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MESSENGER Energetic Particle and Plasma Spectrometer Calibrated 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) calibrated data volume set. There are three
EPPS volumes: one for documentation, one for EDR data, and one for CDR
data. This is the CDR data volume, which contains the actual data.
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
CDR 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.
========================================================================
Known Issues In Data
========================================================================
Some of the EPS Data Types have unusual or unexpected values users
should be aware of:
- The Time of Flight segment of the instrument is no longer operational.
Early observations (2006) were made in a mode such that rates and fluxes
for all ION and Electron channels are all zero in the early files.
Only FAST and SHAPED rates are nonzero.
-The "Delta" values in SCAN mode data are often negative due to
low count rate statistics.
-Certain PHA events are excluded by default in standard instrument team
analysis as they are of indeterminate analytical value:
* Events for which the multi-hit flag is set.
* Events with a negative RAW Energy.
* Events with Maximum (= 4095) RAW Energy.
Users are advised to discard these events as well unless they have
strong reasons to do otherwise.
See the EPPS CDR SIS document for a more detailed explanation of these
issues.
========================================================================
Volume Format
========================================================================
The volume is organized into a hierarchical directory structure. It is
transferred from the MESSENGER SOC to the Planetary Plasma Interactions
Node via the TCP/IP File Transfer Protocol (FTP) and thus 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 CDR SIS
on the DOCUMENT volume.
========================================================================
File Formats
========================================================================
The data files on this volume are provided in ASCII text format
(extension .TAB). 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 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 calibrated volume sets (EPPS_2XXX) includes the
following volumes:
Volume ID. Contents
----------------- -----------------------------------------------------
MESSEPPS_CDR This volume. MESSENGER EPPS calibrated data.
This volume contains EPPS data at Earth, Venus
and Mercury over the interval 2004-216 (3 Aug) to
2009-287 (Oct 14).
MESSEPPS_DOC MESSENGER EPPS documentation for uncalibrated and
calibrated data.
========================================================================
Volume Contents
========================================================================
Directory Structure and Contents for EPPS CDR Data Archive Volume
The following illustration shows the directory structure overview for
the EPPS CDR Data Archive Volume. This volume contains the EPPS CDR 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 CDRs (if needed) will also be delivered according to the
same schedule. Revised CDRs will have an incremented version number in
the PDS label.
Data Volume Directory Structure Overview
<ROOT>
___________________________________|________ ____________
| | | |
<DATA> <GEOMETRY> <INDEX> <LABEL>
|
|______________________________________________________
| | | | | |
| | <EPS_HI_SPECTRA> | <EPS_MED_SPECTRA> |
| <EPS_PHA> | |
| <EPS_HIRES_SPECTRA> <EPS_LORES_SPECTRA>
|_______________________________________
| | |
| <EPS_SUMMARY_SPECTRA> <EPS_SCAN_SPECTRA>
|
|
|
|______________________________________
| | |
| <FIPS_HI_SPECTRA> <FIPS_MED_SPECTRA>
|_________________________________
| | |
| <FIPS_HIRES_PROTON_V> |
| |
<FIPS_SCAN> <FIPS_PHA>
|
|
<2008>
|________________
| | |
<JAN> <FEB> <MAR> ...
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. This includes revised CDRs meant to replace CDRs in a
previous PDS delivery.
<DATA> Directory
This top level directory contains the CDR data products. Directly
underneath the <DATA> directory are subdirectories corresponding to the
nine standard data products (described in the EPPS CDR SIS). The
directories are further subdivided into YEAR and MONTH directories.
Each MONTH directory contains not only the data and label files
associated with the date and data type, but also a *.FMT file that
contains the definition of the CDR files within the directory. The file
is named after the data product in the directory.
<GEOMETRY> Directory
This subdirectory contains information about the files (e.g. SPICE
kernels, etc) needed to describe the observation geometry for the data.
GEOMINFO.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.
<INDEX> Directory
This subdirectory contains the indices for the EPPS CDR 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 CDR 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.
========================================================================
Related PDS Products
========================================================================
========================================================================
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.