PDS_VERSION_ID = PDS3
LABEL_REVISION_NOTE = "
For New Horizons, this LABEL_REVISION_NOTE is used to keep track of
when the template is used to generate a DATASET.CAT file for a
data set.
- Publication date: 2017-04-30
- NH-internal archive software version: V2.0
2017-12-01: The dataset delivered in 2017 includes updates to TARGET_NAME
values as well as updated calibrations based on a spacecraft
Calibration Campaign conducted in 2016.
"
RECORD_TYPE = STREAM
INSTRUMENT_HOST_NAME = "NEW HORIZONS"
OBJECT = DATA_SET
DATA_SET_ID = "NH-P-SWAP-2-PLUTO-V3.0"
OBJECT = DATA_SET_INFORMATION
START_TIME = 2015-01-14T18:08:02.690
STOP_TIME = 2016-10-29T18:08:01.356
DATA_SET_DESC = "
Data Set Overview
=================
This data set contains Raw data taken by New Horizons
Solar Wind Around Pluto
instrument during the PLUTO mission phase.
SWAP comprises electro-optics and detectors to obtain count rate
measurements of the solar wind; measuring the solar wind before,
during and after the Pluto encounter will allow characterization
of the atmospheric escape rate of Pluto. The SWAP electro-optic
elements select the angles and energies of the solar wind and
pickup ions to be measured; ions thus selected are registered with
a coincidence detector system. SWAP measures the energy spectrum
of ions in its environment by varying (also called scanning or
sweeping) voltages of the electro-optics over many steps during a
short time period. SWAP can also immediately follow a sweep of
coarse voltage steps with a sweep of finer steps, centered on the
peak measurement of the coarse sweep, to obtain a higher
resolution of that portion of the energy spectrum.
There are three types of SWAP science data: real-time; summary;
histogram. Real-time data, at rates up to 1Hz, provide the most
detailed science measurements since they contain the full count
rate distribution as a function of energy (speed). For science
summary and science histogram modes, the full distribution is not
recorded. Instead, parameters are derived from the count rate
distribution stored by SWAP. These derived parameters require less
memory than storing the whole distribution. The science summary
and science histogram modes are primarily used during the cruise
phase of the mission. For science data, the common data product is
usually a binary table; for calibrated real-time data,
spectrograms as images are also provided. Typically the tables
have instrument parameters and measurements in the columns and
measurement times in the rows, but the actual format depends on
the type of data and the processing level (raw vs. calibrated).
Other tables containing housekeeping and other parameters are also
provided. This data set includes documentation for all data types
and formats.
During the Pluto Charon Encounter mission phase starting in January,
2015, there were several sub-phases: three Approach sub-phases, (AP1,
AP2 and AP3); a CORE sequence for the Pluto flyby on 14.July, 2015 (Day
Of Year 195), sometimes also referred to as NEP (Near-Encounter Phase);
three Departure sub-phases (DP1, DP2, DP3); a Transition sub-phase
closing out the mission phase in October, 2016. For this final SWAP
delivery for the Pluto mission phase, this data set includes all data
for the Pluto Encounter mission phase, downlinked through late
October, 2016.
SWAP was turned on for nominal operations throughout approach, other
than powering off and on around trajectory correction maneuvers. It was
operating as a ridealong during the PEPSSI plasmarolls, on DOY 107,
115, 121, 128, 148, 156, and 176. There were two other dedicated SWAP
and PEPSSI rolls on DOY 163 and 171. SWAP gain functional testing
occurred on DOY 016 and 137.
Note: Sub-phases AP1, AP2 and AP3 started on 2015-01-15, 2015-04-05
and 2015-06-23, respectively. Sub-phases DP1, DP2 and DP3
started on 2015-07-16, 2015-08-04 and 2015-10-22, respectively.
Every observation provided in this data set was taken as a part of a
particular sequence. A list of these sequences has been provided in
file DOCUMENT/SEQ_SWAP_PLUTO.TAB.
