DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-CDR-V1.0" DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED FIPS V1.0" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_OBJECT_TYPE = TABLE START_TIME = 2004-229T19:54:49 STOP_TIME = 2015-120T15:08:18 DATA_SET_RELEASE_DATE = 2016-05-06 ARCHIVE_STATUS = "ARCHIVED" PRODUCER_FULL_NAME = "JIM RAINES" DETAILED_CATALOG_FLAG = "N" CITATION_DESC = "{Jim Raines}, MESSENGER E/V/H/SW EPPS CALIBRATED FIPS CDR V1.0, MESS-E/V/H/SW-EPPS-3-FIPS-CDR-V1.0, NASA Planetary Data System, 2009." DATA_SET_TERSE_DESC = "The MESSENGER EPPS calibrated observations consist of energetic particle and plasma data collected by the EPPS instrument during fly-by and orbital operations of Mercury. Also included are cruise observations for calibration purposes." ABSTRACT_DESC = " Abstract ======== This data set consists of the MESSENGER Energetic Particle and Plasma Spectrometer (EPPS) calibrated observations, also known as CDRs. The system encompasses 2 instrument subsystems - the Energetic Particle Spectrometer (EPS) and the Fast Imaging Plasma Spectrometer (FIPS). This data set contains FIPS instrument data. FIPS covers the energy/charge range of < 50 eV/q to 20 keV/q. There are five FIPS CDR data products." DATA_SET_DESC = " Data Set Overview ================= The data set consists of calibrated observations, also known as CDRs. For all the CDR products there is a detached PDS label file that describes the contents of one data file. Each label file will have the same base name as the data file it is describing, with the extension .LBL to denote a label file. The label file defines the start time and end of the observation, product creation time, and the structure of the binary (or ASCII) tables. Each data product is identified within the PDS label by a STANDARD_DATA_PRODUCT_ID value, shown in parentheses in the table below. The FIPS portion of the data archive currently consists of five CDR data products. The following table shows the different FIPS data products and their files. Following is a description of each of the current FIPS CDRs. A more complete description of each may be found in the EPPS CDR SIS document, located in the DOCUMENT directory of the document volume. Additionally, ancillary calibration products, FIPA_*.TAB, are included as part of this data set, but reside separately in the Documentation Volume (MESSEPPS_DOC) in the CALIBRATION directory. Current FIPS Data Products: FIPS High Priority Spectra (FIPS_HI_SPECTRA) Spectra Data file contains flux spectra and proton velocity distribution. FIPS Medium Priority Spectra (FIPS_MED_SPECTRA) Spectra Data file contains flux spectra and proton velocity distribution. FIPS Pulse Height (FIPS_PULSE_HEIGHT) Contains FIPS Pulse Height Analysis data. FIPS SCAN (FIPS_SCAN) Contains flux spectra. Available only after the FSW6 upload. FIPS High Resolution Proton Velocity Distribution (FIPS_HIRES_PROTON_V) Contains a 32 x 32 high resolution proton velocity distribution, integrated over a 10 scan sequence. Available only after the FSW6 upload. Instrument Overview =================== The FIPS sensor consists of an electrostatic analyzer (ESA), located at the entrance to the sensor, a post-acceleration chamber between the output of the ESA and the carbon foil, and a time-of-flight telescope. The ESA at the entrance to the FIPS acts as a wide-angle lens for ions. It only allows ions with a specific energy/charge band to enter through its output plane. See the EPPSINST.CAT file for more information and [ANDREWSETAL2007] for full details. Calibration Overview ==================== This data set is calibrated. Spectral rates have been converted from raw counts to counts/sec and, where possible, to fluxes. Pulse height measurements are reported in calibrated keVs. See the calibration implementation document for details. Parameters ========== The energy per charge (E/q) tables are programmable as described in the CDR SIS document and EDR to CDR calibration document. Data ==== The FIPS CDR data set products are described as follows (the STANDARD_ DATA_PRODUCT_ID value is given in parentheses). The notes provided in brackets give the current status of the data product in version 2 of the data set. The High Priority FIPS Spectra CDR (FIPS_HI_SPECTRA_CDR) contains flux spectra collected in scan 10 of the 10 scan sequence and proton velocity distribution (8x8) for scan 10 of the 10 scan sequence. The Medium Priority FIPS Spectra CDR (FIPS_MED_SPECTRA_CDR) contains flux spectra collected in scans 1-9 of the 10 scan sequence and proton velocity distribution (8x8) for scans 1-9 of the 10 scan sequence. The FIPS Pulse Height CDR (FIPS_PULSE_HEIGHT_CDR) contains FIPS Pulse Height Analysis events collected in scans 1-10 of the 10 scan sequence. The FIPS Scan CDR (FIPS_SCAN_CDR) contains Flux spectra collected in scans 1-9 of the 10 scan sequence. The FIPS High Resolution Proton Velocity Distribution (FIPS_HIRES_PROTON_V_CDR) contains high resolution proton velocity distribution (32x32) for scans 1-10 of the 10 scan sequence." CONFIDENCE_LEVEL_NOTE = " Confidence Level Overview ========================= The EPPS CDR data are the processed data set released for the EPPS. Data presented here are an accurate representation of the EPPS data as received from the spacecraft and have been processed from instrument unit to physical unit. Review ====== The EPPS CDR was reviewed internally by the EPPS team prior to release to the PDS. PDS also performed an external review of the EPPS CDR. Data Coverage and Quality ========================= Data reported are the processed data received from the spacecraft during the following mission phases: Launch, Earth Cruise, Earth Flyby, Venus 1 Cruise, Venus 1 Flyby, Venus 2 Cruise, Venus 2 Flyby, Mercury 1 Cruise, Mercury 1 Flyby, Mercury 2 Cruise, Mercury 2 Flyby, Mercury 3 Cruise, Mercury 3 Flyby, Mercury 4 Cruise, Mercury Orbit, Mercury Orbit Year 2, Mercury Orbit Year 3, Mercury Orbit Year 4, and Mercury Orbit Year 5. These mission phases are defined as: Start time End time Phase Name Date (DOY) Date (DOY) ----------------- ---------------- ---------------- Launch 03 Aug 2004 (216) 12 Sep 2004 (256) Earth Cruise 13 Sep 2004 (257) 18 Jul 2005 (199) Earth Flyby 19 Jul 2005 (200) 16 Aug 2005 (228) Venus 1 Cruise 17 Aug 2005 (229) 09 Oct 2006 (282) Venus 1 Flyby 10 Oct 2006 (283) 07 Nov 2006 (311) Venus 2 Cruise 08 Nov 2006 (312) 22 May 2007 (142) Venus 2 Flyby 23 May 2007 (143) 20 Jun 2007 (171) Mercury 1 Cruise 21 Jun 2007 (172) 30 Dec 2007 (364) Mercury 1 Flyby 31 Dec 2007 (365) 28 Jan 2008 ( 28) Mercury 2 Cruise 29 Jan 2008 (029) 21 Sep 2008 (265) Mercury 2 Flyby 22 Sep 2008 (266) 20 Oct 2008 (294) Mercury 3 Cruise 21 Oct 2008 (295) 15 Sep 2009 (258) Mercury 3 Flyby 16 Sep 2009 (259) 14 Oct 2009 (287) Mercury 4 Cruise 15 Oct 2009 (288) 03 Mar 2011 (062) Mercury Orbit 04 Mar 2011 (063) 17 Mar 2012 (077) Mercury Orbit Year 2 18 Mar 2012 (078) 17 Mar 2013 (076) Mercury Orbit Year 3 18 Mar 2013 (077) 17 Mar 2014 (076) Mercury Orbit Year 4 18 Mar 2014 (077) 17 Mar 2015 (076) Mercury Orbit Year 5 18 Mar 2015 (077) 30 Apr 2015 (120) No EPPS data were collected during Venus 1 Flyby phases. The EPPS was on for brief periods during the other six mission phases prior to Venus 2 Cruise. During these planned operational periods, the EPS sensor on the EPPS did not have high voltage enable, hence no Time-of-flight data and only spectra data were collected. The EPS was turned on for the Venus 2 Flyby and to be remained on throughout the remainder of the mission phases. EPPS data were collected during all Mercury Flybys. EPS High Ion Sector 1 and 5 have malfunction detectors and do not produce any data product. The lowest energy channel (32 to 55 keV) on the High Ion Sector 3 and 5 have periodic high count that are due to flight software interaction with the instrument and should not be used. User of EPS data should consult with the instrument team at JHU/APL to verify the quality of specific data in certain time interval prior to publication. On 18 Aug 2008 (231), a new Flight Software (FSW) was uploaded to EPPS. This new FSW (v6) enhances the energy resolution for EPS and adds a high-resolution proton distribution data packet on FIPS. Description of these new data products are included in the FMT file. In addition, the new FSW v6 fixed the data spikes in the EPS data (as mentioned in the previous paragraph). On 18 Aug 2009 (230), another new FSW was uploaded to EPPS. This new FSW (v7) only affects the FIPS data. In the nominal flight configuration, the FIPS sensor on the EPPS field-of-view will not measure the solar wind. Periodically, the spacecraft was rotated such that the FIPS field-of-view can detect the nominal radial flowing solar wind. These periods typically lasted less than 3 hours and are identified as: Start time End time Phase Name Date (DOY) Date (DOY) ----------------- ---------------- ---------------- Earth Cruise 05 Apr 2005 (105) 05 Apr 2005 (105) Earth Flyby 02 Aug 2005 (214) 02 Aug 2005 (214) 07 Aug 2005 (219) 07 Aug 2005 (219) Venus 1 Cruise 27 Feb 2006 (058) 27 Feb 2006 (058) 06 Sep 2006 (249) 10 Sep 2006 (253) Venus 1 Flyby No Data Venus 2 Cruise 01 Mar 2006 (060) 01 Mar 2006 (060) A dark count signature was discovered in the FIPS PHA data. These counts appear in a time-of-flight -- E/q histogram of PHA data as straight tracks in E/q, centered at about 8 different time-of-flights. These dark counts significantly complicate the analysis of FIPS PHA data, though not significantly for low mass ions (H+, He+ and He2+). All data since launch is affected. This situation has been well characterized by the FIPS team and models/algorithms for removing these counts have been developed. These algorithms are currently being refined and will be published and included in PDS documentation soon. A small bug was found in FSW v7 which causes only the high order 4 bits of the wedge, strip and zigzag values are transmitted in the data. This has the effect of reducing the position resolution for heavy ions in the FSW v7 data. A software patch which eliminates this bug was uploaded to the spacecraft at 19:15Z on 16 Dec 2009 (350). Most of the Mercury 4 cruise phase was spent running flight