PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM INSTRUMENT_HOST_NAME = "2001 MARS ODYSSEY" INSTRUMENT_NAME = "GAMMA RAY SPECTROMETER" TARGET_NAME = MARS OBJECT = TEXT PUBLICATION_DATE = 2009-04-01 NOTE = "Notes and errata for the Odyssey GRS DND archive" END_OBJECT = TEXT END April 1, 2009. Release 27. -------------------------- This delivery covers data acquired between July 1 and September 30, 2008; however, the GRS instrument suite was turned off during this time. It was turned on again on November 6, 2008. Only engineering and message EDR data are available for this release. No derived data products were generated. January 1, 2009. Release 26. ---------------------------- No data are available for June 5, 2008, due to a GRS safe mode event. No neutron spectrometer data are available for June 8-30, 2008, and no gamma ray spectrometer or HEND data are available for June 9-30, 2008, due to a GRS instrument reset event. October 1, 2008. Release 25. ---------------------------- No errors or changes are reported with this release. July 1, 2008. Release 24. ------------------------- No errors or changes are reported with this release. April 4, 2008. Release 23. -------------------------- There are no EDR, DHD, or DND products for September 15-20 due to a GRS anneal and safe mode. DND data for September 27-30 are not archived due to instrument pointing issues. January 8, 2008. Release 22 update. ----------------------------------- DND products with an incorrect value of zero for the orbit number, as reported on 1/1/08, have been corrected. January 1, 2008. Release 22. ---------------------------- DND data records between the times 2007-05-12T18:16:05 and 2007-05-14T21:59:34 have an incorrect value of zero for the orbit number. These products will be corrected. October 1, 2007. Release 21. ---------------------------- No errors or changes are reported for this release. July 1, 2007. Release 20. ------------------------- Data gaps occur in the DND data on these dates: Oct. 1-3, 9, and 19-26, Nov. 4, 7, and 15, and Dec. 6-15, 2006, due to the GCR counter being out of range. Two records in the DND file for 11-25-2006 have time values out of sequence. Shown below are the times for the questionable records and the records before and after. Case 1 2006-11-25T22:06:35.122Z 2006-11-25T22:06:54.884Z 2006-11-25T22:06:28.864Z Case 2 2006-11-25T22:48:11.419Z 2006-11-25T22:47:25.638Z 2006-11-25T22:47:45.399Z April 24, 2007. Release 19. --------------------------- No errors or changes are reported for this release. January 1, 2007. Release 18. ---------------------------- In this release, no DND data are archived for June 19 through June 22, 2006. The galactic cosmic-ray flux was too high. October 1, 2006. Release 17. ---------------------------- There are no DND products from March 23 and 24, 2006, due to the Odyssey spacecraft being in safe mode. The file dataset.cat in the catalog directory has been revised. The file references.cat in the document directory has been revised. July 1, 2006. Release 16. ------------------------- There are no DND products from October 1 through October 12, 2005, due to the low voltage problem first reported in Release 15. The file dataset.cat in the catalog directory has been revised. The files bad_data_timeline.txt and references.txt in the document directory have been revised. April 3, 2006. Release 15. -------------------------- Neutron spectrometer data collected in between July 13 and October 4, 2005 are suspect due to low voltage on the high voltage power supply. As a consequence DND and AND products were not produced between these dates. A command was sent to the instrument on October 4, 2005 to change high voltage power supplies. The result of this command was an increase in the voltage that allows for more accurate ground data processing of the NS data. January 1, 2006. Release 14. ---------------------------- Between April 3 and April 6, 2005, the Odyssey spacecraft was in safe mode, so GRS data is missing for those dates. Solar events on May 16-17 and June 17-18, 2005, were also responsible for some data gaps. See the file bad_data_timeline.txt in the document directory for details of data gaps. The file dataset.cat in the catalog directory has been updated with additions to the list of data gaps. The files bad_data_timeline.txt and time_conversion_tables.pdf in the document directory have been updated, and the file references.txt has been added. October 1, 2005. Release 13. ---------------------------- In this release, no DND data are archived for January 1, January 7, and January 19 through February 2. The galactic cosmic-ray flux was on average above the threshold of 7500 counts on January 1 and January 7. There are no DND products from January 19 through February 2 due to two solar particle events. This release includes a new file, bad_data_timeline.txt, in the document directory. This file lists the time ranges during which the bad data flag was set manually for various reasons, including solar particle events. The bad data flag is found in the Neutron Spectrometer EDR product from which the DND product is derived. July 1, 2005. Release 12. ------------------------- This release includes several data gaps, periods of time during which no Neutron Spectrometer data were collected. The gaps were due to a major solar particle event centered around November 15, 2004, and surrounding periods of solar activity higher than the Neutron Spectrometer threshhold. April 25, 2005. --------------- The file mission.cat in the catalog directory has been updated to include a discussion of Odyssey Extended Mission 1. April 1, 2005. Release 11. -------------------------- No errors are reported for this release. January 1, 2005. Release 10. ---------------------------- 1. The galactic cosmic ray threshold coefficient was increased by 7% for the new DND and AND products in this release, due to rising background flux. 2. DND products covering Feb. 5 through Feb. 16, 2004, were included in this delivery because some of them were inadvertently omitted from the previous delivery in which they belonged. 3. This file in the catalog directory has been revised. dataset.cat October 1, 2004. Release 9. --------------------------- 1. DND products covering the dates Feb. 6, 2004 through Feb. 12, 2004 were inadvertently omitted from this delivery. They will be included in the next Odyssey release, December 1. July 1, 2004. Release 8. ------------------------ 1. In this release the content and structure of the DND product have been revised, and DND data from the beginning of the mission through Dec. 31, 2003, have been released. The file names of DND products now follow the scheme DND_yyyymmdd.DAT rather than DERIV_NEUTRON_DATA_yyyymmdd.DAT as in previous releases. 2. These files in the catalog directory have been revised. dataset.cat ref.cat 3. In the document directory the file grs-idr-sis.pdf has been revised, and a new file, grs_ns_processing.pdf, has been added. 4. In the label directory the file deriv_neutron_data_cols.fmt has been revised. 5. All files in the software directory have been revised. April 1, 2004. Release 7. ------------------------- 1. No DND data were included in this release. January 7, 2004. Release 6. --------------------------- 1. These files in the catalog directory have been revised. dataset.cat ref.cat October 1, 2003. Release 5. --------------------------- 1. This file in the document directory is new. time_conversion_tables.pdf 2. This file in the catalog directory has been revised. dataset.cat July 31, 2003. Release 4. ------------------------ 1. This is the first time Derived Neutron Data (DND) products have been included in an Odyssey GRS data release. There are no errata to report for this release.