PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2004-03-31 NOTE = "ERRATA.TXT is an ASCII text file that documents all of the known errors or variances associated with the PDS archive of this volume series. All volumes are included in this list. An updated version of this file is maintained online at the Planetary Plasma Interactions Node of the Planetary Data System. The online errata list can be found on the World Wide Web at the following URL: http://www.igpp.ucla.edu/public/pds/ERRATA/ODYSSEY/ERRATA.TXT " END_OBJECT = TEXT END Volume Error/Variance Description ----------------------------------------------------------------------- All IMPORTANT WARNINGS REGARDING TIME VALUES AND DATA FILE CONTENTS: ODMA_0xxx volumes Some of the raw (REDR) data files contain errors in the time column. These errors include apparent reversals of time sequence (due to out-of-sequence time tags), bad values of the year, and instances in which the onboard clock did not roll over to the next day at midnight. These errors reflect known behaviors of the onboard clock; they are not the results of any fault in data set preparation. In addition, the data files may contain some blocks of records with repeated data. Users who encounter a time reversal in the data should be alert to the possibility that a repeated block of data is beginning, though not all time reversals are due to this cause. To help users identify and work around these problems, the following items have been placed in the reduced (RDR) data files: (1) A corrected time column. This is an altered version of the original time column, which also is present in the reduced data. The original time column is only minimally corrected. The corrected time column represents the result of efforts to compensate for known errors in the original time column. The corrected time column is not guaranteed to be entirely correct. Both time columns should be used critically and with caution. (2) A column of flag values describing problems in the in the time tags or elsewhere in the data. Details on this column are found in the *.FMT files that accompany the data. The second digit of this flag column indicates time reversals. If this digit is 1, then the record either has a time reversal, or occurs within about 10 records after a record with a time reversal. Note that there may be some problems which these flag values do not indicate. (3) Flag values that replace bad values of the year or day in the uncorrected time. (See the *.FMT files accompanying the data for further details.) A few files may lack some of these features (see below). The out-of-sequence time tags have been left in place in the reduced data. This seemed the best policy, since correction or removal of these records might lead to data loss. The great majority of records are not time-reversed with respect to the preceding record. In time tags with flag values for the uncorrected year, the rest of the time tag should be regarded as being of unknown quality. Because of the possibility of time tag problems, users should exercise care when interpreting the time values and when utilizing the time order of any data file or combination of data files. There may be a few files to which the time tag correction and flagging was not applied, because of uncertainty about the correct interpretation of the time tags. Such files will be noted separately in this ERRATA file. For further information, please see the file /DATA/REDUCED/INFO.TXT. OTHER IMPORTANT NOTICES REGARDING THE DATA AND THE DISKS: Before the current release of the reduced data, there were earlier releases, some of which had different data formats, calibration, and file names. The present release should not be confused with any earlier version of the reduced data. Please note that the formats of the reduced data files (under /DATA/REDUCED) may not quite conform to the format described in the DATASET.CAT and the VOLSIS.* document. Specifically, these reduced data files contain a new extra time column and a flag column, as described above. These extra columns are explained in the text file /DATA/REDUCED/INFO.TXT and in the EVT_RDR.FMT files accompanying the data files. They also are explained in /CATALOG/CALIBRATED_DATASET.CAT. Some of the documents in the DOCUMENT directory exist in a PDF version but not in an ASCII version. This exception to PDS standards was permitted because of the infeasibility of converting the original PDF documents to ASCII format. The INDEX.TAB and MANIFEST.TAB files in the current online volume may not be up to date or may be missing. They will be updated in later releases of the disk. The current release of the disk does not contain the raw data reading software described in some documents on the disk. ODMA_0001 The raw and ancillary data directories in ODMA_0001 contain a few data files whose names indicate dates in January 2003. These files contain 2002 data, but have filenames indicating 2003 dates because of the file naming conventions for raw and processed data. (See the INFO.TXT files under the /DATA/RAW_DATA and /DATA/ANCIL directories for details on these file naming conventions.) These files have been placed in the 02_12DEC subdirectories with the December 2002 data. ODMA_0001 A small number of raw and ancillary data files in the and December 2002 subdirectories cover periods crossing ODMA_0002 the 2002-2003 year boundary. These files have been included on both disks (ODMA_0001 and ODMA_0002). ODMA_0002 The time tags in the reduced data files EVN03247_000627.TAB, EVN03248_000000.TAB, and EVN03249_000007.TAB (all located in DATA/REDUCED/03_09SEP) have not been substantially corrected or flagged. The time interval of the raw data file from which these files originated appears to overlap the time intervals of other files; the correct interpretation of the time tags in these three files remains uncertain. In these three files, the corrected time column still exists but contains no (or few) corrections.