X-ray Spectrometer (XRS) Derived Data
MESSENGER Mission to Mercury

This bundle contains the following collections:

data_maps - derived map products
data_footprints - footprints for each XRS CDR observation
document - the XRS CDR/RDR 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 XRS derived product collection consists of a set of footprint polygons for the XRS
field of view during instrument observations and a set of maps showing elemental ratios derived for
the XRS spectra. A description of each product type is given in the table below. Code refers to the
product type abbreviation used in the file name.


Code     Product Type        Description                                             Storage Format

---      Footprint           This product type consists of a set of points in        ASCII         
                             latitude and longitude that correspond to the           Delimited     
                             perimeter field of view of the XRS during integration   Table         
                             time of the calibrated products.                                      

---      Map                 The product type is a series of maps depicting ratios   Image Array   
                             of detected elements and the uncertainties in the       and JPEG2000  
                             ratios. A third set of maps shows the effective map                   
                             resolution.                                                           

XRS Derived map products have the following file names:
xrs_mmm_ee_si_yyyymmdd.xxx
where:
mmm  = Type:
map  = map
unc  = uncertainty
res  = resolution
ee   = 2-character element identifier
al   = aluminum
ca   = calcium
fe   = iron
mg   = magnesium
s_   = sulfur
si   = element consequent in the ratio = silicon
yyyy = 4-digit year corresponding to the last CDR sample included in the map
mm   = 2-digit month (01-12) corresponding to the last CDR sample included in the map
dd   = 2-digit day of month (01-31) corresponding to the last CDR sample included in the map
xxx  = file type (jp2 or img)

XRS Derived footprint products have the following file names:
xrs_fp_p_met.csv
where:
p   = Spacecraft clock time partition (1 or 2)
met = Spacecraft clock time in seonds

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.