PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM
OBJECT                  = TEXT
  PUBLICATION_DATE      = 2015-10-09
  NOTE                  = "AAREADME.TXT describes this volume."
END_OBJECT              = TEXT
END

MESSENGER Mercury Atmospheric and Surface Composition Spectrometer (MASCS)
Ultraviolet and Visible Spectrometer (UVVS) and Visible And Infrared
Spectrograph (VIRS) Uncalibrated Data Archive

========================================================================
Introduction
========================================================================

This volume contains uncalibrated (EDR) data from both detectors on the
Mercury Atmospheric and Surface Composition Spectrometer (MASCS) instrument,
the Ultraviolet and Visible Spectrometer (UVVS) and the Visible And Infrared
Spectrograph (VIRS).

These two data sets are fully described by Software Interface Specification
documents in the DOCUMENT directory of this volume, in the files UVVSEDRSIS.*
and VIRSEDRSIS.*.

This volume is intended for the use of scientists and students in the study 
of the geography and geochemistry of the planet Mercury. The data may be 
used for research and publication.

========================================================================
Volume Format
========================================================================

All science data are located under the DATA directory. The INDEX directory 
contains a listing of all of the data products included on the volume. The 
CATALOG directory contains PDS documentation describing the mission, 
spacecraft, instrument, and data sets. These include:

  MISSION.CAT              MESSENGER mission description
  INSTHOST.CAT             MESSENGER spacecraft description
  INST.CAT                 MASCS instrument description
  UVVS_DS.CAT              MASCS/UVVS uncalibrated data set description
  VIRS_DS.CAT              MASCS/VIRS uncalibrated data set description
  REF.CAT                  MESSENGER mission reference citations,
                           including MASCS/VIRS and MASCS/UVVS references.
  PERSON.CAT               MASCS personnel contact information.


Additional information on volume organization is given in the EDR SIS
documents mentioned above and in the section 'Volume Contents' below.

========================================================================
File Formats
========================================================================

The data files on this volume are provided in flat IEEE binary format
(extension .DAT). Each data file is also accompanied by a detached PDS label 
file (extension .LBL), an ASCII file containing information describing the 
data file and data record format.

Catalog files (extension .CAT) are provided in ASCII format.

Document files describing the volume and the data are given in ASCII and PDF  
formats.

Text files and detached label files contain ASCII records terminated with
a carriage-return character (ASCII 13) and a line-feed character (ASCII 10).
This format allows the files to be read by MacOS, DOS, UNIX and VMS operating
systems. Note that while both label and catalog files are ASCII, some 
operating systems will not recognize the .LBL and .CAT extensions as ASCII 
types. It may be necessary to either remap these extensions as ASCII in the 
system or text browser, or else to open the files from within the text 
browser.  

========================================================================
Volume Contents
========================================================================

Directory Structure and Contents for MASCS EDR Data Archive Volume

The following illustration shows the directory structure overview for the
MASCS EDR archive volume, which bears the PDS-assigned volume ID 
MESSMAS_1001. This volume contains the MASCS VIRS and UVVS EDR data 
products, supporting documentation, and any additional files required for 
the volume to be compliant with PDS standards. The content of the volume is 
expected to be updated with periodic releases according to the schedule 
found in the MESSENGER Data Management and Archiving Plan. Revised EDRs (if 
needed) will also be delivered according to the same schedule. Revised EDRs 
will have an incremented version number in the PDS label.

Directory Structure Overview

                                <ROOT>
__________________________________|__________________________________
    |          |         |        |         |          |        |    
<GEOMETRY>  <INDEX>  <CATALOG>  <DATA>  <DOCUMENT>  <LABEL>  <EXTRAS>
                                  |
                                  |
                                <mmm>
                                  |
                                  |                                  
                           <MASCSYYYYMMDD> 
                                  |
                                  |
                                  |
                             _____|_____________
                             |         |      |         
                             |         |      |
                           <UVVS>    <VIRS>  <HK>

Directory Contents:

<ROOT> Directory

This is the top-level directory of the data volume. The following are files 
contained in the root directory.

AAREADME.TXT: (This file) General information file. Provides users with 
information about the MESSENGER MASCS data products. Directs user to other 
documents on the volume containing more detailed information.

VOLDESC.CAT: PDS file containing the VOLUME object. This gives a high level 
description of the contents of the volume. Information includes: production 
date, producer name and institution, volume ID, etc.

ERRATA.TXT: Text file for identifying and describing errors and/or anomalies 
found in the current volume, and possibly previous volumes of a set. Any 
known errors for the associated volume will be documented in this file. This 
includes revised EDRs meant to replace EDRs in a previous PDS delivery.

<DOCUMENT> Directory

This subdirectory contains the documentation that will be needed in order to 
understand and analyze the EDR data products. Files will be stored in PDF     
and ASCII format.               

