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We strongly recommend using the original EPPS_DDR_SIS.DOCX or PDF version
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MESSENGER:
Software Interface Specification for the
Derived Data Records of the Energetic Particle and Plasma Spectrometer
Version 2C
Prepared by
George Ho, Lawrence Brown, Lillian Nguyen, Michele Gannon, and Michael Reid
Johns Hopkins University Applied Physics Laboratory
Jim Raines
University of Michigan
Document Review
This document and the archive it describes have been through PDS Peer Review
and have been accepted into the PDS archive.
George Ho, MESSENGER EPPS Instrument Scientist, has reviewed and approved this
document.
Jim Raines, MESSENGER FIPS Instrument Scientist, has reviewed and approved
this document.
Susan Ensor, MESSENGER Science Operations Center Lead, has reviewed and
approved this document.
Table of Contents
1 Purpose and Scope of Document 6
1.1 Purpose 6
1.2 Scope 6
2 Applicable Documents 7
3 Relationships with Other Interfaces 8
4 Roles and Responsibilities 8
5 Data Product Characteristics and Environment 8
5.1 Instrument Overview 8
5.1.1 FIPS Overview 8
5.1.2 EPS Overview 10
5.2 Data Product Overview 13
5.2.1 EPS Data Products 13
5.2.2 FIPS Data Products 15
5.3 Data Processing 21
5.3.1 Data Processing Level 21
5.3.2 Data Product Generation 22
5.3.3 Data Flow 22
5.3.4 Labeling and Identification 24
5.4 Standards Used in Generating Data Products 35
5.4.1 PDS Standards 35
5.4.2 Time Standards 36
5.4.3 Coordinate Systems 37
5.4.4 Data Storage Conventions 37
5.5 Data Validation 37
6 Detailed Data Product Specification 38
6.1 Data Product Structure and Organization 38
6.2 Handling Errors 39
6.3 Data Format Description 39
6.4 Label and Header Descriptions 39
6.5 File Naming Conventions 42
6.6 Archive Volume and File Size 44
6.7 Directory Structure and Contents for EPPS Documentation Volume 45
6.7.1 Directory Contents 45
6.8 Directory Structure and Contents for EPPS Data Volume 47
6.8.1 Directory Contents 47
7 Archive Release Schedule to PDS 48
8 Appendices 49
8.1 EPS_PITCH_ANGLES.FMT Table Columns 49
8.2 EPS_PASD_NUMERIC_DDR.FMT Table Columns 49
8.3 FIPS_PCHANG_DDR.FMT Table Columns 50
8.4 FIPS_ERPCHANG_DDR.FMT Table Columns 51
8.5 FIPS_ESPEC_DDR.FMT Table Columns 52
8.6 FIPS_NOBS_DDR.FMT Table Columns 52
8.7 FIPS_ARRDIR_DDR.FMT Table Columns 53
8.8 FIPS_FLUXMAP_DDR.FMT Table Columns 54
8.9 FIPS_NTP_DDR.FMT Table Columns 55
8.10 FIPS_ROTMSO_DDR.FMT Table Columns 56
8.11 SPICE Kernel Files Used in MESSENGER Data Products 56
8.12 CODMAC/NASA Definition of Processing Levels 57
8.13 MESSENGER Glossary and Acronym List 58
Table 1 Revision History
Version
Author
Date
Description
Sections
1A
L. Nguyen
5/22/2012
Initial revision
All
1B
M. Gannon
5/25/2012
Minor updates from APL team review
All
1C
J. Raines
M. Gannon
10/17/2012
Updates from the EPPS PDS Peer Review of the Sample Archive for DDR
All
1D
P. Bedini
1/29/2013
Editorial updates
All
1E
M. Reid
1/29/2013
Replaced text indicating a draft version of this document with approved &
release version.
Document Review, pg. 2
1F
J. Raines
M. Gannon
11/06/2013
Updates to incorporate new FIPS Advanced Products
All
1G
G. Ho
J. Raines
S. Ensor
1/17/2014
Updates to DDR descriptions and applicable documents
1.2, 2,
5.2.1
1H
J. Raines
M. Reid
6/13/2014
Added information about the FIPS Viewing Normalization products; fixed larger
document formatting.
5.2.2,
5.3.4, 6.5,
6.8, 8.7,
8.8
1I
M. Reid
7/16/2014
Removed references to the FIPS Pixel FOV table. They were moved to the CDR
SIS. Corrected document volume directory structure diagram.
5.2.2.6, 5.3, 6.5, 6.7, 8
1J
J. M. Raines
M. Reid
11/19/2014
Modified to incorporate substitution of FIPS_ARRDIR product with FLUXMAP and
addition of ERPCHANG product. Added ERPCHANG product. Removed FIPS_FOVPIX
directory (FIPA_* files moved to Document Vol. CALIBRATION). Modifications to
ROTSMO label. Formatting.
5.1.1,
5.2, 5.3.4, 6.8, 8.3, 8.7.
1K
J. M. Raines
M. Gannon
1/27/2015
Edits to FIPS Flux Map and FIPS Pitch Angle product descriptions. Correction
of minor typographical errors.
5.2.2.3, 5.2.2.5
1L
S. Ensor
1/16/2016
Final edits (partial)
All
1M
J. M. Raines
M. Gannon
1/28/2016
Final edits
1.1.4 and others
1N
M. Reid
8/10/2016
Added description of the new Daily Pitch Angle Spectrogram products.
1.2, 5.2, 5.3, 6.5, 6.8, 8.2
2A
2B
M. RG. Ho, M. Reid, S. Ensor
01/10/2017
Revisions based on the November 2016 PDS peer review. Daily EPS pitch angle
spectrogram products added.
All
2C
M. J. J. Raines
02/10/2017
Added further discussion of the FIPS data.
5.2.2.1
Purpose and Scope of Document
Purpose
This document serves to provide users of the MErcury Surface, Space
ENvironment, GEochemistry, and Ranging (MESSENGER) Energetic Particle and
Plasma Spectrometer (EPPS) data products with a detailed description of the
EPPS instrument, data product generation, validation, and storage. Note that
the EPPS is made up of two instrument subsystems, the Fast Imaging Plasma
Spectrometer (FIPS), and the Energetic Particle Spectrometer (EPS). The FIPS
and EPS are described in individual sections within this document. They are
referred to separately when necessary and referred to as the EPPS instrument
when dealing with areas common to both instruments. The FIPS covers the lower
energy range of particles and measures the mass per charge (m/q), energy per
charge (E/q), and incoming direction of each charged particle. The EPS covers
the higher energy range and measures mass, energy, and incoming direction of
each particle. The MESSENGER EPPS data products are deliverables to the
Planetary Data System (PDS) and the scientific community that it supports. All
data formats are based on the PDS standard.
Scope
The EPPS science data are divided into two categories: Level 2 edited raw data
(referred to as experiment data records or EDRs) and processed data (referred
to as reduced data records or RDRs). RDRs are generated from EDRs, and
represent data calibrated to a physical unit such as particle intensity (Level
3), resampled Level 4 data products, or derived Level 5 data products. RDRs
consist of Calibrated Data Records (CDRs), Derived Data Records (DDRs), and
Derived Analysis Products (DAPs). This Software Interface Specification (SIS)
describes the EPPS DDR data products.
For EPS, DDRs consist of three products: pitch angle values, pitch angle
distribution spectrograms over selected ranges of energies for selected time
periods, and daily pitch angle distribution spectrograms. For FIPS, DDRs
consist of seven products that provide data for spatial and temporal
distributions of observed density for major ion species, and for selected ion
species and time periods, energy spectra, pitch angle distributions, ion flux,
density, temperature, and pressure, and viewing normalizations for each energy
scan. The DDR data were delivered to the PDS as CODMAC (Committee on Data
Management and Computation) Level 4 data. EPPS's DDRs are formatted to include
standard PDS labels. A detailed description of all data products in the EPPS
DDR follows.
In addition, this SIS describes the EPPS documentation volume, which contains
products related to both the EDR- and RDR-level archives. The contents of the
documentation volume enables one to conduct useful analysis of the DDRs. The
documentation volume is described in greater detail in section 6.6.
Applicable Documents
The MESSENGER EPPS SIS is responsive to the following documents:
Planetary Data System Standards Reference, Feb 27, 2009, Version 3.8. JPL
D-7669, Part-2.
MESSENGER Data Management and Archiving Plan. The Johns Hopkins University,
APL. Document ID number 7384-9019
MESSENGER Mercury: Surface, Space Environment, Geochemistry, Ranging; A
mission to Orbit and Explore the Planet Mercury, Concept Study, March 1999.
Document ID number FG632/ 99-0479
[PLR] Appendix 7 to the discovery program Plan; Program Level Requirement for
the MESSENGER Discovery project; June 20, 2001.
The following documents may be referenced for details on the EPPS instruments:
Livi et al., MESSENGER Energetic Particle Spectrometer (EPPS/EPS) Calibration
Report, 2004 (at PDS Geosciences node: messgc_0001/EPS/EPS_CAL_RPT).
Zurbuchen et al. (The Fast Ion Plasma Spectrometer (FIPS) calibration report,
MESSENGER Project report, 2004)
Andrews et al. (The Energetic Particle and Plasma Spectrometer Instrument on
the MESSENGER Spacecraft, Space Science Reviews Volume 131, Numbers 1-4,
August 2007)
Raines et al. (Distribution and compositional variations of plasma ions in
Mercury's space environment: The first three Mercury years of MESSENGER
observations, Journal of Geophysical Research, 118, p1604-1619, 2013)
Gilbert et al. (Background noise in space-based time-of-flight sensors,
Reviews of Scientific Instrumentation, in review, 2014)
Gershman et al. (Post-processing modeling and removal of background noise in
space-based time-of-flight sensors, Deep Blue, 2013,
http://hdl.handle.net/2027.42/100358)
Raines et al. (MESSENGER observations of the plasma environment near Mercury,
Planetary and Space Science 59, p2004-2015, 2011)
Ho et al. (Spatial distribution and spectral characteristics of energetic
electrons in Mercury's magnetosphere, J. Geophys. Res.,
doi:10.1029/2012JA017983, 117, 2012)
Gershman et al. (Magnetic Flux Pile-up and Plasma Depletion in Mercury's
Subsolar Magnetosheath, Journal of Geophysical Research: Space Physics, 118,
p7181-7199, 2013)
Slavin et al. (MESSENGER Observations of Extreme Loading and Unloading of
Mercury's Magnetic Tail, Science, 329, p665-668, 2010, doi:
10.1126/science.1188067)
Ho et al. (Observations of Suprathermal Electrons in Mercury's Magnetosphere
during the three MESSENGER Flybys, Planetary and Space Sci., 59, p2016-2025,
2011)
Relationships with Other Interfaces
The EPPS DDR data products were stored at the MESSENGER Science Operations
Center (SOC) during the MESSENGER mission. The data products were transferred
to the PDS Planetary Plasma Interactions (PPI) Node according to the delivery
schedule in section 7. The data in the DDR files is stored in PDS ASCII TABLE
objects unless stated otherwise (section 5.2).
Roles and Responsibilities
The roles and responsibilities of the instrument teams, The Johns Hopkins
University Applied Physics Laboratory (APL), Applied Coherent Technology
Corporation (ACT), and the Planetary Data System (PDS), are discussed in
sections 5.3.2 and 5.3.3.
Data Product Characteristics and Environment
Instrument Overview
FIPS Overview
The Fast Imaging Plasma Spectrometer (FIPS) measures the energy per charge
(E/q), time-of-flight (TOF), and incident angles for plasma ions entering the
sensor. Intensities, velocity distributions, and mass per charge (m/q)
distributions are derived from these measurements and make up FIPS primary
science data. These data are used to understand the kinetic properties,
angular distributions, and composition of Mercury magnetospheric ions, and
contribute to the characterization of the planetary magnetic field.
Ions measured by FIPS pass through 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 FIPS acts as a wide-angle lens for ions, with a 1.4 sr field of
view. It allows only ions with a specific E/q band to enter through its output
plane. This band is stepped through 64 values to complete one measurement
cycle (scan), nominally from 0.046-13.3 keV/e. FIPS is normally operated in
one of two stepping rates: one step per second (normal mode), or one step per
100 milliseconds (burst mode). When delays due to high-voltage ramp-ups are
included, these result in cycle times of 64 sec and 8 sec, respectively. The
operation of FIPS is highly configurable via table upload. The time spent in
each step can, in principal, be set to arbitrary values, different for each
step (nominally set at 100ms/1s for burst/regular mode). Associated with each
E/q step is a deflection voltage, a threshold, a settling time, and an
integration (dwell) time.
Ions exit the output plane of the ESA and are then accelerated in the post
acceleration chamber. This acceleration is done to give low-energy ions
sufficient energy to penetrate the carbon foil. The acceleration also helps to
reduce energy straggling and angular scattering - effects that cause
degradation in mass resolution and imaging. When ions exit the carbon foil,
secondary electrons are liberated. These electrons travel to the Start MCP
(microchannel plate), providing a timing-start signal and incident angle
information via impact location on a position-sensing anode. The ion then
travels through the TOF chamber and strikes the Stop MCP, providing a
timing-stop signal and allowing computation of TOF. From E/q and TOF, m/q can
be computed. FIPS can measure species from H to Fe, 1-60 amu/e (or higher).
Individual ions are identified in FIPS data from their E/q and TOF
measurements. A simple model is used to predict the TOF range expected for
each ion as a function of E/q, referred to as the E/q-TOF track for that ion.
This model includes the effects of energy lost upon passage through the carbon
foil, as well delays due to electron flight time and electronic processing.
