PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT INTERCHANGE_FORMAT = ASCII PUBLICATION_DATE = 2000-05-13 END_OBJECT = TEXT END Volume CL_2108 Clementine Bistatic Radar Intermediate and Reduced Data Archive (CLEM1-L-RSS-5-BSR-V1.0) AAREADME.TXT R.A. Simpson Stanford University ============================================================================== INTRODUCTION ============================================================================== This compact disc contains archival data produced during analysis of Clementine bistatic radar observations at Stanford University. Raw data were archived earlier as data set CLEM-L-RSS-1-BSR-V1.0 and contain measurements from seven Clementine orbits of the Moon. This data set is primarily limited to data from Orbit 234 (also known as Revolution 233) with special emphasis on data collected between 18:36:45 and 18:52:45 UTC on 1994-04-09. Nozette et al. (Science, 274, 1495-1498, 1996) argued that these data showed possible presence of water ice deposits near the lunar South Pole. The Stanford analysis (Simpson and Tyler, J. Geophys. Res., 104, 3845-3862, 1999) was unable to reproduce the Nozette et al. results. The 16 minutes of data collected between 18:36:45 and 18:52:45 were corrected for instrumental effects and calibrated to the same amplitude standard in several processing steps. The same processing was applied to both right-circularly polarized (RCP) and left-circularly polarized (LCP) data. Each disc in the volume set contains one 384 MByte file from this processing. Files containing calibration data for each polarization are stored in the CALIB directory. For interpretation, grids of geometrical parameters, Doppler shifts, and predicted echo amplitudes were generated for a South Polar orthographic projection of the surface. Sixteen grids were calculated at each of 100 second time steps; these have been saved as PDS IMAGE objects. Each volume contains grids from 8 consecutive time steps. Because one grid is computed by differencing another, there are only 15 grids at the first and last time steps. The final volume contains grids at only 3 time steps. The final volume also contains echo measurements sorted and then aggregated into empirical scattering functions. The scattering functions show no discernible peak in echo power as the bistatic angle passed through 0 degrees near the South Pole -- the expected behavior had significant exposures of clean water ice been present. The volumes and (briefly) their contents are listed below: VOLUME_ID Partially Processed Data File Time Steps of Grids (seconds from 0h UTC) --------- ----------------------------------- --------------------- CL_2101 RCP Time Samples after Equalization 65696-66396 CL_2102 LCP Time Samples after Equalization 66496-67196 CL_2103 RCP Gain Corrected Time Samples 67296-67996 CL_2104 LCP Gain Corrected Time Samples 68096-68796 CL_2105 RCP Samples with Carrier Centered 68896-69596 CL_2106 LCP Samples with Carrier Centered 69696-70396 CL_2107 RCP Samples with Pole Bin Centered 70496-71196 CL_2108 LCP Samples with Pole Bin Centered 71296-71496 Volume CL_2108 also contains measured values of echo power sorted and aggregated into empirical scattering functions. ============================================================================== VOLUME SET INFORMATION ============================================================================== This disc is one of eight which contain partially processed and reduced data from Clementine bistatic radar observations. Each archive volume has the structure illustrated in the diagram below. Not all directories are included on every disc; for example, only the last volume has SORT data. In cases where the directory would contain no files, the directory itself has been omitted from the CD-WO volume. Data are grouped in the volume set roughly in the order that the files were produced within a single data type. Partially processed time samples appear in the volume set (in the DATA directory) in the order: equalized, gain corrected, carrier centered, and pole bin centered. Within any processing step, the RCP file appears on an earlier volume than the corresponding LCP file. Grids of geometrical, Doppler, and signal strength parameters appear in time order in the IMG directory within the volume set. The SORT directory (containing the most highly processed data) appears only on the final volume. Ancillary, calibration, and documentation files are repeated on each volume in the CALIB, CATALOG, DOCUMENTATION, and GEOMETRY directories. The EXTRAS directory also appears on each volume; it contains a single non-essential document not available in ASCII format. root | |- AAREADME.TXT |- ERRATA.TXT |- VOLDESC.CAT | |- CALIB | | | |- CALINFO.TXT Overview of directory | |- FL14SR01.SPC DSS 14 RCP filter #1 | |- FL14SL01.SPC DSS 14 LCP filter #1 | |- FL14SR02.SPC DSS 14 RCP filter #2 | |- FL14SL02.SPC DSS 14 LCP filter #2 | |- FL43SR01.SPC DSS 43 RCP filter #1 | |- FL43SL01.SPC DSS 43 LCP filter #1 | |- FL43SR02.SPC DSS 43 RCP filter #2 | |- FL43SL02.SPC DSS 43 LCP filter #2 | |- TABLE2.TAB System temperature calibrations | |- G099C141.TAB DSS 14 RCP gain correction coefficients | |- G099C143.TAB DSS 14 LCP gain correction coefficients | |- STEERCF1.TAB Carrier frequency coefficients | `- DF2SCM.TAB South Pole bin frequency coefficients | |- CATALOG | | | |- CATINFO.TXT Streamlined PDS templates | |- MISSION.CAT for mission, host, | |- INSTHOST.CAT instrument, references, | |- INST.CAT personnel, data set, and | |- REF.CAT data set map projection | |- PERSON.CAT | |- DATASET.CAT | `- DSMAP.CAT | |- DOCUMENT | | | |- DOCINFO.TXT Overview of directory | |- DSS14PRF.TXT DSS 14 antenna performance | |- DSS14TSY.TXT DSS 14 system temp measurements | |- DSS43RPT.TXT DSS 43 data overview | |- DSS43TSY.TXT DSS 43 system temp measurements | |- FNDO.TXT Stanford FND format description | |- LPSC_ABS.ASC LPSC XXXI abstract (ASCII) | |- LPSC_ABS.PDF LPSC XXXI abstract (PDF) | |- MOON_CAL.TXT Moon Tsys calibrations | `- PROCSSNG.TXT