DOCINFO.TXT: Identifies and describes the function of each file in the
DOCUMENT directory.

UVVSEDRSIS.TXT:  The MASCS/UVVS EDR SIS: "Experiment Data Record Software 
Interface Specification for the MESSENGER Mercury Atmospheric and Surface 
Composition Spectrometer/Ultraviolet and Visible Spectrometer (MASCS/UVVS) 
SIE-06-044 D" in ASCII text format. Only the text is provided; for 
illustrations, tables, etc. one of the other formats should be consulted.     
                                                                              
UVVSEDRSIS.PDF:  The MASCS/UVVS EDR SIS: "Experiment Data Record Software 
Interface Specification for the MESSENGER Mercury Atmospheric and Surface 
Composition Spectrometer/Ultraviolet and Visible Spectrometer (MASCS/UVVS) 
SIE-06-044 D" in Adobe Acrobat format.  Note that, in contrast to the .TXT 
version, the illustrations, tables, etc. will display appropriately.

UVVSEDRSIS.LBL: A detached PDS label that describes the text and PDF files.

VIRSEDRSIS.TXT:  The MASCS/VIRS EDR SIS: "Experiment Data Record Software 
Interface Specification for the MESSENGER Mercury Atmospheric and Surface 
Composition Spectrometer/Visible And Infrared Spectrograph (MASCS/VIRS) 
SIE-06-045 D" in ASCII text format. Only the text is provided; for 
illustrations, tables, etc. one of the other formats should be consulted.     
                                                                              
VIRSEDRSIS.PDF:  The MASCS/VIRS EDR SIS: "Experiment Data Record Software 
Interface Specification for the MESSENGER Mercury Atmospheric and Surface 
Composition Spectrometer/Visible And Infrared Spectrograph (MASCS/VIRS) 
SIE-06-045 D" in Adobe Acrobat format.  Note that, in contrast to the .TXT 
version, the illustrations, tables, etc. will display appropriately.

VIRSEDRSIS.LBL: A detached PDS label that describes the text and PDF files.

<CATALOG> Directory

This subdirectory contains the catalog object files for the entire volume. 
The following files are included in the catalog subdirectory.

CATINFO.TXT: Identifies and describes of function of each file in the 
catalog directory.

UVVS_DS.CAT, VIRS_DS.CAT: Describes the general content of the datasets and 
includes information about the duration of the mission and the person or 
group responsible for producing the data.

INST.CAT: Describes physical attributes of the MASCS instrument and provides 
relevant references to published literature.

INSTHOST.CAT: Describes the MESSENGER spacecraft.

MISSION.CAT: Describes the scientific goals and objectives of the MESSENGER 
program.

REF.CAT: Contains the complete citations of references mentioned in the 
above catalog files, along with citations of additional documents that may 
be useful to the person using the MASCS EDR data.

PERSON.CAT: Lists and provides contact information for the people involved 
with the MASCS instrument on the MESSENGER mission.

<INDEX> Directory

This subdirectory contains the indices for the MASCS EDR data products. The 
following files are contained in the index subdirectory.

INDXINFO.TXT: Identifies and describes the function of each file in the 
index subdirectory.

INDEX.TAB: The EDR index file is organized as a table. There is one entry 
for each of the data files included in the MASCS data set. The columns 
contain parameters that describe the data as well as instrument and 
spacecraft parameters.

INDEX.LBL: Detached PDS label for INDEX.TAB.

MD5.TAB: Provides the MD5 checksum (message digest) for each file in the 
archive, with the exception of the MD5.TAB file itself.

MD5.LBL: Detached PDS label for MD5.TAB.

<GEOMETRY> Directory

This subdirectory contains information about the files (e.g. SPICE kernels, 
etc) needed to determine the observation geometry for the data.

GEOMETRY.TXT: Identifies and describes the SPICE kernels that a user must 
have in order to determine observation geometry for the data. The SPICE 
kernel files are archived with the PDS NAIF node.

<LABEL> Directory

This subdirectory contains format files that are referenced in the PDS labels
for UVVS, VIRS and housekeeping data files. These format files define the 
structure and contents of the binary data tables. Software that interprets PDS
labels will automatically include these files to determine how to read the 
data.

LABINFO.TXT: Describes this directory.

UVVS.FMT: Format of MASCS UVVS EDR data products.

VIRS.FMT: Format of MASCS VIRS EDR data products.

MASCS_HK.FMT: Format of MASCS housekeeping data products.

<EXTRAS> Directory 

This subdirectory contains ancillary material that may be useful but is not 
required for the understanding of the archive.

VIRS_MISSING_PACKETS_R6.TXT: This file describes the investigation and 
resolution of the missing packet error described in the "Data Coverage and 
Quality" section of VIRS_DS.CAT (Note 6). Included is a list of the EDRs 
(and thus also CDRs) missing packets for PDS release 6. 

