin archive (CROMGUID.TXT), respectively. In addition, the file CDSTRUCT.TXT is a listing of every file on the disc. It has been used to construct an inventory file in the root directory (VOLDESC.SFD) following guidelines of the Consultative Committe on Space Data Systems for machine access. For more information about the use, content, or structure of the CD-ROM, please contact one of the following: M. Aronsson E. Grayzeck, Jr. A. Warnock III IHW Lead Center Small Bodies Node IHW Large Scale Planetary Data System Phenomena Network (LSPN) Mail Stop 169-237 Astronomy Program ST Systems Corp. NASA/JPL University of Maryland Code 681 4800 Oak Grove Dr. College Park, MD 20742 NASA/Goddard SFC Pasadena, CA 91109 Greenbelt, MD 20771 SPAN: JPLSC8::MIK SPAN: CHAMP::GRAYZECK SPAN: CHAMP::WARNOCK or Internet: or Internet: or Internet MIK@SCN6.JPL.NASA.GOV GRAYZECK@ASTRO.UMD.EDU WARNOCK@STARS.GSFC.NASA.GOV