tests in support of the dark counts investigation. As such, this data is not useful for scientific studies. There are two periods which are exceptions, but the instrument was run in somewhat different voltage configurations during those periods, so care should be taken during data analysis: Start time End time MCPHV PAHV Phase Name Date (DOY) Date (DOY) (V) (kV) ----------------- ---------------- ---------------- ----- ----- Mercury 4 cruise 09 Jul 2010 (190) 29 Jul 2010 (210) -2500 -10.5 Mercury 4 cruise 01 Nov 2010 (305) 31 Nov 2010 (335) -2520 -9.5 In orbit (Mercury Orbit phase), FIPS is regularly taken out of nominal configuration for various spacecraft operations, such as commanded momentum dumps and eclipses, typically prevent possible high voltage discharge within FIPS or for power considerations. On occasion, the EPPS flight software autonomously takes FIPS out of nominal configuration in response to an anomaly. There intervals are marked as bad in the data quality field with a value of 1. (Good data contains a 0 in this field.) FIPS regularly experiences penetrating radiation which serves as an additional noise source in the start and stop single-coincidence rates. These counts are identified in start and stop rate spectra as relatively constant streaks across the energy spectrum, because they bypass the electrostatic analyzer energy selction when they pass through the FIPS solid structures to trigger the detectors. Typically, these signals do not occur in double-coincidence and therefore do not affect the science data. (That is, they do not generate PHA events or add to the valid event or proton rate.) When double-coincidences do occur, they are often so short in duration (< 1 min) that they can be ignored in all but the most fine time scale analysis. Occasionally, events occur that are of sufficient intensity and duration as to make the double coincidence data unusable, such as long duration solar energetic particle (SEP) events. These events should be excluded from science analysis and are listed in the table below. Start time End time Description ----------------- ----------------- ----------------------------- 2011-155T11:37:00 2011-161T07:00:00 High intensity SEP event 2011-155T15:00:00 2011-159T00:00:00 High intensity SEP event 2011-266T07:00:00 2011-266T12:00:00 High intensity SEP event 2011-277T01:00:00 2011-278T17:00:00 High intensity SEP event 2011-308T01:00:00 2011-308T20:00:00 High intensity SEP event 2012-028T01:00:00 2012-031T09:00:00 High intensity SEP event 2012-065T10:30:00 2012-071T10:30:00 High intensity SEP event 2012-148T11:00:00 2012-150T21:00:00 High intensity SEP event 2012-194T16:40:00 2012-196T05:20:00 High intensity SEP event As of the 10th PDS delivery, FIPS CDR data has a new quality flag system, which automatically flags SEP events and other issues which would affect data quality. This quality flag is a bit field, with each bit set signifying the condition detailed below: Flag Bit Position Decimal Value ------------------------------ ------------ ------------- Bad data (reason undefined) 0 1 PHA hot pixel* 1 2 Scan hard limit reached* 2 4 SEP event 3 8 Start rate anomaly* 4 16 Instrument off 7 128 Bad data (manually marked bad) 15 32768 Multiple conditions set multiple bits, effectively adding the numbers in the value column. (This is the same as performing a logical OR on the binary values.) For example, if PHA hot pixel and SEP event are both set, the flag will have the decimal value 10 (binary: 1010). If the start rate anomaly and scan hard limit reached flags are set in addition, the decimal value would be 30 (binary: 11110). For most science uses, only data with a quality flag value of 0 should be used. However, data with the flags marked with '*' above is often usable for science. Users should consult with the instrument team for details. From May-Sept 2013, MCP voltages higher than the nominal -2520V were tested on FIPS with a goal of recovering counting efficiency lost through use thus far in the mission. Since the counting efficiency is a little different for each of these voltages, users are advised to consult the actual MCP voltage stored in housekeeping when using data from this period. An extensive revision of FIPS efficiencies was implemented for delivery 12. These efficiencies incorporate in-flight from the orbital mission as well as ground calibration data. This release represents a significant improvement in the calibration of these CDR values. During 05-07 Mar 2015, FIPS post-acceleration voltage was raised in steps from the 10.5 kV run throughout the orbital mission to 13 kV. This change was made to increase time-of-flight resolution and had been delayed until the end of mission for risk reduction. This new voltage has been included in the relevant processing in this data set. However, it must also be included in any user processing which makes use of ion total energy in the time-of-flight telescope. Limitations =========== This data set is minimally processed data. The data are received from the spacecraft telemetry and ingested into the MESSENGER Science Operations Center (SOC). "