| DATA_SET_DESCRIPTION |
Data Set Overview
=================
This data set contains Raw data taken by New Horizons
Linear Etalon Imaging Spectral Array
instrument during the PLUTO mission phase.
LEISA is an infrared imaging spectrometer. The two-dimensional (2-D)
detector is a 256x256-pixel array. Spectral separation is done with a
wedged optical etalon filter, which comprises high (2.1-2.25 micron) and
low (1.25-2.5 micron) spectral resolution segments. The optics and
filter arrangement configure one detector dimension as spatial at
constant wavelength and the other dimension as both spectral and
spatial. Multiple frames (images) may be taken in sequence, while
scanning the Field Of View (FOV) in the spatial+spectral dimension, such
that each pixel-sized piece of the observed target will be observed at
all wavelengths across multiple frames. The resulting data products in
this data set are three-dimensional image cubes, which dimensions are
spatial, spatial+spectral, and spatial+time and which shall be convolved
into spatial, spatial, and spectral image cubes at a later date.
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 around 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 Pluto Encounter mission phase ending in late
October, 2016.*. For this final Ralph-LEISA delivery for this
Pluto-Charon Encounter mission phase, this data set includes all
Approach, CORE, Departure, and Transition data downlinked through the
end of October, 2016.
* Mission phase definitions are 'soft'; refer to the mission catalog
NH.CAT for explanations of phase designation.
The time of the closest approach to Pluto (PCA) by the New Horizons
spacecraft was 14-JUL-2015 11:48:28.771 UTC +/- 0.6s, based on the
NAIF/SPICE New Horizons PDS data set [NH-J/P/SS-SPICE-6.V1.0]. Data
products around this time will be found in the following directories
(if present): 20150714_0299916; 20150714_0299917; 20150714_0299918;
20150714_0299919.
On Approach during April, May and June of 2015, LEISA operations
included the following: functional testsincluding a scan test; and
observations of Pluto, Charon and the other Plutonian satellites.
This dataset includes the first 3 P-LEISA scans of Pluto taken at 28,
26, and 24 days before the Pluto closest approach, to look for changes
in surface color and composition over multiple rotations. It also
includes three of the PC_VISUV_MAP observations at 18, 17, and 15 days
before encounter, with the same goal as P-LEISA. At 13 days,
PC_LEISA_VAR looks at the IR variability of Pluto and Charon.
The dataset also has a series of PC_MULTI_MAP observations, from 11
days and 2 days before closest approach. The PC_MULTI_MAPs met
multiple objectives as measurements coordinated with the P-Alice,
LORRI, and MVIC instruments. For LEISA, these objectives included
determining Pluto and Charon phase integrals, as LEISA offers another
alternative to visible wavelength imaging to get the angular
dependence of scattering by Pluto. They also are the primary method of
performing global temperature mapping of Pluto's surface ices, based
on LEISA near-IR spectral-imaging. The measurements support further
goals for IR spectroscopic maps of Pluto and Charon, searching for
changes over multiple rotations, looking at the composition of low
albedo areas of Pluto, and investigating the composition of
non-encounter hemispheres of Pluto and Charon. Also, using LEISA to
observe various regions of Pluto at or near the approach and departure
asymptote phase angles supports the determination of the bolometric
albedos of various regions. Finally, LEISA spectral studies of Pluto
at multiple phase angles helps to learn about surface processing and
structure in various regions.
This LEISA dataset also has 2 observations on the day of closest
approach: (1) P_LEISA_Alice_1a, which is a backup for scans of whole
disk at 7-10 km/pix to get a global infrared spectral map of Pluto;
and (2) C_LEISA_LORRI_1, which gives the Charon resolved IR surface
map and phase integral, and spectral studies of Charon at multiple
phase angles to learn about surface processing and structure in
various regions. Both also fulfill the objectives of the MULTI_MAPs.
