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. Brian Carcich - Publication date: 2016-04-22 - NH-internal archive software version: V2.0 " RECORD_TYPE = STREAM INSTRUMENT_HOST_NAME = "NEW HORIZONS" OBJECT = DATA_SET DATA_SET_ID = "NH-P-LEISA-2-PLUTO-V1.0" OBJECT = DATA_SET_INFORMATION START_TIME = 2015-03-03T12:35:00.739 STOP_TIME = 2015-07-14T09:24:26.876 DATA_SET_DESC = " 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 (1.225-2.5 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 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). For this first Ralph-LEISA delivery for the Pluto mission phase, this data set includes only the Approach data plus the subset of the CORE sequence data that was downlinked through the end of July, 2015. The rest of the Pluto data will be delivered in future versions of this data set according to the schedule worked out by the Project and NASA. 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. The remainder of the LEISA dataset 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. 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 1.0 of this data set. Processing ========== The data in this data set were created by a software data processing pipeline on the Science Operation Center (SOC) at the Southwest Research Institute (SwRI), Department of Space Studies. 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 | | | +--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 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 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. The PDS standards 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. 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; that is, some sequences may have failed to execute due to spacecraft events (e.g. safing) and there will be observations associated with those sequences. No attempt has been made during the preparation of this data set to identify if any, or how many, such empty sequences there are, so it is up to the user to compare the times of the sequences to the times of the available observations from the INDEX/INDEX.TAB table 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) over this dataset is 65.184s. 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 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-V1.0, may not have corresponding data products in the calibrated data set, NH-P-LEISA-3-PLUTO-V1.0. Data coverage and quality ========================= Caveat about TARGET_NAME in PDS labels and observational intent =============================================================== A fundamental truth of managing data from some spacecraft missions is that the intent of any observation is not suitable for insertion into the command stream sent to the spacecraft to execute that observation. As a result, re-attaching that intent to the data that are later downlinked is problematic at best. For New Horizons that task is made even more difficult as the only meta-data that come down with the observation is the unpredictable time of the observation. The task is made yet even more difficult because uplink personnel, who generate the command sequences and initially know the intent of each observation, are perpetually under deadlines imposed by orbital mechanics and can rarely be spared for the time-intensive task of resolving this issue. To make a long story short, 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 point to be made is that 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. Furthermore, for pointing instruments with one or more spatial components to their detectors, a table has been provided in the DOCUMENT/ area with XY (two-dimensional) positions of each inferred target in the primary data products. If those values are several thousand pixels off of a detector array, it is a strong indication that the actual target of that observation is something other than the inferred target, or no target at all e.g. dark sky. Review ====== This dataset was peer reviewed and certified for scientific use on TBD. " ABSTRACT_DESC = " This data set contains Raw data taken by the New Horizons Linear Etalon Imaging Spectral Array instrument during the Pluto encounter mission phase. This is VERSION 1.0 of this data set. " CITATION_DESC = " Stern, A., NEW HORIZONS Raw LEISA PLUTO ENCOUNTER V1.0, NH-P-LEISA-2-PLUTO-V1.0, NASA Planetary Data System, 2016. " DATA_OBJECT_TYPE = "IMAGE" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_SET_NAME = "NEW HORIZONS LEISA PLUTO ENCOUNTER RAW V1.0" DATA_SET_RELEASE_DATE = 2016-04-22 DATA_SET_TERSE_DESC = " Raw data taken by New Horizons Linear Etalon Imaging Spectral Array instrument during the PLUTO mission phase. This is VERSION 1.0 of this data set. " DETAILED_CATALOG_FLAG = "N" PRODUCER_FULL_NAME = "JOSEPH PETERSON" 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 = "CHARON" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "PLUTO" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "VEGA" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = "NH" INSTRUMENT_ID = "LEISA" END_OBJECT = DATA_SET_HOST END_OBJECT = DATA_SET END