N.B. Some sequences provided may have no corresponding observations.
For a list of observations, refer to the data set index table. This
is typically INDEX.TAB initially in the INDEX/ area of the data set.
There is also a file SLIMINDX.TAB in INDEX/ that summarizes key
information relevant to each observation, including which sequence
was in effect and what target was likely intended for the
observation.
Version
=======
This is VERSION 3.0 of this data set.
General statement about data set versions after V1.0
----------------------------------------------------
The pipeline (see Processing below) was re-run on these data for each
version since the first (V1.0). That will typically change only the
FITS headers but not the FITS data of raw data sets. In some cases
this may change the calibration because the calculated geometry of an
observation has changed. See data set version-specific sections below
for significant exceptions to this general statement, i.e. changes to
pipeline processing, calibration processing, and data delivered.
An all-instrument Calibration Campaign occurred in July 2016. For all
instruments, calibrations were updated as of April 2017 which changed
the data in the calibrated data sets. Calibration changes are described
in the data set version-specific sections.
Note that even if this is not a calibrated data set, calibration
changes are listed as the data will have been re-run and there will be
updates to the calibration files, to the documentation (Science
Operations Center - Instrument Interface Control Document:
SOC_INST_ICD) and to the steps required to calibrate the data.
SWAP updates for Pluto Encounter
Data Sets V3.0
==============
This P3 Pluto Encounter dataset release includes all data from the
previous two Pluto deliveries and adds data that was downlinked from
1/31/2016 through 10/31/2016. This dataset completes delivery of all
data covering the Pluto Encounter and subsequent Calibration Campaign.
For SWAP, most of the Pluto Encounter data was downlinked in the 15229
load in August 2015. Since then, SWAP has stayed on and taken data
continuously, other than a few power cycles around spacecraft events
such as 3-Axis operations and trajectory correction maneuvers.
Downlink data several days beyond the end of the nominal end of
mission phase were included in this data set in an attempt to fill out
the products at the nominal end of mission phase; refer to the
CONFIDENCE_LEVEL_NOTE in this data set catalog for more details.
There have been several changes to the PDS data labels, mostly
involving improved values for the NAME, AXIS_NAME, and DESCRIPTION
keywords in ARRAY OBJECTs in SWAP Histogram products. As part of
that work, the count rate HISTOGRAM has been converted to an ARRAY
object to take advantage of the improvements.
SWAP updates for Pluto Encounter
Data Sets V2.0
==============
This P2 Pluto Encounter dataset release provides updates to the
Pluto dataset between P1 (data on the ground by 7/31/2015) and P2
(data on the ground by 1/31/2016). All liens from the initial
Pluto delivery have also now been resolved. For SWAP, most of the
Pluto Encounter data was downlinked in the 15229 load in August
2015. Since then, SWAP has stayed on and taken data continuously,
other than a few power cycles around spacecraft events such as
3-Axis operations and trajectory correction maneuvers.
Processing
==========
The data in this data set were created by a software data
processing pipeline on the Science Operations Center (SOC) at
the Southwest Research Institute (SwRI), Department of Space Operations.
This SOC pipeline assembled data as FITS files from raw telemetry
packets sent down by the spacecraft and populated the data labels
with housekeeping and engineering values, and computed geometry
parameters using SPICE kernels. The pipeline did not resample
the data.
Data
====
The observations in this data set are stored in data files using
standard Flexible Image Transport System (FITS) format. Each FITS
file has a corresponding detached PDS label file, named according
to a common convention. The FITS files may have image and/or table
extensions. See the PDS label plus the DOCUMENT files for a
description of these extensions and their contents.
This Data section comprises the following sub-topics:
- Filename/Product IDs
- Instrument description
- Other sources of information useful in interpreting these Data
- Visit Description, Visit Number, and Target in the Data Labels
Filename/Product IDs
--------------------
The filenames and product IDs of observations adhere to a
common convention e.g.
