PDS_VERSION_ID          = PDS3
RECORD_TYPE             = STREAM
OBJECT                  = TEXT
  PUBLICATION_DATE      = 2012-01-11
  NOTE                  = "AAREADME.TXT describes this volume."
END_OBJECT              = TEXT
END

MESSENGER Energetic Particle and Plasma Spectrometer Uncalibrated Data
Archive

Prepared for the Planetary Plasma Interactions Node of the Planetary
Data System

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

This volume contains data from the MESSENGER Energetic Particle and
Plasma Spectrometer (EPPS) uncalibrated data (EDR) volume set. There 
are three EPPS volumes: one for documentation, one for EDR data, and 
one for CDR data. This is the EDR data volume.

Note that the EPPS is made up of two instrument subsystems, the Fast
Imaging Plasma Spectrometer (FIPS) and the Energetic Particle
Spectrometer (EPS). Thus two data sets are delivered within this data
volume, the FIPS and the EPS. In some cases one file will be relevant
to both data sets, in which case the data set id for both are included
in the one label.

A complete description of the design of this volume is given in the EPPS
EDR software interface specification. An electronic copy of this
document is located in the /DOCUMENT directory on the DOCUMENT volume
(not on this volume).

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

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

The volume is organized into a hierarchical directory structure. It is
transferred from the MESSENGER SOC to the Planetary Plasma Interactions
Node, so the physical characteristics of the final storage media are 
unknown to the SOC.

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

  INSTRUMENT.CAT                EPPS instrument description
  EPPSEPSDATASET.CAT            EPPS EPS uncalibrated data set description
  EPPSFIPSDATASET.CAT           EPPS FIPS uncalibrated data set description
  EPPSEPSDATASET_CDR.CAT        EPPS EPS calibrated data set description
  EPPSFIPSDATASET_CDR.CAT       EPPS FIPS calibrated data set description

Note that these files are NOT on this, the DATA volume, but are instead
included in the DOCUMENT volume.

Additional information on volume organization is given in the EDR SIS
on the DOCUMENT volume.

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

The data files on this volume are provided in ASCII text format 
(extension .TAB) or binary format (extension .DAT). Each data file 
is 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 on the DOCUMENT volume
in ASCII format.

Document files describing the volume and the data are included in the
DOCUMENT volume. Refer to the AAREADME.TXT file on that volume.

Text files and detached label files contain 80-byte fixed-length ASCII
records, with a carriage-return character (ASCII 13) in the 79th byte
and a line-feed character (ASCII 10) in the 80th byte. 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 Set Information
========================================================================

The MESSENGER EPPS uncalibrated volume sets (EPPS_1XXX) includes the
following volumes:

  Volume ID.         Contents
  -----------------  -----------------------------------------------------
  MESSEPPS_EDR       This volume. MESSENGER EPPS uncalibrated data.
                     This volume contains EPPS data at Earth, Venus
                     and Mercury over the interval 2004-216 (3 Aug) to
                     2011-137 (17 May).

  MESSEPPS_DOC       MESSENGER EPPS documentation for uncalibrated and
                     calibrated data.

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

Directory Structure and Contents for EPPS EDR Data Archive Volume

The following illustration shows the directory structure overview for
the EPPS EDR Data Archive Volume. This volume contains the EPPS EDR data
products and any additional files required for the volume to be
compliant with PDS standards. It does not contain supporting
documentation, which is contained on the DOCUMENT volume. 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
(DMAP). 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.

Data Volume Directory Structure Overview

                                 <ROOT>
___________________________________|________ ____________
  |                                         |           |
<DATA>                                   <INDEX>     <LABEL>
   |
   |______________________________________________________
   |    |                    |             |
        |                    |             |
     <EPPS_LONG_STATUS>  <EPPS_STATUS>  <EPS_HI_SPECTRA>  ...                     |
   

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 EPPS 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. 


<DATA> Directory

This top level directory contains the EDR data products. Directly
underneath the <DATA> directory are subdirectories corresponding to the
nine standard data products (described in the EPPS EDR SIS). The
directories are further subdivided into YEAR and MONTH directories.

Each MONTH directory contains the data and label files associated 
with the date and data type.


<INDEX> Directory

This subdirectory contains the indices for the EPPS 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. This includes a description of the structure and
contents of each index table in the subdirectory AND usage notes.

INDEX.TAB - The EDR index file is organized as a table; there is one
entry for each of the data files included in the two EPPS data sets; 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.


<LABEL> Directory

This subdirectory contains the "label fragments" (i.e., the *.FMT files)
for all data products on the volume.  These format files describe the
table and data objects which store the data.


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

Every effort has been made to ensure that the data and documentation are
of the best possible quality. However, mistakes are inevitable. The
Planetary Plasma Interactions (PPI) Node of the PDS will maintain an
online list of ERRATA where errors and updates are documented. Should
any user of this product find an error on this volume, please report the
error to the PPI Node so that the finding can be made public. All
users are encouraged to verify the correctness of the data prior to
submitting any publications or other work based on these data.

There is a file called ERRATA.TXT found at the root level of this volume
which contains a list of known deficiencies or caveats associated with
data on this volume at the time it was published.

If you find an error on this disk, please report the error to the PDS
Operator at the PPI Node of the PDS at the address or numbers listed
under contacts below.

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

For questions concerning these data products and documentation, contact:


          Planetary Plasma Interactions Node
          UNIVERSITY OF CALIFORNIA, LOS ANGELES
          INST. OF GEOPHYSICS AND PLANETARY PHYSICS
          6707 GEOLOGY
          LOS ANGELES, CA 90095-1567 USA

          (310) 206-6073

          WWW Site:  http://pds-ppi.igpp.ucla.edu
          Electronic mail address:  pds_operator@igpp.ucla.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

A list of personnel in the MESSENGER EPPS team that were involved in the
production of this volume is given in /CATALOG/PERSON.CAT on the
DOCUMENT volume.

The PDS, and the Planetary Plasma Interactions Node in particular,
assume no legal liability for errors on this disk. All users are
encouraged to verify the 'correctness' of the data prior to submitting
any publications or other work based on these data. Errors on this
volume should be reported back to the PPI Node of the PDS through the
ERRATA reporting procedures described above.