VIRS_VIS_EDR_MISSING_PACKET_ANALYSIS_R6.XLS: This is a companion spreadsheet 
to the file above. It shows a detailed breakdown of the EDRs and exactly 
which packets are missing.

VIRS_VIS_MISSING_PACKETS_R*.TXT: These files list the incomplete VIRS VIS 
EDRs/CDRs for PDS releases, where '*' is the release #. The errors are 
described in the "Data Coverage and Quality" section of VIRS_DS.CAT.  

VIRS_NIR_MISSING_PACKETS_R*.TXT: These files list the incomplete VIRS NIR 
EDRs/CDRs for PDS releases, where '*' is the release #. The errors are 
described in the "Data Coverage and Quality" section of VIRS_DS.CAT.

MASTER_CRUISE_TABLE.XLS: This is an extended instrument operation table used 
during cruise and flyby operations of MASCS, showing details of VIRS and 
UVVS observations, times, and other information useful for quick reference. 
In orbit, the mission planning software SCIBOX takes over the function of 
this table. This file can be viewed using Microsoft Excel.  

<DATA> Data Directory

This is the top level directory for the EDR data products. Directly 
underneath the <DATA> directory are the <mmm> directories. The "mmm" 
characters define the mission phase, where:

         EAC = Earth cruise to Earth flyby
         EAF = Earth flyby
         VC1 = cruise, post Earth flyby to pre-Venus 1 flyby
         VF1 = Venus 1 flyby
         VC2 = cruise, post Venus 1 to pre-Venus 2 flyby
         VF2 = Venus 2 flyby 
         MC1 = cruise, post Venus 2 to pre-Mercury 1 flyby
         MF1 = Mercury 1 flyby
         MC2 = cruise, post Mercury 1 to pre-Mercury 2 flyby
         MF2 = Mercury 2 flyby
         MC3 = cruise, post Mercury 2 to pre-Mercury 3 flyby
         MF3 = Mercury 3 flyby
         MC4 = cruise, post Mercury 3 to pre-orbit insertion
         ORB = orbit insertion until end of nominal orbit mission
         OB2 = second year of orbital operations
         OB3 = third year of orbital operations
         OB4 = fourth year of orbital operations
         OB5 = fifth year of orbital operations

Below the mission phase directories are the <MASCSYYYYMMDD> directories. The 
"YYYYMMDD" characters define the four digit year, 2 digit month, and 2 digit 
day which is common to all the MET times for the EDRs stored in that 
directory. Each of these directories is further subdivided into as many as 
three subdirectories, one for each component of the MASCS instrument, and an 
additional subdirectory for the housekeeping EDR:

         <UVVS> - UVVS Subdirectory.
         <VIRS> - VIRS Subdirectory.
           <HK> - Housekeeping EDR subdirectory.

Each of these directories contains the EDR data files themselves (*.DAT) 
and, for each EDR data file, a detached label file (*.LBL). Subdirectories
only exist if that particular type of data exists for that day. If there are 
no data of a particular type for a particular day, no subdirectory is 
included for that type.

========================================================================
Errata
========================================================================

Every effort has been made to ensure that the data and documentation are of 
the best possible quality. However, all users are encouraged to verify the 
correctness of the data prior to submitting any publications or other work 
based on these data.

The file ERRATA.TXT at the root level of this volume contains a list of       
known deficiencies or caveats associated with data on this volume at the      
time it was published, if any. It also lists any revisions that have been    
made to the data set as a whole or to individual products.

If you find an error on this volume, please report the error to the PDS, 
using the contact information below. 

========================================================================
Contacts
========================================================================

For questions concerning VIRS data products and documentation, contact:

          PDS Geosciences Node
          Washington University
          Dept. of Earth and Planetary Sciences
          1 Brookings Drive
          St. Louis, MO 63130
          314-935-5493

          WWW Site:  http://pds-geosciences.wustl.edu
          Electronic mail address:  geosci@wunder.wustl.edu

For questions concerning UVVS data products and documentation, contact:

          PDS Atmospheres Node                                   
          Astronomy Department                                                
          New Mexico State University                                         
          P.O. Box 30001, Dept 4500                                           
          Las Cruces, NM 88003                                                
                                                                              
          WWW Site:  http://pds-atmospheres.nmsu.edu                          
          Electronic mail address:  rbeebe@nmsu.edu                           
                                                                              
For questions regarding PDS Standards or other archive volumes available      
from the PDS, please contact PDS Operator at the PDS Central Node (at         
JPL):                                                                         
                                                                              
                                                                              
    Internet            pds_operator@jpl.nasa.gov                             
    Telephone           (818) 354-4321                                        
    U.S. Mail           Planetary Data System, PDS Operator                   
                        Jet Propulsion Laboratory                             
                        Mail Stop 202-101                                     
                        4800 Oak Grove Dr.                                    
                        Pasadena, CA 91109-8099