SWA_0123456789_0X584_ENG.FIT
^^^ ^^^^^^^^^^ ^^^^^ ^^^\__/
| | | | ^^
| | | | |
| | | | +--File type (includes dot)
| | | | - .FIT for FITS file
| | | | - .LBL for PDS label
| | | | - not part of product ID
| | | |
| | | +--ENG for CODMAC Level 2 data
| | | SCI for CODMAC Level 3 data
| | |
| | +--Application ID (ApID) of the telemetry data
| | packet from which the data come
| | N.B. ApIDs are case-insensitive
| |
| +--MET (Mission Event Time) i.e. Spacecraft Clock
|
+--Instrument designator
Note that, depending on the observation, the MET in the data filename
and in the Product ID may be similar to the Mission Event Time (MET)
of the actual observation acquisition, but should not be used as an
analog for the acquisition time. The MET is the time that the data are
transferred from the instrument to spacecraft memory and is therefore
not a reliable indicator of the actual observation time. The PDS label
and the index tables are better sources to use for the actual timing of
any observation. The specific keywords and index table column names for
which to look are
* START_TIME
* STOP_TIME
* SPACECRAFT_CLOCK_START_COUNT
* SPACECRAFT_CLOCK_STOP_COUNT
Instrument Instrument designators ApIDs **
=========== ================================== =============
SWAP SWA 0X584 - 0X587 *
* Not all values in this range are in this data set
** ApIDs are case insensitive
There are other ApIDs that contain housekeeping values and
other values. See SOC Instrument ICD (/DOCUMENT/SOC_INST_ICD.*)
for more details.
Here is a summary of the types of files generated by each ApID
(N.B. ApIDs are case-insensitive) along with the instrument
designator that go with each ApID:
ApIDs Data product description/Prefix(es)
===== ===================================
0x584 - SWAP Science Real-Time/SWA
0x585 - SWAP Science Summary/SWA *
0x586 - SWAP Science Histogram Header/SWA
0x587 - SWAP Science Histogram Data/SWA
* Level 3 NH SWAP data sets produced after April, 2016 do not have
0x585 (Science Summary data); in-flight and in practice, 0x585
data are used only for health and safety and not for science.
Instrument description
----------------------
Refer to the following files for a description of this instrument.
CATALOG
SWAP.CAT
DOCUMENTS
SWAP_SSR.*
SOC_INST_ICD.*
NH_SWAP_V###_TI.TXT (### is a version number)
Other sources of information useful in interpreting these Data
--------------------------------------------------------------
Refer to the following files for more information about these data
NH Trajectory tables:
/DOCUMENT/NH_MISSION_TRAJECTORY.* - Heliocentric
SWAP Field Of View definitions:
/DOCUMENT/NH_FOV.*
/DOCUMENT/NH_SWAP_V###_TI.TXT
SWAP Data summary plots:
/DOCUMENT/DATA_SUMMARY_PLOTS/SWAP_###DAY_YYYYMMDDHH_#.*
Visit Description, Visit Number, and Target in the Data Labels
---------------------------------------------------------------
The observation sequences were defined in Science Activity Planning
(SAP) documents, and grouped by Visit Description and Visit Number.
The SAPs are spreadsheets with one Visit Description & Number per row.
A nominal target is also included on each row and included in the data
labels, but does not always match with the TARGET_NAME field's value in
the data labels. In some cases, the target was designated as RA,DEC
pointing values in the form ``RADEC=123.45,-12.34'' indicating Right
Ascension and Declination, in degrees, of the target from the
spacecraft in the Earth Equatorial J2000 inertial reference frame.
