Gamma Ray Spectrometer (GRS) Calibrated and Derived Data MESSENGER Mission to Mercury This bundle contains the following collections: data_cdr - calibrated GRS data products data_maps - derived GRS map data products document - the GRS CDR-RDR-DAP Software Interface Specification and other relevant documents miscellaneous - the PDS3 index table for this archive This PDS4 bundle has been migrated from a PDS3 data volume. For details, see the document geo_notes_and_errata.pdf in the document collection. Each document and data product in this bundle is described by a PDS4 label in a separate file with the same name but with the extension XML. PDS4 labels are XML (eXtended Markup Language) files that conform to the PDS4 Information Model XML schema at https://pds.nasa.gov/pds4/schema/released/. They are best viewed in an XML-aware text editor, and may be used by software that can manipulate XML documents. The MESSENGER GRS calibrated product collection consists of GRS data that have been calibrated for instrument and geometrical effects. There are eight product types in this collection that include spectra in addition to engineering and shield count rate data. Spectral products contain spacecraft navigation and attitude data derived from SPICE files, as well as selected relevant engineering data. A single product typically contains data collected over one Earth day. A description of each product type is given in the table below. Code refers to the product type abbreviation used in the file name, where relevant. Code Product Type Description Storage Format CAC Anti-Coincidence This product type contains Anti-Coincident (AC) Binary Table Spectra spectra collected from the high-purity germanium (HPGe) detector plus spatial and temporal information and relevant engineering, counter, and pulser data from the time the spectra was taken. Spectra have been corrected to a common energy scale. CRA Ge Raw Spectra This product type contains spectra collected from the Binary Table high-purity Germanium (HPGe) detector plus spatial and temporal information and relevant engineering, counter and pulser data from the time the spectra was taken. Spectra have been corrected to a common energy scale. CS2 Shield Spectra 2 This product type contains spectra observed in the Binary Table GRS shield and associated timing, spatial, and engineering data. These products were generated after September 17, 2010 due to a flight software update. CS3 Shield Spectra 3 This product type contains spectra observed in the ASCII Table GRS shield. These products have timing, spatial and engineering readings taken at the mid-point of the spectral collection period associated with it. These products were generated after March 17, 2013 due to a flight software update. CSC Shield Count Rate The GRS shield count rate product contains time ASCII Table series measurements of the total count rate measured by the GRS anti-coincidence shield, and are due to incident particles (primarily electrons, but also gamma rays, protons, and neutrons). These products were generated after March 17, 2013 due to a February 25, 2013 flight software upload. CSH Shield Spectra This product type contains spectra observed in the Binary Table GRS shield with associated timing, spatial, and engineering data. These products were generated prior to September 17, 2010. ENG Engineering The engineering products contain selected data from Binary Table the GRS raw status files converted to calibrated physical units. RSS Spectral Sum This product type contains spectra summed from the Ge Binary Table Raw and the Anti-Coincident Spectra acquired with limited geometric conditions plus spatial and temporal information and relevant data from the time the spectra were taken. GRS Calibrated products have the following file names: grs_zzzyyyydddwww.xxx where: zzz = Product Type (Code) yyyy = 4-digit year corresponding to the start-time of the first record in the GRS data file ddd = 3-digit day of the year corresponding to the start time of the first record in the product www = reserved 3-character string to use during the course of the mission as necessary to identify “special” data products; nominal data products will be identified with “ZZZ” xxx = File extension: dat = Binary table file tab = ASCII table file GRS Engineering Calibrated products have the following file names: grs_zzzyyyydddwww.dat where: zzz = Product Type (Code) exx = Engineering data where xx is the "CDR Index" listed in Appendix 8.4 of the SIS. yyyy = 4-digit year corresponding to the start-time of the first record in the GRS data file ddd = 3-digit day of the year corresponding to the start time of the first record in the product www = reserved 3-character string to use during the course of the mission as necessary to identify “special” data products; nominal data products will be identified with “ZZZ” The MESSENGER GRS derived product collection has a series of maps derived from the GRS instrument for the northern hemisphere of Mercury. These were created from calibrated gamma ray spectra, represent spatially resolved measurements, and have been highly processed to remove variability originating from detector altitude and viewing geometry. The measurements were also corrected for dead time. Code refers to the product type abbreviation used in the file name. Code Product Type Description Storage Format DAP Map The maps are either gamma ray count rates or derived Image Array elemental abundances. and JPEG2000 GRS DAP products have the following file names: grs_zzz_y_www_uuu.xxx where: zzz = Product Type (Code) y = Element name in periodic table: k = Potassium si = Silicon o = Oxygen www = Map type: abd = abundance gcr = gamma-ray count rate uuu = Map contents: map = data error = error xxx = File extension: jp2 = JPEG-2000 img = Image File This bundle was created and archived by the Geosciences Node of the Planetary Data System. Questions about this bundle may be directed to geosci@wunder.wustl.edu.