This final delivery also has the remainder of the encounter multi-maps
and other Pluto system observations, including full-frame versions
of images for which only windows were downlinked in past deliveries.
From the Transition sequence there are functional tests and star
calibrations, taken in mid-2016.
Note that the smaller satellites of Pluto, Kerberos and Styx, were not
directly observed by LEISA. Although there may be observations with
those smaller satellites in the background, identifying such
observations is beyond the scope of this delivery; the user is
referred to the NAIF/SPICE data set [NH-J/P/SS-SPICE-6-V1.0] to
calculate the location of any objects possibly within the fields of
view of any observations.
Note that, in many Pluto data sets, there will be windowed products
(see the LEISA.CAT instrument catalog file for more detail about
windows), but the targeted object may or may not be visible in the
downlinked window in any given frame.
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_LEISA_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.
The TARGET_NAME values were expanded and made more consistent across
all instruments with version 3.0 of the 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.
LEISA 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.
It includes the additional observations below for LEISA:
Request ID|Obs. Start Time (S/C UTC)|Downlink Complete (GRT)|Obs. Target
PELE_01_PC_Multi_Map_A_18 2015-188_16:46:57 2016-095T01:02:52 Pluto and Charon
PELE_01_PC_Multi_Map_B_2 2015-189_09:06:50 2016-282T19:11:23 Pluto and Charon
PELE_01_PC_Multi_Map_B_3 2015-189_17:08:54 2016-090T19:59:19 Pluto and Charon
PELE_01_PC_Multi_Map_B_5 2015-190_03:42:44 2016-299T09:48:47 Pluto and Charon
PELE_01_PC_Multi_Map_B_6 2015-190_16:58:09 2016-088T16:40:25 Pluto and Charon
PELE_01_PC_Multi_Map_B_8 2015-191_08:57:34 2016-076T18:59:15 Pluto and Charon
PELE_01_PC_Multi_Map_B_9 2015-191_16:57:39 2016-167T17:50:32 Pluto and Charon
PELE_02_PC_Multi_Map_B_9 2015-191_17:16:09 2016-083T17:54:02 Pluto and Charon
PELE_01_PC_Multi_Map_B_11 2015-192_03:37:31 2016-289T23:58:48 Pluto and Charon
PELE_01_PC_Multi_Map_B_12 2015-192_16:53:46 2016-279T03:25:46 Pluto and Charon
PELE_02_PC_Multi_Map_B_12 2015-192_17:16:16 2016-290T00:05:48 Pluto and Charon
PELE_01_PC_Multi_Map_B_14 2015-193_08:25:59 2016-115T15:57:41 Pluto and Charon
PELE_01_PC_Multi_Map_B_15 2015-193_16:56:55 2016-137T10:37:29 Pluto and Charon
PELE_01_PC_Multi_Map_B_17 2015-194_03:41:29 2016-105T03:34:59 Pluto and Charon
PELE_01_PC_Multi_Map_B_18 2015-194_07:42:17 2016-200T12:24:15 Pluto and Charon
PELE_01_PCNH_Multi_Long_1d1 2015-194_14:53:36 2016-086T01:46:57 P,C, Nix,
Hydra
PELE_01_PC_Multi_Long_1d2 2015-194_21:11:03 2016-247T04:35:45 Pluto and Charon
PELE_01_P_Leisa 2015-195_01:54:07 2016-126T06:11:48 Pluto
PELE_01_C_Leisa 2015-195_02:17:23 2016-114T18:12:01 Charon
PELE_01_U_TBD_2 2015-195_04:23:26 2016-112T03:48:13 Kerberos or Styx
PELE_01_H_Leisa_backup 2015-195_04:42:10 2016-155T00:29:42 Hydra
PELE_01_H_Leisa_Best 2015-195_07:22:47 2016-108T20:24:04 Hydra