All events with measured TOF within the predicted range for a particular ion
are assigned to that ion. To improve signal to noise, E/q-TOF tracks for some
ions are grouped together. In this dataset, H+, He+, and He2+ are assigned
from their respective individual ion tracks. Two ion groups are defined: O+
group (m/q = 16 - 20; including O+ and water group ions) and Na+ group (m/q =
21-30; including Na+, Mg+, and Si+). Additional details concerning this
process are given in [8].
Figure 1 Cross-section of the FIPS sensor showing both the ESA and TOF section
[7]. Ions are analyzed by their energy per charge, 2D position, and total time
of flight.
FIPS uses a double coincidence technique to greatly reduce background noise.
However, spurious double-coincidence counts still do occur. These counts come
from two main sources: the extension of very high count proton measurements
into other times of flight, and the release of small numbers ions from surface
processes within the instrument [9]. While all major ion species reported here
can be analyzed from the raw data, accuracy is significantly improved by
removing these spurious counts. A detailed noise model and removal method has
been developed [10] and is employed on the data in this work at the individual
scan level.
After species are identified in E/q-TOF space and noise counts removed, the
resulting counts for species s (Ci,s) at each measured (E/q)i are transformed
to phase space density (fi,s) in units of s3 m-6. Using the CDR fluxes (Ji,s)
in sec-1 cm-2 sr-1, this conversion is achieved using the following
relationship:
f_(i,s)=J_(i,s) m_s/(v_(i,s)^2 C)
where vi,s is velocity, ms is ion mass (in amu) and C is a unit conversion
factor, 1.6022 10-20 (cm2 s keV)-1 .
The details of the conversion of counts to phase space density are provided in
the EDR2CDR document, available in the CALIBRATION directory of the EPPS
documentation volume.
Details of FIPS operations can be found in [7].
EPS Overview
EPS is a compact TOF telescope with two main components: a TOF section and a
Solid State Detectors (SSD) array. The SSD array comprises six ion-implanted
planar silicon detectors, each with four pixels (two dedicated to ion
measurements and two to electron measurements) for a total of 24 SSD elements.
Particles enter the system through a mechanical collimator that delimits the
look direction into the instrument. Particles that pass through the collimator
then transit through a thin, composite Start foil (polyimide + aluminum, 10
?g/cm2) and onto the TOF region of the instrument.
Figure 2 Cross-section of the EPS sensor. The particle tranverses from left to
right in the figure and terminates at the SSD. The primary particle generates
secondary electrons when it passes through both the front and stop foil. These
electrons are being steered toward the anodes at the bottom of the figure.
Electrons are released from the inner surface of the Start foil and focused to
a well-defined region on an MCP to generate the START signal in a dedicated
anode. The incident ions are not significantly affected by the electric fields
of the focusing optics. After a 6 cm flight path, ions traverse the Stop foil,
which is a polyimide + palladium (19 ?g/cm2) composite foil. The secondary
electrons released by the stop foil are steered to the MCP and generate the
STOP signal. Electron trajectory simulations show that there is less than 2 ns
dispersion in the transit time of the secondary electron from the foil to the
MCP. Sub-nanosecond dispersion is required so as not to misidentify ion
species. If both a START and STOP signal (double coincidence) are registered,
then the time, t, for the particle to travel a known distance (d=6 cm) can be
determined. For triple coincidence we must have the START, STOP, and also the
energy measured (Emeas) by the SSDs. Using these measured parameters, we can
calculate the mass (M) and the incident energy (E) of each ion using the
following equations:
Etrue takes into account the small energy loss of the ions passing through the
stop foil, and the energy loss and pulse-height defect in the SSDs. EToF takes
into account the even smaller energy loss or gain in the start foil, and may
also include up to ~2.5 keV electrostatic pre-acceleration of ions that remain
charged on exiting the start foil. If the energy of the incident particle is
not large enough to trigger the SSD, then only t is measured and the pulse
height of the start anode is used to discriminate whether it is a light (M~1
amu), or heavy (M ❯ 1 amu) ion. At the same value of TOF, heavy ions have been
shown to generate substantially more secondary electrons than do protons.
Besides composition measurements, the particle's angular direction can be
determined. The pair of start and stop anodes provide the polar entrance angle
of the incident particle. The polar angle of +80 to -80 is divided into six
equal sectors (nominally 27).
Electron measurements
Energetic electrons have higher penetration power than ions at the same
energy. The SSDs dedicated to electron detection in EPS are covered by a thin
layer (flashing) of 1?m of aluminum. This dead layer stops protons with energy
less then ~250 keV; Electrons, on the other hand, lose less than 10 keV by the
interaction with this dead layer. Electrons are identified in EPS by the
presence of an energy signal. The TOF spectra collected in the adjacent SSD
(without flashing) are used during ground data analysis for checking and
correcting for the proton contamination.
"Calibration" for a particle instrument like EPS means determining the
following:
Transfer function from counts into flux (physical units)
Characteristic of "Rate-out" versus "Rate-in"
Response to low energy and high energy particle background
Response to visible and ultraviolet light
Response to high magnetic field
All these functions need to be characterized and the relevant parameters need
to be determined before flight.
Transfer Function
Flux, differential intensity, and phase space density
The number of particles N that traverse an area A during a time t can be
characterized by the flux F [1/cm2/s]
N= A * t * F
or by the intensity I [1/cm2/s/sr]
N= A * t * ? I cos() d?
where ? is solid angle and is angle to the area normal. Here, the geometric
characteristics of the sensor determine the limits on the integration.
Often used is the quantity differential intensity f [1/cm2/s/sr/keV], defined
as the number of particles with energy between E and E+?E that traverse the
area A during the time t, where
N(E)=f(E) * A * t * ?? * ?E
In three dimensions, with ? being the polar angle and f the azimuthal angle of
a polar reference system:
d3N(E,?,f)=f(E, ?, f) * A cos() * t * dE cos ? d? df
Note that f(E, ?, f) is related to the phase-space density psd (number of
particles in the configuration space element d3R and with velocity between v
and v+ d3v) by the simple relationship in the non-relativistic limit (valid
for ions measured by EPS but not for the higher energy electrons):
psd(s3/ cm6)=f(1/cm2/s/sr/keV) * m/v2
For relativistic particles, one generally utilizes momentum space rather than
velocity space, and the corresponding expression is:
psd(s3/gm.cm6) = f(1/cm2/s/sr/keV) / p2
Where "p" is momentum.
Definition of sensor transfer function and geometric factor
The number of counts N of particles of mass m, in the energy band around mean
energy E, angular band ?? around mean polar direction ?, and angular band ?f
around the mean azimuthal direction f, measured by the instrument during the
time dt can be expressed as:
N(E, ?, f; m) = dt * ??E ??? ??f f(E, ?, f; m) * A cos() * dE cos ?
d? df
If f(E, ?, f) is a Dirac d function (monoenergetic, infinitely narrow beam),
then
N(E, ?, f; m) = dt * f(E, ?, f; m) * G(E, ?, f; m)
Where G(E, ?, f; m) [cm2 sr keV] is the transfer function of the instrument.
In the other limit, when the flux is completely isotropic (all directions the
same)
N(E; m) = dt * f(E; m) * GF(E; m)
GF is called geometric factor. In this representation we also include the
species and energy dependence, which is a measure of the efficiency of the
system (count rate/flux), and typically is a function of energy and species.
Since the true geometric factor (or GF') is only the geometric mean (constant
for energy and species) of the entrance system, we can rewrite GF = GF'*?(E,
m, ?, f).
The goal of the calibration is to characterize the function GF(E, ?, f; m), so
that from measurements of the count rates it is possible to constrain f(E, ?,
f; m). Note that an exact inversion of the integral is rarely possible, and we
can compute only the coefficients of some tailored expansion of f(E, ?, f; m),
such as in spherical harmonics (Legendre polynomials). The accuracy of these
coefficients depends on both the raster coverage of the measurements and on
the calibration.
Collimator
The EPS collimator consists of four concentric half circular plates that have
holes aligned with a common point of origin at the center of the EPS TOF
telescope. The size and number of collimator holes define the geometric factor
GF of the instrument. The many-holes collimator design minimizes the
scattering of ions and electrons at the collimator while restricting the
field-of-view (FOV) of the instrument.
GEANT4 simulation (which can stimulate the full GF(E, ?, f; m), not just the
GF') shows that the geometry factor for the total SSD area to be 0.016 cm2 sr.
The simulation accounted for gaps between the detectors, but did not allow for
the guard ring dead area between the large and small pixels (~1mm wide) or the
losses in the two grids used to mount the thin foils. Hence, before grid
losses, the total large pixel geometry factor is therefore GFSSD = 0.0152 cm2
sr, and the small pixels would be 0.0008 cm2 sr. The grid losses are actual
blockages, so these should be included in the geometry factor. EPS used
40-lines-per-inch grids on the foils that are 86% transmissive. Therefore, for
the 12 large pixels, we have a total geometry factor of 0.862x0.0152, or 0.011
cm2 sr, and each large pixel is 1/12 of that, or GFSSD-Large = 0.001 cm2 sr.
For the 12 small pixels, we have a total geometry factor of 5.6x10-4 cm2 sr,
or GFSSD-Small = 4.7x10-5 cm2 sr per pixel. The current simulation does not
model the scattering of low energy ion and electron in the collimator; hence
the current value of GFSSD is constant with energy and look direction.
Disclaimer: EPS suffered a high-voltage failure shortly after launch [15];
subsequently the TOF section never operated in flight. Hence the following
paragraph does not apply to the EPS flight data, we include here for
completeness only.
GFTOF for the Low Energy Ions (TOF-only) is roughly twice the SSD values, or
~0.03 cm2 sr. Note that the needed Transfer Factor GF depends also on the
counting efficiency ? (E, m, ?, f) which depends, in turn, on species and
instrument mode. However, these values were never conclusively determined.
During the time of instrument check out shortly after launch, EPS's TOF
section suffered a failure [15]; subsequently, EPS lost its ability to measure
ions by elemental mass species. All in-flight EPS data contains null TOF
values, hence, EPS can now only measure
N(E) = dt * f(E) * GFSSD
GFSSD is now the geometric factor and represents a measure of the efficiency
of the system (count rate/flux), and is constant with look direction, energy
and species. This is the standard approximate conversion of count rate to
intensity assuming the channel efficiency is part of the geometry factor. The
shape of the energy spectrum also affects the response, here we assume a
monotonic energy spectra within the energy width of the channel.
Data Product Overview
The DDR data products generated by the EPS and FIPS subsystems are described
in this section. For all of the DDR products there is a detached PDS label
file, which describes the contents of one data file. Each label file has 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 ASCII tables.
Each data file contains the data collected on a given Earth day.
EPS Data Products
The EPS portion of the data archive consists of tables of EPS pitch angle
values, pitch angle distribution function spectrograms in the form of browse
plots, and daily pitch angle distribution spectrograms in the form of browse
[SE1]plots and text data files. These data products are derivate from the
"Shaped" channel on EPS which is an integrated (hardware) channel. The
hardware channel responded to all particles (ion and electron) that are above
the threshold (~30 keV). Our experience at Mercury's magnetosphere is that the
primary particles are mostly energetic electrons. Please note that the D03
detector on the EPS has a very high background and is not useable for any of
these science data products.
Pitch Angle Computation
The pitch angle is defined as the instantaneous angle between the particle
flow direction and the measured in-situ magnetic field, with 0 degrees being
where the particle is traveling along the field and 180 degrees where the
particle is traveling in the opposite direction. Both vectors (the particle
flow direction and the magnetic field) are measured in the spacecraft frame.
The pitch angle values are calculated using the EPS odd-shaped channels.
These hardware channels correspond to ions or electrons that are above the
instrument threshold (nominally ~35 keV), and are not affected by
prioritization in the instrument software. For a rapidly falling energy
spectrum, these counts would be dominated at the lowest energies. These values
should be used in conjunction with the rate channels for which intensity is
computed. The particle flow direction for each of the six EPS look directions
is obtained by using the MESSENGER SPICE pointing kernels (c-kernels) and the
EPS frame kernel. The magnetic field measurements are taken from MESSENGER
Magnetometer (MAG) Level 1 1-second averaged data; see the MAG instrument DDR
SIS.
Pitch Angles Product
The pitch angle value tables contain the pitch angle for each of the six look
directions reported at the same cadence as the EPS LoRes Spectral rate
measurements (see EPPS CDR SIS document). Each file thus has a one-to-one
relationship with a corresponding LoRes spectral file. Constant normalization
factors and background subtractions have been applied to these channels to
offset any bias in the threshold setting. Channel 01 is set to be one and all
other channels are normalized to that. The channel chosen for normalization
is arbitrary and does not impact the use of these data products as they are
supposed to be used in conjunction with the properly calibrated rate channels.
The formula used is Adjusted Value = Scaling * Raw Value + Offset. The
constant scaling and offset values are given in Table 2. Please note that the
D03 detector on EPS has a very high background and is not useable for any
science data product.
Select Pitch Angle Distribution Spectrogram Product
The pitch angle distribution shown in the pitch angle spectrogram browse
[SE2]plots is plotted using the pitch angle values and time-averaged within
the time interval accordingly.
We averaged the particle measurement in 120-second bins. Pitch angle bins are
22.5 degrees wide, and run from 0 to 180 degrees. For the pitch angle
distribution spectrogram, the color scale is normalized to the maximum counts
for the time interval covered by the current plot (i.e. the intensity color
scale varies between plots). The products provided in the
EPS_PITCH_ANGLES_SPECTROGRAM directory in this volume are selected based on
the criteria outlined by Ho et al. [JGR, 2012] on events that are at least 10
times above the instrument background at the lowest energy channel 36-57 keV.
Pitch angle spectrogram products are provided for all orbital periods in the
EPS_PA_DAILY_SPECTROGRAM directory.