Processing description (comprehensive) | |- EXTRAS | | | |- EXTRINFO.TXT Overview of directory | `- OFFSQNT.PDF RCP vs LCP Pointing at BWG antennas | |- GEOMETRY | | | |- GEOMINFO.TXT Overview of directory | |- BSRGEOM.TAB Summary of observing geometry | |- BETAZERO.TAB Listing of 'targets' (radians) | `- BETAZER1.TAB Listing of 'targets' (degrees) | |- INDEX | | | |- INDXINFO.TXT Overview of directory | |- INDEX.TAB Index for current volume | `- CUMINDEX.TAB Cumulative index for all volumes | |- IMG- Directory of gridded data as images | | | |- sssssppp.IMG Image for time sssss of parameter ppp | |- tttttqqq.IMG Image for time ttttt of parameter qqq | |- ... | `- uuuuurrr.IMG Image for time uuuuu of parameter rrr | |- DATA Partially processed time samples (one | | file per volume) | `- XXc.TAB Output file of XX data for channel c | where XX is | PF - equalized data (program PREPFND) | GN - gain corrected (program GAIN) | S1 - carrier-centered (program STEER) | S2 - Pole bin centered (program STEER) | and c is | 1 for RCP | 3 for LCP | `- SORT Sorted and aggregated data (CL_2108 only) | |- RCP.IMG Core RCP echo spectra |- LCP.IMG Core LCP echo spectra |- SRTPWRR.TAB RCP echoes sorted by target, beta |- SRTPWRL.TAB LCP echoes sorted by target, beta |- SRTNPWR.TAB Number of echoes per target, beta `- RATIOFN.TAB Empirical scattering functions ============================================================================== ERRATA ============================================================================== A cumulative list of errors and changes is maintained in the file ERRATA.TXT at the root level of each volume. ERRATA.TXT on volumes produced later will list errors on the earlier discs. ============================================================================== DISC FORMAT ============================================================================== The disc is organized according to the PDS standard for "one data set, many volumes." This file (AAREADME.TXT), a PDS volume object definition (VOLDESC.CAT), and the listing of errors and changes (ERRATA.TXT) are included at the root level. The following directories of descriptive material are also at the root level: CALIB contains tables of calibration data used in correcting sample amplitudes, adjusting signal frequencies, and determining absolute power levels in the two channels CATALOG contains descriptive files for cataloging the data included in this disc. DOCUMENT contains plain text descriptions of data formats, processing, and calibration. EXTRAS contains a single non-essential document describing polarization dependent offsets in pointing of DSN beam-waveguide antennas. GEOMETRY contains summary tables of observing geometry and lists of 'targets' in the south polar region used to construct empirical scattering functions. INDEX contains index information on each of the data files included in this disc; it also includes a cumulative index to all files in this volume set. The remaining directories at the root level (DATA, IMG, and SORT) contain data files and detached PDS labels. ============================================================================== FILE FORMAT ============================================================================== With the exception of PDS TEXT objects, all files on the disc are accompanied by detached PDS labels, which describe their contents. PDS TEXT objects (suffix TXT) include attached labels. Detached labels have the same file name as the primary data file except for the suffix ".LBL". In PDS DOCUMENT objects a single label may accompany two versions of the document (for example, an ASCII version and a PDF version). Text files, including data files of ASCII text and all labels (*.LBL files) and tables (*.TAB files), are delimited by carriage-return (ASCII 13) line-feed (ASCII 10) pairs at the end of each line. ============================================================================== ACKNOWLEDGMENTS ============================================================================== Descriptions of the Clementine spacecraft, and especially its radio system, were provided by Chris Lichtenberg of the Clementine Project, who was also the experiment Principal Investigator and oversaw spacecraft operations during experiment periods. Sami Asmar provided the interface with the NASA Deep Space Network during the experiment period. The JPL Radio Science Support Team provided open-loop (ODR) data from the experiment. The JPL Navigation and Ancillary Information Facility provided trajectory and attitude files for the spacecraft. The orbit solutions were generated by Frank Lemoine of Goddard Space Flight Center. Valerie Henderson as interface to the Central Node of the Planetary Data System. Some facilities provided by the Mars Global Surveyor Project were used on a non-interference basis in producing this archive. ============================================================================== DISCLAIMER ============================================================================== Although considerable care has gone into making this volume set, errors are both possible and likely. Users of the data are advised to exercise the same caution as they would when dealing with any other unknown data set. Reports of errors or difficulties would be appreciated. Please contact one of the persons listed below. ============================================================================== COGNIZANT PERSONNEL ============================================================================== The person most directly responsible for construction and release of this volume set is Richard Simpson, Experiment Engineer for the Mars Global Surveyor (MGS) Radio Science Team (RST) and Radio Science Advisor to the Planetary Data System. Although many people contributed to the volume set, any faults in the product are his alone. Richard A. Simpson Center for Radar Astronomy Packard Bldg - Room 332 Stanford University Stanford, CA 94305-9515 Tel: 650-723-3525 FAX: 650-723-9251 rsimpson@magellan.stanford.edu