PELE_01_N_Leisa_backup 2015-195_07:52:41 2016-167T15:31:26 Nix
PELE_01_C_LEISA_LORRI_1 2015-195_09:15:16 2016-076T06:34:15 Charon
PELE_01_N_LEISA_LORRI 2015-195_09:58:10 2016-152T14:09:24 Nix
PELE_01_P_Multi_Dep_Long_1 2015-195_15:22:23 2016-058T05:37:58 Pluto
PELE_01_PC_Multi_Dep_Long_2 2015-195_19:12:38 2016-137T12:54:34 Pluto, Charon
PELE_02_PC_Multi_Dep_Long_2 2015-195_19:23:49 2016-140T09:00:18 Pluto, Charon
PELE_02_PC_Multi_Dep_Long_3 2015-196_03:10:23 2016-125T22:19:49 Pluto, Charon
PELE_01_PC_Multi_Dep_Long_3 2015-196_03:17:41 2016-141T11:30:48 Pluto, Charon
PELE_01_PC_Ralph_Charon_270deg 2015-197_18:42:33 2016-150T05:07:41 Pluto,
Charon
PELE_01_PC_Ralph_N2_Bright 2015-198_07:47:12 2016-140T07:59:51 Pluto, Charon
PELE_01_PC_Ralph_Pluto_CO 2015-199_07:43:28 2016-160T04:06:03 Pluto, Charon
PELE_01_PC_Ralph_Enc_Hem_Dep 2015-199_15:45:29 2016-160T07:45:53 Pluto, Charon
PELE_01_PC_Ralph_Dark_Area 2015-200_07:43:28 2016-160T03:53:43 Pluto, Charon
PELE_01_PC_Ralph_Charon_90Deg 2015-200_23:42:27 2016-151T04:49:13 Pluto,
Charon
TRRL_X_RALPH_FUNCLITEA_182__021aFunc 2016-182_01:34:56 2016-182T13:35:20 Cal
TRRL_X_RALPH_FUNCLITEA_182__021aFuncRaw 2016-182_01:36:54 2016-184T09:26:38
Cal
TRRL_X_RALPH_FUNCLITEB_182__021bFunc 2016-182_02:09:56 2016-182T15:55:44 Cal
TRRL_X_RALPH_FUNCLITEB_182__021bFuncRaw 2016-182_02:11:54 2016-182T16:44:17
Cal
TRLE_Arcturus_048_CAL_01_197 2016-197_08:54:21 2016-208T16:37:58 Calibration
TRLE_Arcturus_048_CAL_02_197 2016-197_09:04:21 2016-208T14:28:16 Calibration
TRLE_Arcturus_048_CAL_03_197 2016-197_09:14:21 2016-211T08:42:01 Calibration
TRLE_Arcturus_048_CAL_04_197 2016-197_09:24:21 2016-215T15:26:23 Calibration
TRLE_Arcturus_048_CAL_05_197 2016-197_09:34:21 2016-215T16:17:00 Calibration
TRLE_Arcturus_048_CAL_06_197 2016-197_09:44:21 2016-224T16:52:11 Calibration
TRLE_Arcturus_048_CAL_01_197_Yaw 2016-197_09:59:23 2016-232T15:19:32
Calibration
TRLE_Arcturus_048_CAL_02_197_Yaw 2016-197_10:09:23 2016-244T13:23:00
Calibration
TRLE_Arcturus_048_CAL_03_197_Yaw 2016-197_10:19:23 2016-242T05:58:48
Calibration
TRLE_Arcturus_048_CAL_04_197_Yaw 2016-197_10:29:23 2016-251T11:07:36
Calibration
TRLE_Arcturus_048_CAL_01_A_197 2016-197_10:53:21 2016-234T08:00:12 Calibration
TRLE_049_SIACAL_01_198 2016-198_10:17:43 2016-227T14:52:42 Calibration
TRLE_049_SIACAL_02_198 2016-198_10:29:43 2016-228T05:45:17 Calibration
Updates were made to the calibration files, documentation, and
catalog files. The data were re-run through the pipeline, which would
change the FITS headers of the raw files, but not the FITS data. The
exceptions to that would be products for which only sub-frame windows
were downlinked in previous versions of this data set: those products
have been re-downlinked either in full, or all regions outside the
previously downloaded windows were downloaded and merged to form
full-frame products. In so doing, some LEISA products will have
more frames downloaded, resulting in a change in the BANDS keyword
value in PDS labels. Finally, the updated calibration files will
change all of the calibrated data.