Channel Name
Scaling
Offset
SHAPED_COUNTS D00
1.0412691533565521
15.11127820611
SHAPED_COUNTS D01
1
0
SHAPED_COUNTS D02
0.7014738321304321
10.141375184059143
SHAPED_COUNTS D03
SHAPED_COUNTS D04
1.338530421257019
18.39651709794998
SHAPED_COUNTS D05
1.3527332693338394
7.795897737145424
SHAPED_COUNTS D06
1.4293411076068878
27.3230662047863
SHAPED_COUNTS D07
0.805070623755455
3.0807372108101845
SHAPED_COUNTS D08
0.9233275651931763
32.62595450878143
SHAPED_COUNTS D09
0.5404207110404968
-0.39973045140504837
SHAPED_COUNTS D10
0.31776440143585205
22.942654877901077
SHAPED_COUNTS D11
0.15649390034377575
-22.306587459519506
Table 2 Constant values used to adjust the count rate for the shaped channels.
D01 is the channel to which all others were fit in order to arrive at these
values, while D03 is unlike the others and cannot be fit, so it remains
unadjusted.
Daily Pitch Angle Distribution Spectrogram Product
The Daily Pitch angle Spectrogram products are similar to the Select products
described above, but are provided as daily products that cover the entire
orbital phase of the mission. Additionally, a text data file (.TAB)
accompanies each browse plot. The data file contains the same pitch angle
distributions as plotted in the browse [SE3]product (.PNG), but as data
points.
FIPS Data Products
Except where noted below, these data products are derived from individual
event (PHA) words, which have full angle and TOF information. Using PHA words
enables the finest possible separation into ion species as well as
distinguishing incident angles. Noise removal in E/q - TOF space is performed
before accumulation for all ions except H+, for which noise removal is not
needed.
The orbital regions for which data is provided varies by product, as described
below. Within these, data is provided for time steps whenever the instrument
was operating in a nominal mode and when the data was of sufficient quality
for scientific analysis. These conditions are met for the vast majority of
times throughout the mission. In particular, many of these products are
provided in regions determined by hand-picked or modeled bow shock and
magnetopause boundaries. Boundary picking was done by the MAG team at a level
of accuracy sufficient for the relatively low time resolution FIPS data (10s -
60s). Where these were not available, the model given by Slavin et al. [14]
is used.
Differential Energy Flux Spectra
Differential energy flux spectra in units of (keV/e)-1 sec-1 cm-2 sr-1 are
provided for all 5 ion species throughout the entire magnetosphere and
magnetosheath regions crossed by the spacecraft during each orbit. These
spectra cover the full energy per charge range of FIPS, which ws 0.046 - 13.3
keV/e during most of the mission. See the FIPA_EYYYYDOY.DAT file for exact
energy range. They are derived in a manner completely analogous to CDR
differential energy flux spectra (dJi,s/dEi) except that the total number of
PHA event words for a given species at each E/q step is used in place of
on-board accumulated count rates (except protons). See EPPS_FIPS_EDR2CDR.DOCX
for more details.
For protons, this product is derived from on-board accumulated rates just as
for the CDR version, so that for protons only this product is a duplicate of
the CDR version. This duplication was intended to allow users to primarily
use DDR data only in their scientific analysis. However, the differential
energy spectra for protons only are not organized according to the
FIPA_EYYYYDOY.DAT files as are the rest of the ion species in this product.
The protons are instead organized by E/q step, just as they are in the CDR
version. Please refer to the EPPS CDR SIS for more information. The CDR
proton rate spectra product is also needed to determine which of the available
E/q tables to use for all species in this product. This requirement to use
CDR products in conjunction with their DDR counterparts was unintended and
will be removed in a future release.
Observed Density
Observed density (nobs,s, in cm-3) for all ion species is provided for all 5
ion species throughout all orbit regions. This product serves to determine the
spatial and temporal distribution of these ions and is the foundation DDR data
product for FIPS. For protons, this product is derived from on-board
accumulated rates rather than PHA event words, for much higher signal to noise
ratio.
Observed densities are computed from differential energy flux spectra Ji,s in
two stages: First, dJi,s/dEi is converted to phase-space density (fi,s, s3
m-6)
f_(i,s)= 6.2414?10?^19 (m_s/(v_(i,s)^2 ))(?dJ?_(i,s)/?dE?_i )
Second, fi,s integrated over all velocities (vi,s) and solid angle (?O) for a
full scan to yield observed density (nobs,s) for species s
It is important to note that no correction has been made for limited field of
view in this calculation. This correction requires knowledge of the true
velocity distribution function in which the measured particles reside and is
therefore beyond the scope of this data product. The net result is that nobs
values reported are not in general equal to the ambient plasma density. More
information about calculation of nobs and the limited FIPS field of view can
be found in [10, 11].
Angular Flux Maps
Integrated ion flux, Js(?,?), as a function of flow direction in MSO
coordinates are provided for all 5 ion species throughout the entire
magnetosphere and magnetosheath regions crossed by the spacecraft during each
orbit. This product replaces the Arrival Direction Histogram (ARRDIR) product
as it more a more useful representation of plasma behavior. Angular Flux Maps
may be used in conjunction with pitch angle distributions to understand the
location and motion of ions relative to Mercury. The discrete integration of
phase space density (f) is performed over ion speed (v) in the standard way,
leaving the two angular dimensions unchanged:
J_s (?,?)=?_i.giff_(i,s) (?,?)v_(i,s)^3 dv_i
Very low count rates can make this product difficult to interpret. For some
ions, this situation is mitigated by summing over several, often many, FIPS
scans until sufficient counts are available. In other cases, counts for a
particular ion are so low the required number of counts would require
summation over large regions of space, making the arrival directions again
difficult to interpret. Therefore, these cases are not included in the data.
Summing over multiple scans brings with it the need to normalize the arrival
direction distributions for the amount of time that a particular incident
angle could be observed. In normal operations, the MESSENGER spacecraft
rotates around the spacecraft Y-axis (YMSGR) to optimize viewing for different
instruments. FIPS orientation is fixed relative to the spacecraft, so that the
FIPS FOV rotates with the MESSENGER spacecraft. This results in significant
variation in observing time for look directions in MSO coordinates. These
variations in observing time have been normalized out of the fluxes included
in this data product. Despite this normalization, the finite sensitivity of
FIPS can still result in reduced measured ion flux from arrival directions
with low observing time. In practice, this does not usually affect the
typically qualitative interpretation of these maps. The user could mitigate
this effect by reducing the variability of observing time: Only flux from
directions that are viewed within a fixed fraction (e.g. 0.1) of the maximum
observation time for a given time accumulation could be included in arrival
direction histograms. This restriction is not applied to delivered data from
this data product.
The FLUXMAP data product is constructed and normalized as follows:
Two arrays representing a full 4p steradian FOV are created at the 10 native
angle binning of FIPS. This results in an 18 x 36 element array for the polar
and azimuthal angle bins, respectively. The first of these is used for the
average flux, FLUX, while the second is used for the average measurement time,
VIEWTIME.
The FLUX matrix for each energy scan is created from PHAs as follows:
Find the rotation matrix, ROTMSO, (described below) for the day (YYYYDOY) and
index which corresponds to the scan
Form the unit velocity vector:
Convert the incident polar and azimuthal angles of the event from FIPS
spherical coordinates to FIPS Cartesian coordinates. Use the usual manner for
spherical to Cartesian conversion, using 1 for the r component.
Invert the direction by multiplying all components by -1. This changes the
FOV coordinates to flow direction.
Rotate to MSO via multiplication by the ROTMSO.
Convert the resultant MSO vector to spherical coordinates. Round angles down
to the nearest 10.
Add the flux value multiplied by the PHA solid angle into a temporary 18 x 36
matrix using the rounded-down angles.
Convert entire FIPS spherical MCP map to MSO using the steps from (ii) for
each coordinate pair. Round angles down to the nearest 10.
Add the MCP pixel solid angles into a second temporary 18 x 36 matrix using
the rounded-down angles.
Divide the temporary flux by the temporary solid angle,, element-by-element.
The VIEWTIME matrix for each energy scan is created as follows:
Calculate the average step measurement time for the scan
Add that value into every element of the VIEWTIME matrix
Set to 0 any matrix location for which the corresponding solid angle matrix
value is 0 (this will remove unobserved locations from the result).
Sum FLUX and VIEWTIME over all accumulation scans
Form the properly normalized product by dividing (element by element) the
FLUX (summed over scans) and VIEWTIME (summed over scans).
FLUXMAP=(?.gifFLUX)/(?.gifVIEWTIME)
Arrival Direction (Retired Product)
This product class was retired after the Mercury Orbit Year 2 mission phase.
The Angular Flux Map products described in the previous section supersede it.
Since the Arrival Direction products remain in version V1.0 of the data set in
the FIPS DDR archive volume at the PDS, a description of them is retained in
this document.
This product provides observed density as a function of arrival direction in
the instrument frame (incident polar and azimuthal angle) in MSO coordinates
for selected ions and regions around Mercury. The discrete integration of
phase space density (f) is performed in the velocity dimension (v) only,
leaving the two angular dimensions unchanged:
n_(obs, s) (?,?)=?_i.giff_(i,s) (?,?)v_(i,s)^2 dv_i
The above quantity, termed "observed density", is analogous to density in each
angular bin formed only from the counts observed in that bin. It differs from
that performed in the Angular Flux Map product by one power of v which
introduced in that product to change from a density to a flux quantity.
The Arrival Direction Histogram product is identical in several ways to the
Angular Flux Maps product that replaced it: It can be difficult to interpret
due to very low count rates, a problem which is partially mitigated by summing
over FIPS scans. This summing then requires proper normalization, performed
in exactly the same manner as described in detail for Angular Flux Maps. This
product may be used in conjunction with pitch angle distributions to
understand the location and motion of ions relative to Mercury.
The ARRDIR data product is constructed and normalized exactly as described
above for the Angular Flux Maps, with two exceptions (with the ARRDIR array
replacing the FLUXMAP array):
The velocity vector must NOT be inverted by reversing the sign of each
component.
Multiply the weight from each PHA is added into the ARRDIR array. It is not
multiplied by the particle speed. (Modify step 2.b.iv. above.)
Pitch Angle Distributions
For an ion in the presence of a magnetic field, the angle between the velocity
vector and the local magnetic field direction is referred to as pitch angle.
For populations of plasma ions, pitch angle distribution histograms can be
formed by counting the number of ions within a given pitch angle range (PCHANG
data product). This histogram may also be separated into measured E/q bins,
forming energy-resolved pitch angle distributions (ERPCHANG data product).
Pitch angle distributions give information on the velocity of ions along
magnetic field lines, character of velocity distributions and the general
plasma environment. Care must be taken when interpreting pitch angle
distributions in the instrument frame (such as these) when the plasma has a
non-negligible bulk velocity. Both the PCHANG and ERPCHANG products are
provided for all 5 ion species throughout the entire magnetosphere and
magnetosheath regions crossed by the spacecraft during each orbit.
The pitch angle distribution for a given time period consists of a histogram
of these angles in 10 bins for all the ion events (PHA words) in the time
period. Energy-resolved pitch angle distributions are also separated into the
native FIPS E/q stepping bins. Pitch angle distributions are provided for
selected ions and time periods, when sufficient statistics exist to make the
product meaningful for scientific studies.
The PCHANG data product is normalized as follows:
Two arrays representing pitch angles 0-180 are created at 10 binning,
resulting in two 18-element arrays. The first of these is used for the
average flux, FLUX, while the second is used for viewing normalization,
VIEWTIME.
The FLUX array for each energy scan is created from PHAs as follows:
Find the rotation matrix, ROTMSO, (described below) for the day (YYYYDOY) and
index which corresponds to the scan
Form the unit velocity vector:
Convert the incident polar and azimuthal angles of the event from FIPS
spherical coordinates to FIPS Cartesian coordinates. Use the usual manner for
spherical to Cartesian conversion, using 1 for the r component.
Invert by multiplying all components by -1. This changes the FOV coordinates
to flow direction.
Rotate to MSO via multiplication by the ROTMSO.
Average the MAG CDR vectors (already in MSO) that fall within the FIPS scan
time to one value
Calculate the angular separation between this vector and the average MAG
vector. Round down angle to nearest 10.
Add the flux value multiplied by the PHA solid angle into a temporary 18
element array using the rounded-down angles.
Convert entire FIPS spherical MCP map to MSO using the steps from (ii) for
each coordinate pair. Round angles down to the nearest 10.
Calculate the angular separation between the MCP vectors and the average MAG
vector. Round down angle to nearest 10.
Add the MCP pixel solid angles into a second temporary 18 element array using
the rounded-down angles.
Divide the flux temp by the solid angle temp, element-by-element.
The VIEWTIME array for each energy scan is created as follows:
Calculate the average step measurement time for the scan
Add that value into every element of the VIEWTIME array.
Set to 0 any array location for which the corresponding solid angle array
value is 0 (this will remove unobserved locations from the result).
Sum FLUX and VIEWTIME over all accumulation scans
Form the properly normalized product by dividing (element by element) the
FLUX (summed over scans) and VIEWTIME (summed over scans).
PCHANG=(?.gifFLUX)/(?.gifVIEWTIME)
The ERPCHANG product is formed in an analogous fashion, with the additional
separation by E/q step. In this case, the weighting value in the 'FLUX'
numerator is average phase space density.
Kinetic Properties
Under several conditions, full number density, n, temperature, T, and
pressure, P, can be calculated directly from counts. (In contrast, when these
conditions are not fulfilled, only the partial, observed densities, described
above in 5.2.2.2, can be determined.) The conditions are as follows:
There must be sufficient counts to produce a well-defined energy spectrum.
When necessary, counts from multiple scans are summed to meet this criterion.