This indicates either that the target was either a star, or that the
target's ephemeris was not loaded into the spacecraft's attitude and
control system which in turn meant the spacecraft could not be pointed
at the target by a body identifier and an inertial pointing value had
to be specified as Right Ascension and Declination values. PDS-SBN
practices do not allow putting a value like RADEC=... in the PDS
TARGET_NAME keyword's value. In those cases the PDS TARGET_NAME value
is set to CALIBRATION. TARGET_NAME may be N/A (Not Available or Not
Applicable) for a few observations in this data set; typically that
means the observation is a functional test so N/A is an appropriate
entry for those targets, but the PDS user should also check the
NEWHORIZONS:OBSERVATION_DESC and NEWHORIZONS:SEQUENCE_ID keywords in
the PDS label, plus the provided sequence list (see Ancillary Data
below) to assess the possibility that there was an intended target.
These two keywords are especially useful for STAR targets as often
stars are used as part of instrument calibrations, and are
included as part of the sequencing description which is captured
in these keywords.
Ancillary Data
==============
The geometry items included in the data labels were computed
using the SPICE kernels archived in the New Horizons SPICE
data set, NH-X-SPICE-6-PLUTO-V1.0.
Every observation provided in this data set was taken as a part of a
particular sequence. A list of these sequences has been provided in
file DOCUMENT/SEQ_SWAP_PLUTO.TAB. In addition, the
sequence identifier (ID) and description are included in the PDS label
for every observation. N.B. While every observation has an associated
sequence, every sequence may not have associated observations. Some
sequences may have failed to execute due to spacecraft events (e.g.
safing). No attempt has been made during the preparation of this data
set to identify such empty sequences, so it is up to the user to
compare the times of the sequences to the times of the available
observations from INDEX/INDEX.TAB to identify such sequences.
Time
====
There are several time systems, or units, in use in this dataset:
New Horizons spacecraft MET (Mission Event Time or Mission Elapsed
Time), UTC (Coordinated Universal Time), and TDB Barycentric
Dynamical Time.
This section will give a summary description of the relationship
between these time systems. For a complete explanation of these
time systems the reader is referred to the documentation
distributed with the Navigation and Ancillary Information
Facility (NAIF) SPICE toolkit from the PDS NAIF node, (see
http://naif.jpl.nasa.gov/).
The most common time unit associated with the data is the spacecraft
MET. MET is a 32-bit counter on the New Horizons spacecraft that
runs at a rate of about one increment per second starting from a
value of zero at
19.January, 2006 18:08:02 UTC
or
JD2453755.256337 TDB.
The leapsecond adjustment (DELTA_ET = ET - UTC) was 65.184s at
NH launch, and the first three additional leapseconds occurred
in at the ends of December, 2009, June, 2012 and June, 2015.
Refer to the NH SPICE data set, NH-J/P/SS-SPICE-6-V1.0, and the
SPICE toolkit documentation, for more details about leapseconds.
The data labels for any given product in this dataset usually
contain at least one pair of common UTC and MET representations
of the time at the middle of the observation. Other portions
of the products, for example tables of data taken over periods
of up to a day or more, will only have the MET time associated
with a given row of the table.
For the data user's use in interpreting these times, a reasonable
approximation (+/- 1s) of the conversion between Julian Day (TDB)
and MET is as follows:
JD TDB = 2453755.256337 + ( MET / 86399.9998693 )
For more accurate calculations the reader is referred to the
NAIF/SPICE documentation as mentioned above.
Reference Frame
===============
Geometric Parameter Reference Frame
-----------------------------------
Earth Mean Equator and Vernal Equinox of J2000 (EMEJ2000) is the
inertial reference frame used to specify observational geometry items
provided in the data labels. Geometric parameters are based on best
available SPICE data at time of data creation.
Epoch of Geometric Parameters
-----------------------------
All geometric parameters provided in the data labels were computed at
the epoch midway between the START_TIME and STOP_TIME label fields.
Software
========
The observations in this data set are in standard FITS format
with PDS labels, and can be viewed by a number of PDS-provided
and commercial programs. For this reason no special software is
provided with this data set.
