This volume contains part of the original data from the MESSENGER Energetic
Particle and Plasma Spectrometer (EPPS) derived data volume set.
Note that the EPPS is made up of two instrument subsystems, the Fast
Imaging Plasma Spectrometer (FIPS), and the Energetic Particle
Spectrometer (EPS). This volume includes only the Energetic Particle
Spectrometer (EPS) instrument data. Two data sets were delivered within
the original data volume, the FIPS and the EPS.
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
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 contains PDS
documentation describing the instrument and data set. These include:
MESS_EPPS_INST.CAT EPPS instrument description
MESS_EPPSEPS_DDR_DS.CAT EPPS EPS derived data set description
Additional information on volume organization is given in the DDR SIS
on the DOCUMENT directory.
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.
Directory Structure and Contents for EPPS DDR Data Archive Volume
The following illustration shows the directory structure overview for
the EPPS DDR Data Archive Volume. This volume contains the EPPS EPS DDR data
products 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 (DMAP). Revised DDRs (if needed) will
also be delivered according to the same schedule. Revised DDRs will have
an incremented version number in the PDS label.