The plasma must be subsonic. That is,
where vb is the plasma bulk velocity and Vth is the plasma thermal velocity.
The plasma must be nearly isotropic. That is,
where T? is the plasma temperature perpendicular to the magnetic field and T||
is the plasma temperature parallel to the magnetic field.
This data is provided where these assumptions are most likely to hold: a)
throughout the magnetosphere and b) the dayside magnetosheath within a 45
cone angle around the XMSO axis. Furthermore, the data are averaged over
multiple FIPS scans so as to minimize the effect on the recovered n and T of
transients (e.g. high speed flows) which violate the assumptions. However,
for studies involving features near the time scale of the averaged data and/or
inside the magnetosheath, users are strongly cautioned to evaluate the
validity of the assumptions themselves. This is most easily done by comparing
velocity distribution functions, computed from differential energy flux
spectra and averaged to the same period as this data, to those formed from a
non-drifting Maxwell-Boltzmann velocity distribution formed from the recovered
n and T (with bulk speed of zero).
For protons, this product is derived from on-board accumulated rates rather
than PHA event words, for much higher signal to noise ratio. Data is summed
over multiple scans to increase signal to noise. Furthermore, this data is
produced only those accumulations which exceed a minimum count level (20
counts). Extensive testing has shown that computing these products from PHA
event words for ions heavier than protons is not practical at fixed time steps
of the order of a few minutes. Therefore, these ions are not included in
this product.
When these conditions are fulfilled, we compute n and vth directly from
measured velocity distribution functions (formed from differential energy flux
spectra) using a numerical method of solving the system of moment equations
[Gershman et al., 2013]. T and P are then calculated using the usual
relations:
where kb is the Boltzmann constant. The units of the recovered plasma
parameters are cm-3, MK, and nPa for n, T, and P, respectively. The quoted
uncertainties of these parameters are a function of only number of counts used
to create each distribution, following Gershman et al., 2013. There are
small additional uncertainties that result as the measured energy spectra
approach the limits of conditions (2) and (3) above. These additional
uncertainties are difficult to quantify and not included in the reported
uncertainties.
Viewing Normalization
The FIPS Viewing Normalization data product contains a rotation matrix
(ROTMSO) from FIPS cartesian to MSO coordinates, for each FIPS energy scan.
This matrix can be used to rotate ion incident angles in CDR PHA data into MSO
coordinates needed for producing normalized directional maps (e.g. FLUXMAP or
PCHANG) for arbitrary time resolutions, in multiples of 10s.
Data Processing
Data Processing Level
There is one EPPS PDS Documentation Archive Volume and one EPPS PDS Data
Archive Volume. The data volume contains level 4 CODMAC data products, also
known as DDRs. Each product has a unique file name and conforms to the file
naming convention in section 6.5. All DDR products were stored at the
MESSENGER Science Operations Center (SOC) during the MESSENGER mission.
Volumes were transferred to the PDS PPI Node following the procedure in
section 5.3.3.
Data Product Generation
The EPPS DDR files were produced by the EPS and FIPS teams. A Java program
derived from the MIDL (Mission Independent Data Layer) analysis software
developed by APL was used to generate the DDRs. The FIPS data were produced
using Interactive Data Language (IDL) software routines developed at the
University of Michigan. The DDR data products were made available to the
MESSENGER Science Team for initial evaluation and validation. At the end of
the evaluation and validation period, the data were organized and stored in
the directory structure described in section 6.8 for transfer to the PPI Node.
The transmittal process is described in section, 5.3.3. An initial release of
the documentation volume accompanied the initial release of the data volume.
Thereafter, updates to the documentation volume were made with each data
delivery to document the data quality for the delivery, changes to products
including calibration updates, and other updates as appropriate. PDS provides
public access to the data products through its online distribution system.
These products support engineering analysis, direct science analysis, and
construction of other science products.
Data Flow
The MESSENGER SOC operates under the auspices of the MESSENGER Project
Scientist to plan data acquisition, generate, and validate data archives. The
SOC supports and works with the Mission Operations Center (MOC), the Science
Team, instrument scientists, and the PDS.
Figure 1 MESSENGER data flow shows the flow of data within the MESSENGER
project and out to PDS. The MOC handles raw data flow to and from the
MESSENGER spacecraft and the SOC converts the raw telemetry into EDRs, which
are subsequently converted into CDRs and DDRs by the Science Team.
Documentation, CDRs, and DDRs are delivered to the PDS Planetary Plasma
Interactions (PPI) node. All SPICE kernels used in CDR and DDR processing are
delivered to the PDS Navigation and Ancillary Information (NAIF) node. The
delivery process is detailed below.
The MESSENGER SOC delivered data for the EPPS DDR data volume to the PDS PPI
Node in standard product packages. Each package comprises data and ancillary
data files, organized into directory structures consistent with the volume
design described in section 6.8. The initial release contained the documents
and required files for the EPPS documentation volume, organized into directory
structures as described in section 6.7. Subsequent releases to the EPPS
documentation volume contained updates as appropriate.
In preparation for delivery, the directory structure is compressed into a
single "zip archive" file for transfer to the PDS node. The zip archive
preserves the directory structure internally so that it can be recreated after
delivery to the PDS node. Also included in the transfer is a checksum file
created using the MD5 algorithm. This provides an independent method of
verifying the integrity of the zip file after it has been sent. Within days of
receipt of the delivery the PDS node acknowledges receipt of the archive and
checksum file. If acknowledgement is not received, or if problems are
reported, the MESSENGER SOC immediately takes corrective action to affect
successful transfer. Delivery size determines the transfer mechanism:
electronic or shipping a hard drive.
The PDS node uncompresses the zip archive file and checks for data integrity
using the checksum file. The node performs any additional verification and
validation of the data provided and reports any discrepancies or problems to
the MESSENGER SOC. The node performs these checks within about two weeks from
receipt of the delivery. After inspection has been completed to the
satisfaction of the PDS node, the node issues an acknowledgement of successful
receipt of the data to the MESSENGER SOC.
Following receipt of a data delivery the PDS node organizes the data into a
PDS volume archive structure within its online data system. Newly delivered
data are made available publicly from PDS once accompanying labels and other
documentation have been validated.
Labeling and Identification
The PDS label conforms to PDS version 3.8 standards. For more information
about this standard consult the PDS Standards Reference Document. The label is
detached and in a separate PDS label file. The purpose of the PDS label is to
describe the data product and provide ancillary information about the data
product. There is a PDS label file for every EPPS DDR data file. There is one
DATA_SET_ID assigned to the EPPS DDR data. The DDRs are further grouped into
data products and are identified by the STANDARD_DATA_PRODUCT_ID keyword and
the file naming convention, section 6.5. Example label file content is shown
here for every DDR data product. Note that the data are contained within an
ASCII table and the details of the table structure are described by an
external ASCII format file (*.FMT). The columns in each format file are
described separately in the Appendix.
EPS Pitch Angles Label
A sample EPS Pitch Angles DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 5798
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 167
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "EPSP_A2012010DDR_V1"
PRODUCT_VERSION_ID = "V1"
PRODUCT_CREATION_TIME = 2012-05-09T21:04:27
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "EPS_PITCH_ANGLES_DDR"
SOFTWARE_NAME = "MIDLMessengerDDRGenerator"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE SPECTROMETER"
INSTRUMENT_ID = "EPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-EPS-DDR-V1.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED EPS
DDR
V1.0"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2012-010T00:00:49
STOP_TIME = 2012-010T23:59:45
SPACECRAFT_CLOCK_START_COUNT = "234641115"
SPACECRAFT_CLOCK_STOP_COUNT = "234727451"
^HEADER = ("EPSP_A2012010DDR_V1.TAB", 1)
^ASCII_TABLE = ("EPSP_A2012010DDR_V1.TAB", 2)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 1
BYTES = 167
DESCRIPTION = "The first record of this
file is the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 7
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 167
ROWS = 5798
DESCRIPTION = "
This table contains Pitch Angles between the measured flow vector
direction and the magnetic field for each of the 6 sectors of
the MESSENGER EPS instrument. The complete column definitions are
contained in an external file found in the LABEL directory of the
archive volume. Additional details are contained in the DDR SIS
document."
NOTE = "Data Quality: 0"
^STRUCTURE = "EPS_PITCH_ANGLES.FMT"
END_OBJECT = ASCII_TABLE
END
EPS Select Pitch Angle Spectrogram Label
A sample EPS Select Pitch Angle Spectrogram DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
RECORD_TYPE = UNDEFINED
INTERCHANGE_FORMAT = BINARY
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "EPS_PAS_2012074205045_V1"
PRODUCT_VERSION_ID = "V1"
PRODUCT_CREATION_TIME = 2012-05-09T17:00:00
PRODUCT_TYPE = "BROWSE"
STANDARD_DATA_PRODUCT_ID = "EPS_PITCH_ANGLE_SPECTROGRAM_DDR"
SOFTWARE_NAME = "MIDLMessengerDDRGenerator"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE SPECTROMETER"
INSTRUMENT_ID = "EPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-EPS-DDR-V1.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED EPS
DDR V1.0"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2012-03-14T20:50:45
STOP_TIME = 2012-03-15T00:23:45
SPACECRAFT_CLOCK_START_COUNT = "240245710"
SPACECRAFT_CLOCK_STOP_COUNT = "240258490"
^DOCUMENT = "EPS_PAS_2012074205045_V1.PNG"
OBJECT = DOCUMENT
DOCUMENT_NAME = "EPS_PAS_2012074205045_V1"
DOCUMENT_FORMAT = PNG
DOCUMENT_TOPIC_TYPE = "BROWSE IMAGE"
INTERCHANGE_FORMAT = BINARY
PUBLICATION_DATE = 2012-05-09T17:00:00
SOURCE_PRODUCT_ID = {
"EPSL_R2012074EDR_V1.DAT",
"MAGSC_SCIAVG12075_01_V00.TAB",
"MAGSC_SCIAVG12074_01_V00.TAB",
"EPSL_R2012075EDR_V1.DAT"
}
LINES = 400
LINE_SAMPLES = 850
SAMPLE_TYPE = MSB_UNSIGNED_INTEGER
SAMPLE_BITS = 8
DESCRIPTION = "PNG file containing a spectrogram
representation of the summation of the shaped count rates in detectors 0-10
except detector 3. The counts are binned in time (120 s) and pitch angle (22.5
deg). Constant normalization factors and background subtractions (see SIS for
Table) have been applied to these rates."
END_OBJECT = DOCUMENT
END
EPS Daily Pitch Angle Spectrogram Plot Label
A sample EPS Daily Pitch Angle Spectrogram Plot DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
RECORD_TYPE = UNDEFINED
INTERCHANGE_FORMAT = BINARY
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "EPS_PASD_IMAGE_2014100_DDR_V01"
PRODUCT_VERSION_ID = "V1"
PRODUCT_CREATION_TIME = 2017-005T16:43:05
PRODUCT_TYPE = "BROWSE"
STANDARD_DATA_PRODUCT_ID = "EPS_PA_SPEC_DDR"
SOFTWARE_NAME = "MIDLMESSENGERDDRGENERATOR"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE AND PLASMA SPECTROMETER"
INSTRUMENT_ID = "EPPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-EPS-DDR-V1.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED EPS DDR V1.0"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2014-04-10T00:00:00
STOP_TIME = 2014-04-10T23:59:59
SPACECRAFT_CLOCK_START_COUNT = "2/039411999"
SPACECRAFT_CLOCK_STOP_COUNT = "2/039498398"
^DOCUMENT = "EPS_PASD_IMAGE_2014100_DDR_V01.PNG"
OBJECT = DOCUMENT
DOCUMENT_NAME = "EPS_PASD_IMAGE_2014100_DDR_V01"
DOCUMENT_FORMAT = PNG
DOCUMENT_TOPIC_TYPE = "BROWSE IMAGE"
INTERCHANGE_FORMAT = BINARY
PUBLICATION_DATE = 2017-01-09
SOURCE_PRODUCT_ID = {
"EPSL_R2014100EDR_V1.DAT",
"MAGSC_SCIAVG14100_01_V08.TAB",
"EPSL_R2014101EDR_V1.DAT"
}
LINES = 400
LINE_SAMPLES = 850
SAMPLE_TYPE = MSB_UNSIGNED_INTEGER
SAMPLE_BITS = 8
DESCRIPTION = "
PNG file containing a spectrogram representation of the summation
of the shaped count rates in detectors 0-10 except detector 3. The
counts are binned in time (120 s) and pitch angle (22.5 deg).
Constant normalization factors and background subtractions
(see SIS for Table) have been applied to these rates."
END_OBJECT = DOCUMENT
END
EPS Daily Pitch Angle Spectrogram Data Label
A sample EPS Daily Pitch Angle Spectrogram data DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
RECORD_TYPE = "FIXED_LENGTH"
RECORD_BYTES = 406
FILE_RECORDS = 720
PRODUCT_ID = "EPS_PASD_NUMERIC_2014100_DDR_V01"
PRODUCT_VERSION_ID = "1"
PRODUCT_CREATION_TIME = 2017-005T16:43:05
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "EPS_PASD_NUMERIC_DDR"
SOFTWARE_NAME = "EPSDAILYPITCHANGLEPDSCSVFILEWRITER"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE AND PLASMA SPECTROMETER"
INSTRUMENT_ID = "EPPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-EPS-DDR-V1.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED EPS DDR V1.0"
MISSION_PHASE_NAME = "MERCURY ORBIT YEAR 4"
TARGET_NAME = "MERCURY"
SOURCE_PRODUCT_ID = {
"EPSL_R2014100EDR_V1.DAT",
"MAGSC_SCIAVG14100_01_V08.TAB",
"EPSL_R2014101EDR_V1.DAT"
}
START_TIME = 2014-04-10T00:00:00
STOP_TIME = 2014-04-10T23:59:58
SPACECRAFT_CLOCK_START_COUNT = "2/039411999"
SPACECRAFT_CLOCK_STOP_COUNT = "2/039498398"
^HEADER = ("EPS_PASD_NUMERIC_2014100_DDR_V01.TAB", 1)
^ASCII_TABLE = ("EPS_PASD_NUMERIC_2014100_DDR_V01.TAB", 2)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 1
BYTES = 406
DESCRIPTION = "The first record of this file is the header
section. The header contains column headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 17
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 406
ROWS = 720
DESCRIPTION = "The table contains charged particle rate
data from the MESSENGER EPS instrument binned by Pitch Angle."