As of V3.0, targets for some stars and radio sources have been updated
so that the TARGET_NAME keyword in the label is accurate and more
descriptive than only STAR or CALIBRATION. However the user should
confirm that targets from the data FITS files, if applicable for a
given instrument, match the label name, as there are a few instances
where the FITS keywords for TARGET, SPCCBTNM, and PNTMTHD are not
accurate. The simplest way to check is to instead look at the RA
and Dec in the keywords SPCBRRA and SPCBRDEC in the FITS file.
This issue mostly only occurs with star targets.
LEISA 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. The dataset includes the additional
observations below which are all from the Pluto Encounter timeframe:
Obs. Name (Request ID), Obs Date, Downlink Start, Downlink End, Obs. Target
PELE_01_C_LEISA_Hires 2015-07-14 2015/276 2015/276 Charon observations
PELE_01_C_LEISA_LORRI_1 2015-07-14 2015/325 2015/325 Charon observations
PELE_01_PC_Multi_Map_A_3 2015-07-02 2015/229 2015/229 Pluto, Charon
observations
PELE_01_P_LEISAFlat_1 2015-07-14 2015/253 2015/253 Pluto observations
PELE_01_P_LEISAFlat_2 2015-07-14 2015/253 2015/253 Pluto observations
PELE_01_P_LEISA_Alice_1a 2015-07-14 2015/200 2016/009 Pluto observations
PELE_01_P_LEISA_Alice_1b 2015-07-14 2015/352 2015/352 Pluto observations
PELE_01_P_LEISA_Alice_2a 2015-07-14 2015/289 2015/289 Pluto observations
PELE_01_P_LEISA_Alice_2b 2015-07-14 2015/263 2015/263 Pluto observations
PELE_01_P_Multi_Dep_Long_1 2015-07-14 2016/009 2016/009 Pluto observations
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.
LSB_0123456789_0X53C_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 **
=========== ================================== =============
LEISA LSB, LRW 0X53C - 0X54E *
* 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 meanings of each instrument designator:
Instr
Dsgn. Description
===== ===========
LSB LEISA, Read minus Reset data
LRW LEISA, Raw Read and Reset data
See SOC Instrument ICD (/DOCUMENT/SOC_INST_ICD.*) for 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)
===== ===================================
0x53c - LEISA Lossless (CDH 1)/LRW,LSB
0x54b - LEISA Lossless (CDH 2)/LRW,LSB
0x53d - LEISA Packetized (CDH 1)/LRW,LSB
0x54c - LEISA Packetized (CDH 2)/LRW,LSB
0x53e - LEISA Lossy (CDH 1)/LRW,LSB
0x54d - LEISA Lossy (CDH 2)/LRW,LSB
Instrument description
----------------------
Refer to the following files for a description of this instrument.
CATALOG
LEISA.CAT
DOCUMENTS
RALPH_SSR.*
SOC_INST_ICD.*
NH_RALPH_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
RALPH Field Of View definitions:
/DOCUMENT/NH_FOV.*
/DOCUMENT/NH_RALPH_V###_TI.TXT
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_LEISA_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 RALPH Principal Investigator:
Alan Stern, Southwest Research Institute
S. Alan Stern
Southwest Research Institute (SwRI)
Department of Space Studies
1050 Walnut Street, Suite 400
Boulder, CO 80302
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-LEISA-2-PLUTO-V3.0,
may not have corresponding data products in the calibrated data set,
NH-P-LEISA-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_LEISA_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.
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.
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