PDS_VERSION_ID = PDS3 RECORD_TYPE = STREAM OBJECT = TEXT PUBLICATION_DATE = 2015-03-06 NOTE = "AAREADME.TXT describes this volume." END_OBJECT = TEXT END MESSENGER Energetic Particle and Plasma Spectrometer Calibrated Data MESEPPSCDR_1 Prepared for the Planetary Plasma Interactions Node of the Planetary Data System ======================================================================== Introduction ======================================================================== This volume contains part of the original data from the MESSENGER Energetic Particle and Plasma Spectrometer (EPPS) calibrated 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 Fast Imaging Plasma Spectrometer (FIPS) 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 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 contains PDS documentation describing the instrument and data set. These include: MESS_EPPS_INST.CAT EPPS instrument description MESS_EPPSFIPS_CDR_DS.CAT EPPS FIPS calibrated data set description Additional information on volume organization is given in the CDR SIS in the DOCUMENT directory. ======================================================================== 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 directory. 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 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 FIPS CDR 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 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 MESEPPSCDR_1 ________________________|____________________________________________ | | | | |