^STRUCTURE = "EPS_PASD_NUMERIC_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Pitch Angles Label (PCHANG)
A sample FIPS Pitch Angles DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 1350
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 2799
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_PCHANG_2012001_DDR_V01"
PRODUCT_VERSION_ID = "V1"
PRODUCT_CREATION_TIME = 2012-05-08T23:35:42
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_PCHANG_DDR"
SOFTWARE_NAME = "mfips_decode_pha.pro"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "FAST IMAGING PLASMA SPECTROMETER"
INSTRUMENT_ID = "FIPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED
FIPS DDR V2.0"
SOURCE_PRODUCT_ID = "FileByFile"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2012-01-01T00:00:00
STOP_TIME = 2012-01-01T23:59:59
SPACECRAFT_CLOCK_START_COUNT = "233863466"
SPACECRAFT_CLOCK_STOP_COUNT = "233949802"
^HEADER = ("FIPS_PCHANG_2012001_DDR_V01.TAB",
1)
^ASCII_TABLE = ("FIPS_PCHANG_2012001_DDR_V01.TAB",
4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 8397
DESCRIPTION = "The first 3 records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 3
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 2799
ROWS = 1350
DESCRIPTION = "
This table contains FIPS Flux-Pitch angle histograms."
^STRUCTURE = "FIPS_PCHANG_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
Energy-Resolved Pitch Angle Distributions (ERPCHANG) Label
A sample FIPS ERPCHANG DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 5
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 16218
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_ERPCHANG_2011174_V1"
PRODUCT_VERSION_ID = "1"
PRODUCT_CREATION_TIME = 2014-11-06T16:00:00
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_ERPCHANG"
SOFTWARE_NAME = "MFIPS_DDR_SAMPLE.PRO"
SOFTWARE_VERSION_ID = "0.1"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE AND PLASMA SPECTROMETER"
INSTRUMENT_ID = "EPPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED FIPS DDR
V2.0"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2011-06-23T10:45:40.419666
STOP_TIME = 2011-06-23T22:53:43.420605
SPACECRAFT_CLOCK_START_COUNT = "1/217313408.800"
SPACECRAFT_CLOCK_STOP_COUNT = "1/217357091.000"
^HEADER = ("FIPS_ERPCHANG_2011174_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_ERPCHANG_2011174_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 48654
DESCRIPTION = "The first four records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 7
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 16218
ROWS = 2
DESCRIPTION = "
This table contains 2 dimensional pitch angle histograms as
described in EPPS DDR SIS."
^STRUCTURE = "FIPS_ERPCHANG_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Energy Spectra Label
A sample FIPS Energy Spectra DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 1350
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 4824
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_ESPEC_2012001_DDR_V01"
PRODUCT_VERSION_ID = "V1"
PRODUCT_CREATION_TIME = 2012-05-08T23:35:41
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_ESPEC_DDR"
SOFTWARE_NAME = "mfips_decode_pha.pro"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "FAST IMAGING PLASMA SPECTROMETER"
INSTRUMENT_ID = "FIPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED
FIPS DDR V2.0"
SOURCE_PRODUCT_ID = "FileByFile"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2012-01-01T00:00:00
STOP_TIME = 2012-01-01T23:59:59
SPACECRAFT_CLOCK_START_COUNT = "233863466"
SPACECRAFT_CLOCK_STOP_COUNT = "233949802"
^HEADER = ("FIPS_ESPEC_2012001_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_ESPEC_2012001_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 19094472
DESCRIPTION = "The first 3 records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 7
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 4824
ROWS = 1350
DESCRIPTION = "
This table contains FIPS energy spectra for selected ion species."
^STRUCTURE = "FIPS_ESPEC_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Observed Density Label
A sample FIPS Observed Density DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 1350
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 216
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_NOBS_2012001_DDR_V01"
PRODUCT_VERSION_ID = "V1"
PRODUCT_CREATION_TIME = 2012-05-08T23:35:42
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_NOBS_DDR"
SOFTWARE_NAME = "mfips_decode_pha.pro"
SOFTWARE_VERSION_ID = "1.0"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "FAST IMAGING PLASMA SPECTROMETER"
INSTRUMENT_ID = "FIPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED
FIPS DDR V2.0"
SOURCE_PRODUCT_ID = "FileByFile"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2012-01-01T00:00:00
STOP_TIME = 2012-01-01T23:59:59
SPACECRAFT_CLOCK_START_COUNT = "233863466"
SPACECRAFT_CLOCK_STOP_COUNT = "233949802"
^HEADER = ("FIPS_NOBS_2012001_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_NOBS_2012001_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 648
DESCRIPTION = "The first 3 records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 20
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 216
ROWS = 1350
DESCRIPTION = "
This table contains FIPS differential energy intensities for selected ion
species."
^STRUCTURE = "FIPS_NOBS_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Arrival Direction Label (Retired Product)
A sample FIPS Arrival Direction DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 42
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 9158
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_ARRDIR_2012054_DDR_V01"
PRODUCT_VERSION_ID = "01"
PRODUCT_CREATION_TIME = 2013-06-04T21:22:22
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_ARRDIR_DDR"
SOFTWARE_NAME = "mfips_ddr_sample.pro"
SOFTWARE_VERSION_ID = "0.1"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "FAST IMAGING PLASMA SPECTROMETER"
INSTRUMENT_ID = "FIPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V1.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED FIPS DDR
V1.0"
SOURCE_PRODUCT_ID = "FileByFile"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
SPACECRAFT_CLOCK_START_COUNT = "1/238523075.000"
START_TIME = 2012-02-23T22:20:08.845
SPACECRAFT_CLOCK_STOP_COUNT = "1/238524872.000"
STOP_TIME = 2012-02-23T22:50:05.845
^HEADER = ("FIPS_ARRDIR_2012054_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_ARRDIR_2012054_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 9158
DESCRIPTION = "The first three records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 7
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 9158
ROWS = 39
DESCRIPTION = "
This table contains FIPS ion flux as a function of arrival
direction which have been accumulated in time enough to be
meaningfully interpreted."
^STRUCTURE = "FIPS_ARRDIR_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Angular Flux Map Label
A sample FIPS Angular Flux Map DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 5
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 9162
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_FLUXMAP_2011174_V1"
PRODUCT_VERSION_ID = "1"
PRODUCT_CREATION_TIME = 2014-11-06T16:00:00
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_FLUXMAP"
SOFTWARE_NAME = "MFIPS_DDR_SAMPLE.PRO"
SOFTWARE_VERSION_ID = "0.1"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE AND PLASMA SPECTROMETER"
INSTRUMENT_ID = "EPPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED FIPS DDR
V2.0"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
START_TIME = 2011-06-23T10:45:40.420458
STOP_TIME = 2011-06-23T22:53:43.420605
SPACECRAFT_CLOCK_START_COUNT = "1/217313408.800"
SPACECRAFT_CLOCK_STOP_COUNT = "1/217357091.000"
^HEADER = ("FIPS_FLUXMAP_2011174_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_FLUXMAP_2011174_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 27486
DESCRIPTION = "The first four records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 7
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 9162
ROWS = 2
DESCRIPTION = "
This table contains angular flux map data as
described in EPPS DDR SIS."
^STRUCTURE = "FIPS_FLUXMAP_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Kinetic Properties Label
A sample FIPS Kinetic Properties DDR file label is shown below:
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 42
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 176
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_NTP_2012054_DDR_V01"
PRODUCT_VERSION_ID = "01"
PRODUCT_CREATION_TIME = 2013-06-04T21:22:22
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_NTP_DDR"
SOFTWARE_NAME = "mfips_ddr_sample.pro"
SOFTWARE_VERSION_ID = "0.1"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "FAST IMAGING PLASMA SPECTROMETER"
INSTRUMENT_ID = "FIPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED FIPS DDR
V2.0"
SOURCE_PRODUCT_ID = "FileByFile"
MISSION_PHASE_NAME = "MERCURY ORBIT"
TARGET_NAME = "MERCURY"
SPACECRAFT_CLOCK_START_COUNT = "1/238523075.000"
START_TIME = 2012-02-23T22:20:08.845
SPACECRAFT_CLOCK_STOP_COUNT = "1/238524872.000"
STOP_TIME = 2012-02-23T22:50:05.845
^HEADER = ("FIPS_NTP_2012054_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_NTP_2012054_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 176
DESCRIPTION = "
This table contains FIPS ion number densities and temperatures,
as well as the pressure calculated from their product.
Quantities are calculated after sufficient time accumulation
to allow meaningful interpretation."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 13
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 176
ROWS = 39
DESCRIPTION = "
This table contains FIPS NTP values."
^STRUCTURE = "FIPS_NTP_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
FIPS Viewing Normalization Products Labels
FIPS Cartesian to MSO Coordinates Rotation Matrix (ROTMSO)
PDS_VERSION_ID = "PDS3"
/* ** FILE FORMAT ** */
FILE_RECORDS = 1303
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 195
/* ** GENERAL DATA DESCRIPTION PARAMETERS ** */
PRODUCT_ID = "FIPS_ROTMSO_2010001_DDR_V01"
PRODUCT_VERSION_ID = "01"
PRODUCT_CREATION_TIME = 2014-06-04T10:00:00
PRODUCT_TYPE = "DDR"
STANDARD_DATA_PRODUCT_ID = "FIPS_ROTMSO_DDR"
SOFTWARE_NAME = "MFIPS_DDR_SAMPLE.PRO"
SOFTWARE_VERSION_ID = "0.1"
INSTRUMENT_HOST_NAME = "MESSENGER"
INSTRUMENT_NAME = "ENERGETIC PARTICLE AND PLASMA SPECTROMETER"
INSTRUMENT_ID = "EPPS"
DATA_SET_ID = "MESS-E/V/H/SW-EPPS-3-FIPS-DDR-V2.0"
DATA_SET_NAME = "MESSENGER E/V/H/SW EPPS CALIBRATED FIPS DDR
V2.0"
MISSION_PHASE_NAME = "MERCURY 4 CRUISE"
TARGET_NAME = "MERCURY"
SPACECRAFT_CLOCK_START_COUNT = "1/170791497.000"
START_TIME = 2010-01-01T00:00:23.676
SPACECRAFT_CLOCK_STOP_COUNT = "1/170877732.000"
STOP_TIME = 2010-01-01T23:57:38.677
^HEADER = ("FIPS_ROTMSO_2010001_DDR_V01.TAB", 1)
^ASCII_TABLE = ("FIPS_ROTMSO_2010001_DDR_V01.TAB", 4)
OBJECT = HEADER
HEADER_TYPE = TEXT
INTERCHANGE_FORMAT = "ASCII"
RECORDS = 3
BYTES = 585
DESCRIPTION = "The first three records of this
file are the header section. The header contains column
headings to improve usability."
END_OBJECT = HEADER
OBJECT = ASCII_TABLE
COLUMNS = 5
INTERCHANGE_FORMAT = ASCII
ROW_BYTES = 195
ROWS = 1300
DESCRIPTION = "
This table contains rotation matrix from FIPS cartesian
to MSO for each energy scan."
^STRUCTURE = "FIPS_ROTMSO_DDR.FMT"
END_OBJECT = ASCII_TABLE
END
Standards Used in Generating Data Products
PDS Standards
The EPPS DDR data products are constructed according to the data object
concepts developed by the PDS. By adopting the PDS format, the data products
are consistent in content and organization with other planetary data
collections. In the PDS standard, the DDR data file is grouped into objects
with PDS labels describing the objects. Each DDR data product consists of two
files:
A data file containing an ASCII table object (the primary data), in fixed
field format. ASCII table objects are in either comma separated value (CSV)
format (EPS) or are whitespace delimited (FIPS). This makes the ASCII data
extremely easy to read by many commercial off-the-shelf programs. The one
exception is the EPS Pitch Angle Spectrogram, which is a binary PNG file.
A label file which serves as a high-level description of the parameters of
which correspond to the data file. The label file contains a pointer to an
external format file, which details the structure of the table object in the
data file.
Time Standards
One of the time fields in the FIPS table objects references the Mission
Elapsed Time (MET). This MET is the spacecraft time in integer seconds that is
transmitted to MESSENGER subsystems by the Integrated Electronics Module
(IEM). MET = 0 is on August 3, 2004, at 05:59:16 UTC (coordinated universal
time), which is 1000 seconds prior to the MESSENGER launch. Relativistic
effects and circumstances occurring during the mission would result in MET not
being a true account of seconds since launch. Following a planned spacecraft
clock reset in early 2013, partition numbers (1/, or 2/) were added to product
labels to disambiguate MET seconds after the spacecraft clock reset (if
partition number is not present, SPICE defaults to partition 1/). For these
reasons the MESSENGER spacecraft clock coefficients file is archived at the
PDS NAIF Node. This file is used in conjunction with the leap seconds kernel
file in order to calculate the conversion between MET and UTC.
The conversion is easily done through the use of SPICE kernels and the CHRONOS
Utility. CHRONOS is a utility included with the SPICE package that is
distributed by the PDS NAIF node. The SPICE kernels are files that contain the
information needed to perform the conversion. Two SPICE kernels are required.