Contact Information
===================
For any questions regarding the data format of the archive,
contact
New Horizons SWAP Principal Investigator:
David McComas, Princeton University
David McComas
Princeton University
Princeton Plasma Physics Laboratory
Peyton Hall
Princeton, NJ 08544
USA
"
CONFIDENCE_LEVEL_NOTE = "
Confidence Level Overview
=========================
During the processing of the data in preparation for
delivery with this volume, the packet data associated with each
observation were used only if they passed a rigorous verification
process including standard checksums.
In addition, raw (Level 2) observation data for which adequate
contemporary housekeeping and other ancillary data are not available
may not be reduced to calibrated (Level 3) data. This issue is raised
here to explain why some data products in the raw data set,
NH-P-SWAP-2-PLUTO-V3.0,
may not have corresponding data products in the calibrated data set,
NH-P-SWAP-3-PLUTO-V3.0.
Data coverage and quality
=========================
Every observation provided in this data set was taken as a part of a
particular sequence. A list of these sequences has been provided in
file DOCUMENT/SEQ_SWAP_PLUTO.TAB. N.B. Some sequences
provided may have zero corresponding observations.
Refer to the Confidence Level Overview section above for a summary
of steps taken to assure data quality.
SWAP data product completeness at the end of a mission phase
------------------------------------------------------------
Downlink data several days beyond the end of the nominal end of
mission phase* were included in this data set in an attempt to fill
the products at the nominal end of mission phase*. This was done in
an attempt to ensure complete coverage of data up through the nominal
end of the mission phase*. This also means that for the SWAP
last-in-time products in this data set, which include observations
beyond the nominal end of the mission phase*, may be incomplete.
The following paragraphs provide details about this issue.
SWAP data product completeness - details
----------------------------------------
SWAP data are taken more or less continuously, but telemetry downlinks
are done in batches, so the SWAP data are stored on-board the
spacecraft at least until they are downlinked, sometimes hours or days
after they are taken. Furthermore, SWAP PDS data are grouped into
products, each covering approximately one day's worth of data,
starting and ending at a time of day near 18:08 UTC.
This data set comprises data downlinked through a fixed cutoff date*.
The interaction between the downlink cutoff, the batch nature of
downlink, and the grouping of SWAP data will result in the last day's,
or few days', data products in this data set containing less than
a full day's worth of data. This applies to SWAP science and
engineering data as well as housekeeping and thruster data stored in
the data products. This has been most noticeable during the Pluto
PDS data set deliveries, e.g. the last product in the V2.0 delivery
with ApID 0x585 had very little science data and neither housekeeping
nor thruster data, whereas the same product in the V3.0 delivery had
the full expected day's worth of data; also, the V3.0 delivery has a
product with ApID 0x584 that was not present in the V2.0 delivery.
The NH project is considering delivering SWAP data sets as a single
incrementing data set. Beyond that and other than adding a few days
of telemetry beyond the nominal mission phase end*, the NH project has
no further plans to mitigate this minor issue.
In summary, the choice to deliver New Horizon data sets by mission
phase affects SWAP data set product completeness near those mission
phase boundaries.
* Refer to the DATA_SET_DESC or ABSTRACT_DESC of this data set catalog
for the actual final downlink date, and to the mission catalog for
the nominal mission phase boundaries.
Observation descriptions in this data set catalog
=================================================
Some users will expect to find descriptions of the observations
in this data set here, in this Confidence Level Note. This data
set follows the more common convention of placing those
descriptions under the Data Set Description (above, if the user is
reading this in the DATASET.CAT file) of this data set catalog.
Caveat about TARGET_NAME in PDS labels and observational intent
===============================================================
The downlink team on New Horizons has
created an automated system to take various uplink products, decode
things like Chebyshev polynomials in command sequences representing
celestial body ephemerides for use on the spacecraft to control
pointing, and infer from those data what the most likely intended
target was at any time during the mission. This works well during
flyby encounters and less so during cruise phases and hibernation.