One is the Leap Seconds Kernel (LSK) and the other is the MESSENGER Spacecraft
Clock Kernel (SCLK). The SCLK file is used by CHRONOS to convert between
spacecraft clock time and ephemeris time, while the LSK file is used to
convert from ephemeris time to UTC time. The CHRONOS utility is
self-documenting and the SPICE package itself contains full documentation on
each of the utilities (including CHRONOS) and how they are used.
EPPS DDR data is time-tagged with spacecraft event time (SCET) in the
following UTC format: CCYY-DDDTHH:MM:SS.sss. This format represents a
concatenation of the conventional date and time expressions with the two parts
separated by the letter T:
CC - century (00-99)
YY - year (00-99)
DDD - day of year (001-366)
T - date/time separator
HH - hour (00-23)
MM - minute (00-59)
SS - second (00-59)
sss - fractions of second (000-999)
Coordinate Systems
There are two coordinate systems in use in the EPPS DDR data products: 1) the
Mercury-centric Solar Orbital (MSO, defined in the MESSENGER SPICE Dynamic
Frames Kernel) used for spacecraft position vectors; and 2) the FIPS Spherical
coordinate system, used for FIPS incident angles since it represents natural
coordinates for the sensor. The latter is a spherical version of the FIPS
Cartesian coordinate system (FIPS_CART), which is defined in the MESSENGER
SPICE Frames Kernel. FIPS Spherical coordinates (FIPS_SPH) consist of a radius
(r), zenith angle (theta) and azimuthal angle (phi). The zenith angle is
defined as the angle between the vector and the z axis in the FIPS Cartesian
coordinate system. It ranges from 0 to 180 degrees. The azimuthal angle ranges
from 0 to 360 degrees and is defined as the angle between the vector and the x
axis in the FIPS Cartesian coordinate system. The radius is defined as usual
as the magnitude of the FIPS Cartesian vector.
Data Storage Conventions
The data are organized following PDS standards and stored on hard disk at the
MESSENGER SOC. The SOC transfers data to PDS as detailed in section 5.3.3.
After verification of the data transfer PDS provides public access to
MESSENGER science data products through its online data distribution system.
Data Validation
The EPPS DDR data archive volume set includes all data acquired during the
MESSENGER mission. The archive validation procedure described in this section
applies to data products generated during all post launch phases of the
mission. To be clear, there is one and only one documentation volume and one
and only one EPPS data archive volume created over the whole mission. Release
dates are stated in the schedule in section 7. Updates to the data volume
occurred according to the same schedule. Updates to the documentation volume
occurred according to this schedule and at the discretion of the EPPS team.
PDS standards recommend that all data included in the formal archive be
validated through a peer-review process. This process is designed to ensure
that both the data and documentation are of sufficient quality to be useful to
future generations of scientists. The process is presented as several steps,
most of which occur in the PDS peer review. This peer review is conducted
before any volumes are produced and released to PDS.
The peer review panel consists of members of the EPPS team, the PPI node of
PDS, and at least one outside scientist actively working in the field of
energetic particles research. The PDS personnel are responsible for validating
that the volumes are fully compliant with PDS standards. The instrument team
and outside reviewer(s) are responsible for verifying the content of the data
set, the completeness of the documentation, and the usability of the data in
its archive format.
The peer review validates the documentation and data archive volumes. First
the panel reviews this document and verifies that the volumes and DDRs
produced to this specification will be useful. The peer review also validates
the EPPS DDR data in a two step process. The first step consists of reviewing
a sample data set for compliance with the PDS standards. The sample data set
is delivered and reviewed in conjunction with delivery and review of this SIS
document. The second step is examination of the data to ensure usability and
completeness. The PDS personnel are responsible for validating that the DDR
data set is fully compliant with PDS standards. The instrument team and the
outside science reviewer(s) are responsible for verifying the content of the
data set, the completeness of the documentation, and the usability of the data
in its archive format.
Any deficiencies in the archive data or documentation volumes are recorded as
liens against the product by the review panel. The sample data set is created
using software provided by APL and the University of Michigan. Once the sample
data are validated, and all liens placed against the product or product
generation software are resolved, the same software will be used to generate
subsequent data products in an automated fashion.
During automated production, the data file content is spot checked by members
of the EPPS team. "Quick look" products generated by software provided by ACT
and the EPPS team are produced routinely and examined by members of the team.
In addition, the data are actively used by team members to perform their
analysis. Any discrepancies in the data noted during these activities will be
investigated. If the discrepancy is a data error, the response depends on the
source of the error. If the error is in the software producing the data
product, the error is corrected and the data affected is reproduced, replacing
the data file. If there is a correctable error in a data file, the file is
replaced. If an error in a data file is uncorrectable, the error is described
in the cumulative errata file included in the archive volume. The structure of
data files and labels will be spot checked by the PPI node for compliance with
PDS standards and this SIS.
Detailed Data Product Specification
Data Product Structure and Organization
The MESSENGER EPPS DDR data products are archived at the PDS PPI Node. The
automated production and release of DDRs lends itself to the regular release
schedule outlined in section 7. If errors are discovered the data are replaced
with corrected DDRs on the next scheduled delivery date.
Calibration tables and calibration procedures are required to properly analyze
DDRs. These ancillary data are archived at the PDS PPI Node as part of the
EPPS documentation volume. The documentation volume is referenced by all EPPS
data archive volumes. The documentation volume therefore includes the EPPS EDR
SIS, the EPPS CDR SIS, and the EPPS DDR SIS in addition to the calibration
tables, calibration procedures, and other documents applicable to the data
archive volumes. A first release of the EPPS documentation volume accompanied
the initial release of the EPPS EDR data archive. An update to the EPPS
documentation volume will accompany the initial release of the DDR data
archive. After the initial releases of the DDR level documentation there were
updates to the documentation volume to document data quality and as needed for
product and calibration updates.
Handling Errors
The possibility exists that errors may be introduced into the archive even
with validation procedures applied to the archive volumes. An ERRATA report
file is maintained to track and document all discovered uncorrectable errors
that may occur during the mission. Correctable errors, such as revised DDRs or
DDRs that were missing from a previous PDS delivery are provided at the next
scheduled PDS delivery or at the final delivery date (schedule in section 7).
PDS then replaces the outdated files with the revised DDR files in the data
directories of the archive volume. File revisions are also recorded in the
data product label keywords PRODUCT_VERSION_ID and PRODUCT_CREATION_TIME,
which can be used in addition to ERRATA.TXT to detect updates. The ERRATA
report file is archived in the ROOT directory of the EPPS DDR data volume.
Data Format Description
Data are stored in ASCII table format. A detached PDS label file provides a
detailed description of the structure of each table.
Label and Header Descriptions
The following are the keyword definitions for the detached PDS label file,
which accompanies the instrument data file. The detached PDS label file has
the same name as the data file it describes, except for the extension .LBL to
distinguish it as a label file.
PDS_VERSION_ID
Represents the version number of the PDS standards documents that is valid
when a data product label is created. PDS3 is used for the MESSENGER data
products.
FILE_RECORDS
Indicates the number of physical file records, including both label records
and data records.
RECORD_TYPE
Indicates the record format of a file. Note: In the PDS, when record_type is
used in a detached label file it always describes its corresponding detached
data file, not the label file itself. The use of record_type along with other
file-related data elements is fully described in the PDS Standards Reference.
RECORD_BYTES
Indicates the number of bytes in a physical file record, including record
terminators and separators. Note: In the PDS, the use of record_bytes, along
with other file-related data elements is fully described in the Standards
Reference.
PRODUCT_ID
Represents a permanent, unique identifier assigned to a data product by its
producer.
PRODUCT_CREATION_TIME
Defines the UTC system format time when a product was created.
PRODUCT_VERSION_ID
Identifies the version of an individual product within a data set.
Example: 1.0, 2.0, 3.0.
Product_version_id is incremented if a given DDR has to be regenerated and
sent to PDS to replace a previously submitted DDR.
PRODUCT_TYPE
Identifies the type or category of a product within a data set.
STANDARD_DATA_PRODUCT_ID
Used to link an EPPS DDR file to one of the 12 types of EPPS data products
defined within the EPPS DDR SIS.
SOFTWARE_NAME
Identifies the data processing software used to convert from CDR into DDR
products.
SOFTWARE_VERSION_ID
Indicates the version of the data processing software used to generate the DDR
products.
MD5_CHECKSUM
Used to verify the successful electronic transfer of the DDR from the SOC to
the PDS-PPI Node.
INSTRUMENT_HOST_NAME
The full name of the host on which an instrument is based. In this case it is
the MESSENGER spacecraft.
INSTRUMENT_NAME
Provides the full name of the instrument.
INSTRUMENT_ID
Provides an abbreviated name or acronym which identifies an instrument.
DATA_SET_ID
The data_set_id element is a unique alphanumeric identifier for a data set or
a data product. The data_set_id value for a given data set or product is
constructed according to flight project naming conventions. There is only one
data_set_id for the EPPS DDRs.
MISSION_PHASE_NAME
Provides the commonly used identifier of a mission phase.
TARGET_NAME
The target_name element identifies a target. The target may be a planet,
satellite, ring, region, feature, asteroid or comet.
START_TIME
Provides the date and time of the beginning of an event or observation
(whether it be a spacecraft, ground-based, or system event) in UTC system
format.
STOP_TIME
Provides the date and time of the end of an observation or event (whether it
be a spacecraft, ground-based, or system event) in UTC system format.
SPACECRAFT_CLOCK_START_COUNT
Provides the value of the spacecraft clock at the beginning of a time period
of interest.
SPACECRAFT_CLOCK_STOP_COUNT
Provides the value of the spacecraft clock at the end of a time period of
interest.
^TABLE
Pointer to the DDR file, which contains the data in ASCII table format. The
structure of the data file is defined in a referenced format file.
OBJECT
Specifies that the DDR is a PDS TABLE object. This object contains its own
elements, which are defined below. NOTE: the end of the object definition is
always marked with an END_OBJECT line.
COLUMNS
Identifies the number of columns (fields) in the table.
INTERCHANGE_FORMAT
This element specifies that the table is in ASCII format.
ROW_BYTES
Specifies the number of bytes for each row in the table.
ROWS
Identifies the number of rows (records) in the table.
^STRUCTURE
This is a pointer to the external file which provides the structure definition
for the table object.
The following describes the keywords used to describe the PDS Table Object.
These keywords are contained in the FORMAT (.FMT) files for each DDR data
product.
COLUMN_NUMBER
Identifies the location of the column within the larger data object (such as a
table). For tables consisting of rows (I= 1, N) and columns (j = 1, M) the
column_number is the j-th index of any row.
NAME
Indicates a literal value representing the common term used to identify an
element or object. NOTE: in the PDS data dictionary, name is restricted to 30
characters and must conform to PDS nomenclature standards.
BYTES
Specifies the number of bytes allocated for this particular column element.
DATA_TYPE
Specifies the internal representation and/or mathematical properties of the
value being stored in this column.
START_BYTE
Identifies the location of the first byte of the particular column, counting
from 1.
ITEMS
Defines the number of multiple, identical occurrences of a single object. Used
mainly in columns containing spectral or histogram data.
ITEM_BYTES
The size in bytes of individual items in a column. ITEMS * ITEM_BYTES should
equal the value in the BYTES column.
The format file contains the full text for describing each column of the
table. See Appendices for a listing of each field in the individual format
files.
File Naming Conventions
The file names developed for PDS data volumes are restricted to a maximum
36-character file name and a 3-character extension name with a period
separating the file and extension names.
The general form of the EPPS EPS file name for pitch angle data is
"EPSP_AyyyydddDDR_V#.TAB" where
EPS Instrument name
P_A Pitch Angle
yyyy Four digit year
ddd Three digit day of year
DDR CODMAC processing level
V# Version number
The general form of the EPPS EPS file name for pitch angle spectrograms is
"EPS_PAS_ yyyydddhhmmss_V#.PNG" where
EPS Instrument name
PAS Select Pitch Angle Spectrogram
PASD Daily Pitch Angle Spectrogram
yyyy Four digit year
ddd Three digit day of year
hhmmss Hour, minute, second
V# Version number
PNG Portable Network Graphics file extension
The date in the file name is the start time of the data contained in the file.
The general form of the EPPS FIPS file name for DDRs is
"FIPS_❮TYPE❯_yyyyddd_DDR_V#.TAB" where
FIPS Instrument name
❮TYPE❯ Refers to the type of data contained in the file. Possible values
are
ESPEC - Energy Spectra
NOBS - Observed Density
PCHANG - Pitch Angle
ERPCHANG - Energy-Resolved Pitch Angle
ARRDIR - Arrival Direction
FLUXMAP - Angular Flux Map
NTP - Kinetic Properties
ROTMSO - Viewing Normalization rotation matrix to MSO
yyyy Four digit year
ddd Three digit day of year
DDR CODMAC processing level
V# Version number
For all EPPS data, the initial version number is "V1" (EPS and FIPS_FOVPIX) or
"V01" (all other FIPS). The version number increments for each successive
version of the DDR product that is produced. A new version of the DDR product
may be produced as a result of an error in the product or as a result of
errors discovered in the product generation process.
For all EPPS data except the EPS Pitch Angle Spectrogram plots:
TAB the file extension is dependent on the file type
.TAB, EPS and FIPS Instrument Data in ASCII table
.LBL, Detached PDS label file
EPS Select and Daily Pitch Angle Spectrogram plots:
PNG Plots in Portable Network Graphics image format
Archive Volume and File Size
Two archive volumes are created to archive both the EPPS DDR data and the
documentation, which is needed to analyze the DDRs. The first volume is the
EPPS Documentation Volume, having volume ID MESSEPPS_DOC. This documentation
volume contains products related to the EPPS EDR, CDR, and DDR data archives
including:
All required PDS catalog files for the EDR, CDR, and DDR archives.
The EDR, CDR, and DDR SIS documents.
The Space Sciences Review (SSR) instrument paper once copyright permission is
obtained. This may not be included in the initial release for copyright
reasons.
The EPPS calibration report.
The EPPS calibration procedures document.
Calibration tables.
Other documents considered useful by the MESSENGER project or the EPPS team.
The data archive volume, designated the EPPS Data Archive Volume and having
volume ID MESSEPPS_DDR, contains the DDR data and required files for
conforming to PDS volume archive standards. This includes the index files,
AAREADME.TXT file, etc. The approximate data archive volume size is 11 GB.
Directory Structure and Contents for EPPS Documentation Volume
The following illustration shows the directory structure overview for the EPPS
documentation volume.
❮ROOT❯
______________________|_____________________
| | |
❮CALIBRATION❯ ❮DOCUMENT❯ ❮CATALOG❯
|
______________|_______________
| | |
❮EDR_SIS❯ ❮CDR_SIS❯ ❮DDR_SIS❯
Figure 4 Documentation Volume Structure
Directory Contents
❮ROOT❯ Directory
This is the top-level volume directory. The following are files contained in
the root directory.
AAREADME.TXT - General information file. Provides users with an overview of
the contents and organization of the associated volume, general instructions
for its use, and contact 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 are documented in this file.
❮CALIBRATION❯ Directory
This contains the calibration tables needed to analyze the EPPS CDR data. The
calibration tables are in ASCII format. Format files for the calibration
tables are also located here, as are the following files.
CALINFO.TXT - Brief description of the directory contents and naming
conventions.
EPPS_*_EDR2CDR.PDF: Describes the procedure used to convert EDRs to CDRs for
each instrument, (as indicated by the * text).
FIP*.TAB: The FIPS energy per charge tables.
❮CATALOG❯ Directory
This subdirectory contains the catalog object files for the entire volume. The
following files are included in the catalog subdirectory.
CATINFO.TXT: Identifies and describes the function of each file in the catalog
directory.
EPPS*DATASET.CAT: Describes the general content of the EDR data set for each
instrument (as indicated by the * text) and includes information about the
duration of the mission and the person or group responsible for producing the
data.
EPPS*DATASET_CDR.CAT: Describes the general content of the CDR data set for
each instrument (as indicated by the * text) and includes information about
the duration of the mission and the person or group responsible for producing
the data.
EPPS*DATASET_DDR.CAT: Describes the general content of the DDR data set for
each instrument (as indicated by the * text) and includes information about
the duration of the mission and the person or group responsible for producing
the data.
INSTRUMENT.CAT: Describes physical attributes of the EPPS instrument and
provides relevant references to published literature.
INSTHOST.CAT: Describes the MESSENGER spacecraft.
MISSION.CAT: Describes the scientific goals and objectives of the MESSENGER
program. It also identifies key people and institutions.
PERSON.CAT: Lists and provides contact information for the people involved in
the MESSENGER mission, including those involved with EPPS.
REF.CAT: Provides references to scientific papers and other publications of
interest to those using the data, both for EPPS and the mission as a whole.
❮ DOCUMENT ❯ Directory
This subdirectory contains the documentation that is needed in order to
understand and analyze the EDR, CDR, and DDR data volumes. The documents are
separated into individual subdirectories according to the document type. The
document types are not restricted to the four shown in the graphical depiction
of the directory structure. There are additional document types as needed to
categorize each document. The following file is included in the subdirectory.
DOCINFO.TXT: Identifies and describes the function of each file in the
DOCUMENT directory.
Directory Structure and Contents for EPPS Data Volume
❮ROOT❯
___________________________|____________________________________
| | | | |
❮DATA❯ ❮GEOMETRY❯ ❮INDEX❯ ❮LABEL❯ ❮BROWSE❯
|
__|___________________________________________________________________
| | | | | | | | | |
❮EPS_PITCH_ANGLES❯ | ❮FIPS_PCHANG❯ | ❮FIPS_NOBS❯ ❮FIPS_NTP❯ | | |
| | ❮FIPS_ESPEC❯ | | |
| ❮EPS_PITCH_ANGLES_SPECTROGRAM❯ ❮FIPS_ROTMSO❯ | |
| __________________________| |
| | | | |
| ❮FIPS_ERPCHANG❯ ❮FIPS_FLUXMAP❯ |
_|_______________ ___________________|
| | | |
❮2008❯ ❮2009❯ ❮2010❯ ... ❮EPS_PA_DAILY_SPECTROGRAM❯
|
___|___________
| | |
❮JAN❯ ❮FEB❯ ❮MAR❯
Figure 5 Data Volume Directory Structure
Directory Contents
❮ROOT❯ Directory
This is the top-level directory of a volume. The following are files contained
in the root directory.
AAREADME.TXT - General information file. Provides users with an overview of
the contents and organization of the associated volume, general instructions
for its use, and contact 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 are documented in this file. This includes
revised DDRs meant to replace DDRs in a previous PDS delivery.
❮DATA❯ Directory
This top level directory contains the subdirectories corresponding to the ten
data products (section 5.2) and supporting products. The directories are
further subdivided into YEAR and MONTH directories. The FIPS_FOVPIX directory
contains the Pixel Field Of View ancillary products.
❮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 all data products on the volume.
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 DDR index file is organized as a table: there is one entry for
each of the data files included in the EPPS data set; the columns contain
parameters that describe the observation and instrument and spacecraft
parameters. These parameters include state information, such as integration
time, spacecraft clock count, time of observation, and instrument modes.
INDEX.LBL - Detached PDS label for INDEX.TAB. It contains the INDEX_TABLE
object which identifies and describes the columns of the EPPS index table.
MD5.TAB - The MD5 checksum file that contains MD5 hash values for every file
in the volume.
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.
❮BROWSE❯ Directory
This subdirectory contains viewable browse image plots of the daily pitch
angle spectrogram products. They correspond one-to-one with data products in
the DATA/EPS_PA_DAILY_SPECTROGRAM directory in the archive volume.
Archive Release Schedule to PDS
The MESSENGER EPPS data and volume archives were transferred from the SOC to
the PDS PPI Node using the process detailed in section 5.3.3. The SPICE
kernels were transferred to the NAIF node. The transfer took place according
to the schedule in [2].
Appendices
EPS_PITCH_ANGLES.FMT Table Columns
The following are the columns as defined by the EPS_PITCH_ANGLES.FMT structure
file. This file defines the ASCII table containing the EPS pitch angle data.
The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
Table 3 EPS_ PITCH_ANGLES.FMT Columns
Length (bytes)
Data Type
Column Name
Summary (see full text for column description)
21
TIME
TIME
Spacecraft event time (UTC) for this data record.
22
ASCII_REAL
PITCH_ANGLE_S0
Pitch angle (degrees) for sector 0.
22
ASCII_ REAL
PITCH_ANGLE_S1
Pitch angle (degrees) for sector 1.
22
ASCII_ REAL
PITCH_ANGLE_S2
Pitch angle (degrees) for sector 2.
22
ASCII_ REAL
PITCH_ANGLE_S3
Pitch angle (degrees) for sector 3.
22
ASCII_ REAL
PITCH_ANGLE_S4
Pitch angle (degrees) for sector 4.
22
ASCII_ REAL
PITCH_ANGLE_S5
Pitch angle (degrees) for sector 5.
EPS_PASD_NUMERIC_DDR.FMT Table Columns
The following are the columns as defined by the EPS_PASD_NUMERIC_DDR.FMT
structure file. This file defines the ASCII table containing the EPS daily
pitch angle spectrogram data. The archive volume is optimized by defining the
table structure once and providing a reference to it in the PDS label file.
The columns are numbered according to their column order in the table. Data
Type refers to the PDS standards data type for a particular column in the
table.
Table 4 EPS_PASD_NUMERIC_DDR.FMT Table Columns
Length (bytes)
Data Type
Column Name
Summary (see full text for column description)
19
TIME
TIME
Spacecraft event time (UTC) for this data record.
23
ASCII_REAL
0.0-11.25 degrees
Flux in pitch angle bin: 0.0-11.25 degrees.
23
ASCII_REAL
11.25-22.5 degrees
Flux in pitch angle bin: 11.25-22.5 degrees.
23
ASCII_REAL
22.5-33.75 degrees
Flux in pitch angle bin: 22.5-33.75 degrees.
23
ASCII_REAL
33.75-45.0 degrees
Flux in pitch angle bin: 33.75-45.0 degrees.
23
ASCII_REAL
45.0-56.25 degrees
Flux in pitch angle bin: 45.0-56.25 degrees.
23
ASCII_REAL
56.25-67.5 degrees
Flux in pitch angle bin: 56.25-67.5 degrees.
23
ASCII_REAL
67.5-78.75 degrees
Flux in pitch angle bin: 67.5-78.75 degrees.
23
ASCII_REAL
78.75-90.0 degrees
Flux in pitch angle bin: 78.75-90.0 degrees.
23
ASCII_REAL
90.0-101.25 degrees
Flux in pitch angle bin: 90.0-101.25 degrees.
23
ASCII_REAL
101.25-112.5 degrees
Flux in pitch angle bin: 101.25-112.5 degrees.
23
ASCII_REAL
112.5-123.75 degrees
Flux in pitch angle bin: 112.5-123.75 degrees.
23
ASCII_REAL
123.75-135.0 degrees
Flux in pitch angle bin: 123.75-135.0 degrees.
23
ASCII_REAL
135.0-146.25 degrees
Flux in pitch angle bin: 135.0-146.25 degrees.
23
ASCII_REAL
146.25-157.5 degrees
Flux in pitch angle bin: 146.25-157.5 degrees.
23
ASCII_REAL
157.5-168.75 degrees
Flux in pitch angle bin: 157.5-168.75 degrees.
23
ASCII_REAL
168.75-180.0 degrees
Flux in pitch angle bin: 168.75-180.0 degrees.
FIPS_PCHANG_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_ PCHANG_DDR.FMT structure
file. This file defines the ASCII table containing the FIPS pitch angle data.
The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
The INDEX field values are unique for a given day and may be used to match
data in this file to that in the other FIPS DDR files for the same day. This
fact is used to avoid data duplication: Universal Time (UTC) and MESSENGER
positions are given only in the FIPS_NOBS_DDR file.
Table 5 FIPS_PCHANG_DDR.FMT
Length (bytes)
Data Type
Field Name
Summary (see full text for column description)
7
ASCII Integer
INDEX
Unique identifier for the current data sample.
14
ASCII Real
MET
Mission Elapsed Time in seconds.
554
ASCII Real
H_PA
H+ flux-pitch angle histogram. Pitch angle range = 0 - 180 inclusive, where 0
is parallel to magnetic field. Binsize is 5 degrees.
554
ASCII Real
HE2_PA
He2+ flux-pitch angle histogram. Pitch angle range = 0 - 180 inclusive, where
0 is parallel to magnetic field. Binsize is 5 degrees.
554
ASCII Real
HE_PA
He+ flux-pitch angle histogram. Pitch angle range = 0 - 180 inclusive, where 0
is parallel to magnetic field. Binsize is 5 degrees.
554
ASCII Real
NAGROUP_PA
Na+ group flux-pitch angle histogram. Pitch angle range = 0 - 180 inclusive,
where 0 is parallel to magnetic field. Binsize is 5 degrees.
554
ASCII Real
OGROUP_PA
O+ group flux-pitch angle histogram. Pitch angle range = 0 - 180 inclusive,
where 0 is parallel to magnetic field. Binsize is 5 degrees.
FIPS_ERPCHANG_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_ ERPCHANG_DDR.FMT
structure file. This file defines the ASCII table containing the FIPS
energy-resolved pitch angle data. The archive volume is optimized by defining
the table structure once and providing a reference to it in the PDS label
file. The columns are numbered according to their column order in the table.
Data Type refers to the PDS standards data type for a particular column in the
table.
The START_INDEX and STOP_INDEX field values are unique for a given day and may
be used to match data in this file to that in the other FIPS DDR files for the
same day. This fact is used to avoid data duplication: Universal Time (UTC)
and MESSENGER positions are given only in the FIPS_NOBS_DDR file.
Table 6 FIPS_ERPCHANG_DDR.FMT
Length (bytes)
Data Type
Field Name
Summary (see full text for column description)
14
ASCII Integer
START_INDEX
Unique identifier for the start of the current sample range.
14
ASCII Integer
STOP_INDEX
Unique identifier for the end of the current sample range.
14
ASCII Real
START_MET
Mission Elapsed Time in seconds at the beginning of the accumulation.
14
ASCII Real
STOP_MET
Mission Elapsed Time in seconds at the end of the accumulation.
16
CHARACTER
TIME_RESL
Time resolution label.
16
CHARACTER
ION
Ion group label.
1152
ASCII Real
ERPCHANG
2D matrix (Pitch angle, DSHV step). Pitch angle range: 0 - 180 inclusive
divided over 10 degree bins. Matrix is ordered by sequential 64 element pitch
angle vectors (elements 0-63 are pitch angle 0, DSHV steps 0 to 63; elements
64-127 are pitch angle 10, steps 0 to 63; and so on).
FIPS_ESPEC_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_ ESPEC _DDR.FMT structure
file. This file defines the ASCII table containing the FIPS energy spectra
data. The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
The INDEX field values are unique for a given day and may be used to match
data in this file to that in the other two FIPS DDR files for the same day.
This fact is used to avoid data duplication: Universal Time (UTC) and
MESSENGER positions are given only in the FIPS_NOBS_DDR file.