The user of these PDS data needs to
be cautious when using the TARGET_NAME and other target-related
parameters stored in this data set. This is less an issue for the
plasma and particle instruments, more so for pointing instruments.
To this end, the heliocentric ephemeris of the spacecraft, the
spacecraft-relative ephemeris of the inferred target, and the
inertial attitude of the instrument reference frame are provided
with all data, in the J2000 inertial reference frame, so the user
can check where that target is in the Field Of View (FOV) of the
instrument.
Finally, note that, within the FITS headers of the data products,
the sequence tables, and other NH Project-internal documents used
in this data set and/or inserted into the data set catalog,
informal names are often used for targets instead of the canonical
names required for the TARGET_NAME keyword. For example, during
the Pluto mission phase, instead of the TARGET_NAME '15810 ARAWN
(1994 JR1)' there might be found any of the following: 1994JR1;
1994 JR1; JR1. For all values where the PDS keyword TARGET_NAME
is used (e.g. in PDS labels and in index tables), the canonical,
PDS-approved names are used (if not, please bring this to the
attention of PDS so it can be rectified). However, within the
context of this data set, these project abbreviations are not
ambiguous (e.g. there is only one NH target with 'JR1' in its
name), so there has been, and will be, no attempt to expand such
abbreviations where they occur outside formal PDS keyword values.
Review
======
This dataset was peer reviewed and certified for scientific use on
June 19, 2017.
"
ABSTRACT_DESC = "
This data set contains Raw data taken by the New Horizons
Solar Wind Around Pluto
instrument during the
Pluto encounter
mission phase. This is VERSION 3.0 of this data set.
This data set contains SWAP observations taken during the
the Approach (Jan-Jul, 2015), Encounter, Departure, and
Transition mission sub-phases, including flyby observations
taken on 14 July, 2015, and departure and calibration data
through late October, 2016. This data set completes the
Pluto mission phase deliveries for SWAP.
This is version 3.0 of this dataset. Changes since version 2.0 include
the addition of data downlinked between the end of January, 2016 and
the end of October, 2016, completing the delivery of all data covering
the Pluto Encounter and subsequent Calibration Campaign.
Also, updates were made to the calibration files, documentation, and
catalog files. Finally, downlink data several days beyond the end of
the nominal end of mission phase were included in this data set in an
attempt to fill out the products at the nominal end of mission phase;
refer to the CONFIDENCE_LEVEL_NOTE in this data set catalog for more
details.
"
CITATION_DESC = "
McComas, D., NEW HORIZONS
Raw SWAP PLUTO ENCOUNTER V3.0,
NH-P-SWAP-2-PLUTO-V3.0,
NASA Planetary Data System, 2018.
"
DATA_OBJECT_TYPE = TABLE
DATA_SET_COLLECTION_MEMBER_FLG = "N"
DATA_SET_NAME = "NEW HORIZONS
SWAP PLUTO ENCOUNTER
RAW V3.0"
DATA_SET_RELEASE_DATE = 2017-04-30
DATA_SET_TERSE_DESC = "
Raw data taken by New Horizons
Solar Wind Around Pluto
instrument during the PLUTO mission phase.
This is VERSION 3.0 of this data set.
"
DETAILED_CATALOG_FLAG = "N"
PRODUCER_FULL_NAME = "TIFFANY FINLEY"
END_OBJECT = DATA_SET_INFORMATION
OBJECT = DATA_SET_MISSION
MISSION_NAME = "NEW HORIZONS"
END_OBJECT = DATA_SET_MISSION
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "N/A"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
OBJECT = DATA_SET_TARGET
TARGET_NAME = "SOLAR WIND"
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_HOST
INSTRUMENT_HOST_ID = "NH"
INSTRUMENT_ID = "SWAP"
END_OBJECT = DATA_SET_HOST
END_OBJECT = DATA_SET
END
|