Table 7 FIPS_ ESPEC_DDR.FMT Columns
Length
(bytes)
Data Type
Field Name
Summary (see full text for column description)
7
ASCII Integer
INDEX
Unique identifier for the current data sample.
14
ASCII Real
MET
Mission Elapsed Time in seconds.
959
ASCII Real
H
H+ flux per e/q in 1/(cm2 s kV).
959
ASCII Real
HE2
He2+ flux per e/q in 1/(cm2 s kV).
959
ASCII Real
HE
He+ flux per e/q in 1/(cm2 s kV).
959
ASCII Real
NA_GROUP
Na+ group flux per e/q in 1/(cm2 s kV).
959
ASCII Real
O_GROUP
O+ group flux per e/q in 1/(cm2 s kV).
FIPS_NOBS_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_NOBS_DDR.FMT structure
file. This file defines the ASCII table containing the FIPS observed density
data. The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
The INDEX field values are unique for a given day and may be used to match
data in this file to that in the other two FIPS DDR files for the same day.
This fact is used to avoid data duplication: Universal Time (UTC) and
MESSENGER positions are given only this file.
Table 8 FIPS_NOBS_DDR.FMT Columns
Length
(bytes)
Data Type
Field Name
Summary (see full text for column description)
7
ASCII Integer
INDEX
Unique identifier for the current data sample.
14
ASCII Real
MET
Mission Elapsed Time in seconds.
7
ASCII Real
ACCUM
Accumulation time for the current data sample.
15
ASCII Real
YFR
Time at end of the accumulation in floating point year.
8
ASCII Real
DOYFR
Time at end of the accumulation in floating point day of year.
5
ASCII Integer
HOURS
Hour at the end of the accumulation.
7
ASCII Integer
MINUTES
Minute at the end of the accumulation.
7
ASCII Real
SECONDS
Second at the end of the accumulation.
10
ASCII Real
MSOX
MESSENGER X-coordinate in MSGR_MSO frame in km.
10
ASCII Real
MSOY
MESSENGER Y-coordinate in MSGR_MSO frame in km.
10
ASCII Real
MSOZ
MESSENGER Z-coordinate in MSGR_MSO frame in km.
6
ASCII Real
LAT
MESSENGER position in Mercury latitude in degrees.
6
ASCII Real
MLT
MESSENGER position in magnetic local time in hour fraction.
9
ASCII Real
ALT
MESSENGER altitude in km.
14
ASCII Real
H
H+ observed density in cm-3.
14
ASCII Real
HE2
He2+ observed density in cm-3.
14
ASCII Real
HE
He+ observed density in cm-3.
14
ASCII Real
NA
Na+ observed density in cm-3.
14
ASCII Real
O
O+ observed density in cm-3.
4
ASCII Integer
QUAL
Data quality flag (0=good, 1=bad).
FIPS_ARRDIR_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_ARRDIR_DDR.FMT structure
file. This file defines the ASCII table containing the FIPS arrival direction
data. The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
The START_INDEX and STOP_INDEX field values are unique for a given day and may
be used to match data in this file to that in the other FIPS DDR files for the
same day. For example, the START_INDEX corresponds to the INDEX for the first
line in the FIPS NOBS data used for this accumulation. The STOP_INDEX
corresponds to the last line. This fact is used to avoid data duplication:
Universal Time (UTC) and MESSENGER positions are given only this file.
Table 9 FIPS_ARRDIR_DDR.FMT Columns
Length
(bytes)
Data Type
Field Name
Summary (see full text for column description)
14
ASCII Integer
START_INDEX
Unique identifier for the start of the current sample range.
14
ASCII Integer
STOP_INDEX
Unique identifier for the end of the current sample range.
14
ASCII Real
START_MET
Mission Elapsed Time at the beginning of the accumulation.
14
ASCII Real
STOP_MET
Mission Elapsed Time at the end of the accumulation.
14
ASCII
TIME_RESL
String label for time resolution of current line.
14
ASCII
ION
Name of ion or ion group.
9072
ASCII Real
DIRECTIONAL_FLUX
Ion flux as a function of arrival direction. Units: (cm^2 s keV/keV sr)^-1.
FIPS_FLUXMAP_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_FLUXMAP_DDR.FMT structure
file. This file defines the ASCII table containing the FIPS arrival direction
data. The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
The START_INDEX and STOP_INDEX field values are unique for a given day and may
be used to match data in this file to that in the other FIPS DDR files for the
same day. For example, the START_INDEX corresponds to the INDEX for the first
line in the FIPS NOBS data used for this accumulation. The STOP_INDEX
corresponds to the last line. This fact is used to avoid data duplication:
Universal Time (UTC) and MESSENGER positions are given only this file.
Table 10 FIPS_FLUXMAP_DDR.FMT Columns
Length
(bytes)
Data Type
Field Name
Summary (see full text for column description)
14
ASCII Integer
START_INDEX
Unique identifier for the start of the current sample range.
14
ASCII Integer
STOP_INDEX
Unique identifier for the end of the current sample range.
14
ASCII Real
START_MET
Mission Elapsed Time at the beginning of the accumulation.
14
ASCII Real
STOP_MET
Mission Elapsed Time at the end of the accumulation.
14
ASCII
TIME_RESL
String label for time resolution of current line.
14
ASCII
ION
Name of ion or ion group.
9072
ASCII Real
DIRECTIONAL_FLUX
Ion flux as a function of arrival direction. Units: (cm^2 s keV/keV sr)^-1.
FIPS_NTP_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_NTP_DDR.FMT structure
file. This file defines the ASCII table containing the FIPS arrival direction
data. The archive volume is optimized by defining the table structure once and
providing a reference to it in the PDS label file. The columns are numbered
according to their column order in the table. Data Type refers to the PDS
standards data type for a particular column in the table.
The START_INDEX and STOP_INDEX field values are unique for a given day and may
be used to match data in this file to that in the other FIPS DDR files for the
same day. For example, the START_INDEX corresponds to the INDEX for the first
line in the FIPS NOBS data used for this accumulation. The STOP_INDEX
corresponds to the last line. This fact is used to avoid data duplication:
Universal Time (UTC) and MESSENGER positions are given only this file.
Table 11 FIPS_NTP_DDR.FMT Columns
Length
(bytes)
Data Type
Field Name
Summary (see full text for column description)
14
ASCII Integer
START_INDEX
Unique identifier for the start of the current sample range.
14
ASCII Integer
STOP_INDEX
Unique identifier for the end of the current sample range.
14
ASCII Real
START_MET
Mission Elapsed Time at the beginning of the accumulation.
14
ASCII Real
STOP_MET
Mission Elapsed Time at the end of the accumulation.
14
ASCII
TIME_RESL
String label for time resolution of current line.
14
ASCII
ION
Name of ion or ion group.
14
ASCII Real
N
Ion number density in units of cm^-3.
14
ASCII Real
T
Ion temperature in units of MK.
14
ASCII Real
P
Ion pressure in units of nPa.
14
ASCII Real
N_ERR
Error in ion number density in units of cm^-3.
14
ASCII Real
T_ERR
Error in ion temperature in units of MK.
14
ASCII Real
P_ERR
Error in ion pressure in units of nPa..
6
ASCII Integer
QUAL
Quality Flag. 0=Good; non-0=Bad. Non-zero flag values TBD.
FIPS_ROTMSO_DDR.FMT Table Columns
The following are the columns as defined by the FIPS_ROTMSO_DDR.FMT structure
file. This file defines the ASCII table containing the FIPS Cartesian to MSO
rotation matrix definition. The archive volume is optimized by defining the
table structure once and providing a reference to it in the PDS label file.
The columns are numbered according to their column order in the table. Data
Type refers to the PDS standards data type for a particular column in the
table.
The INDEX field values are unique for a given day and may be used to match
data in this file to that in the other two FIPS DDR files for the same day.
This fact is used to avoid data duplication: Universal Time (UTC) and
MESSENGER positions are given only this file.
Table 12 FIPS_ROTMSO_DDR.FMT Columns
Length
(bytes)
Data Type
Field Name
Summary (see full text for column description)
11
ASCII Integer
INDEX
Unique identifier for the current data sample.
20
ASCII Real
MET
Mission Elapsed Time at the end of the corresponding FIPS scan.
54
ASCII Real
MATRIX_ROW_0
FIPS FOV to MSGR MSO rotation matrix row 0.
54
ASCII Real
MATRIX_ROW_1
FIPS FOV to MSGR MSO rotation matrix row 1.
54
ASCII Real
MATRIX_ROW_2
FIPS FOV to MSGR MSO rotation matrix row 2.
SPICE Kernel Files Used in MESSENGER Data Products
The following SPICE kernel files were used to compute the UTC time and any
geometric quantities found in the PDS labels. Kernel files were generated
throughout the mission with a file naming convention specified by the
MESSENGER project.
*.bsp:
MESSENGER spacecraft ephemeris file. Also known as the Planetary Spacecraft
Ephemeris Kernel (SPK) file.
*.bc:
MESSENGER spacecraft orientation file. Also known as the Attitude C-Kernel
(CK) file.
*.tf:
MESSENGER reference frame file. Also known as the Frames Kernel. Contains the
MESSENGER spacecraft, science instrument, and communications antennae frame
definitions.
*.ti:
MESSENGER instrument kernel (I-kernel). Contains references to mounting
alignment, operation modes, and timing as well as internal and field of view
geometry for the EPPS.
*.tsc:
MESSENGER spacecraft clock coefficients file. Also known as the Spacecraft
Clock Kernel (SCLK) file.
*.tpc:
Planetary constants file. Also known as the Planetary Constants Kernel (PcK)
file.
*.tls:
NAIF leapseconds kernel file. Used in conjunction with the SCLK kernel to
convert between Universal Time Coordinated (UTC) and MESSENGER Mission Elapsed
Time (MET). Also called the Leap Seconds Kernel (LSK) file.
CODMAC/NASA Definition of Processing Levels
CODMAC/NASA Definition of processing levels for science data sets
CODMAC Level
Proc. Type
Data Processing Level Description
1
Raw Data
Telemetry data stream as received at the ground station, with science and
engineering data embedded. Corresponds to NASA packet data.
2
Edited Data
Instrument science data (e.g. raw voltages, counts) at full resolution, time
ordered, with duplicates and transmission errors removed. Referred to in the
MESSENGER program as Experiment Data Records (EDRs). Corresponds to NASA Level
0 data.
3
Calibrated Data
Edited data that are still in units produced by instrument, but have
transformed (e.g. calibrated, rearranged) in a reversible manner and packaged
with needed ancillary and auxiliary data (e.g. radiances with calibration
equations applied). Referred to in the MESSENGER Program as Calibrated Data
Records (CDRs). In some cases these also qualify as derived data products
(DDRs). Corresponds to NASA Level 1A.
4
Resampled data
Irreversibly transformed (e.g. resampled, remapped, calibrated) values of the
instrument measurements (e.g. radiances, magnetic field strength). Referred to
in the MESSENGER program as either derived data products (DDPs) or derived
analysis products (DAPs). Corresponds to NASA Level 1B.
5
Derived Data
Derived results such as maps, reports, graphics, etc.
Corresponds to NASA Levels 2 through 5
6
Ancillary Data
Non-Science data needed to generate calibrated or resampled data sets.
Consists of instrument gains, offsets; pointing information for scan
platforms, etc.
7
Corrective Data
Other science data needed to interpret space-borne data sets. May include
ground based data observations such as soil type or ocean buoy measurements of
wind drift.
8
User Description
Description of why the data were required, any peculiarities associated with
the data sets, and enough documentation to allow secondary user to extract
information from the data.
The above is based on the national research council committee on data
management and computation (CODMAC) data levels.
MESSENGER Glossary and Acronym List
ACT Applied Coherent Technology Corporation
AMU Atomic Mass Unit
APL The Johns Hopkins University Applied Physics Laboratory
ASCII American Standard Code for Information Interchange
CDR Calibrated Data Record
CK Attitude C-Kernel (SPICE)
CODMAC Committee on Data Management and Computation
DAP Derived Analysis Products
DDP Derived Data Products
EDR Experiment Data Records
EPPS Energetic Particle and Plasma Spectrometer
EPS Energetic Particle Spectrometer
ESA Electrostatic Analyzer
FIFO First In, First out. An electronic component that stores and
retrieves
information following a first-in-first-out discipline.
FIPS Fast Imaging Plasma Spectrometer
FOV Field-of-View
FSW Flight Software
FTP File Transfer protocol
GEANT4 GEometry ANd Tracking software toolkit
GF Geometric Factor
I2C Inter-Integrated Circuit
JPL Jet Propulsion Laboratory
IEM Integrated Electronic Module
LSB Least Significant Bit
LSK Leapseconds Kernel (SPICE)
MCP Micro-channel Plate
MESSENGER MErcury Surface, Space ENvironment, GEochemistry, and Ranging
MET Mission Elapsed Time
MIDL Mission Independent Data Layer
MSO Mercury-centric Solar Orbital
NAIF Navigation and Ancillary Information Facility
NASA National Aeronautics and Space Administration
PCK Planetary Constant Kernel (SPICE)
PDS Planetary Data System
PHA Pulse Height Analysis
PPI Planetary Plasma Interactions PDS Node
RDR Reduced Data Record
SCLK Space Clock Kernel (SPICE)
SOC Science Operations Center
SPICE Spacecraft, Planet, Instrument, C-matrix Events, refers to the kernel
files and NAIF software used to generate viewing geometry.
SPK Spacecraft and Planets Kernel (SPICE)
SSD Solid-State Detector
SSR Space Sciences Review
TOF Time of Flight
UTC Coordinated Universal Time
[SE1]Should this be "browse" to be consistent with earlier part of sentence or
"image"?
[SE2]image or browse?
[SE3]image or browse?
EPPS DDR SIS 02/10/17
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