NSSDCA ID: PSSB-00742
Availability: Archived at NSSDC, accessible from elsewhere
This description was generated automatically using input from the Planetary Data System.
Data Set Overview ================= This data set contains Raw data taken by New Horizons Long Range Reconnaissance Imager instrument during the PLUTOCRUISE mission phase. LORRI is a narrow angle (Field Of View, FOV = 0.29 degree square), high resolution (5 microradian/pixel), telescope. A two-dimensional (2-D) CCD detector, with 1024x1024 pixels (optically active region) operates in standard frame-transfer mode. LORRI can also perform on-chip 4x4 binning to produce images of 256x256 pixels. LORRI has no color filters and so provides panchromatic imaging over a wide bandpass extending approximately from 350 nm to 850 nm. The common data product is a 2-D image of brightnesses that can be calibrated to physical units once color spectrum information is known. Refer to DOCUMENT/SOC_INST_ICD.* for more detail. LORRI Observation summary ========================= The spacecraft was in hibernation for much of the Pluto Cruise mission phase, and the focus for LORRI during Annual CheckOuts one through eight (ACO1-8) was preparation for the Pluto Encounter in 2015, including functional tests, calibrations, and encounter rehearsals in 2012 and 2013. Science observations performed by LORRI during this phase included the following targets: KBO objects KBO 2005 FY9 and KBO 2003 EL61; Centaur object Chariklo; the planets Neptune and Jupiter. The ACO tests also had LORRI observing several other targets: Pluto; Charon; star fields that will be visible during approach optical navigation activities (OPNAVs) and 3d before Pluto closest approach in 2015; the M7 star field; the stars Vega and Arcturus; the open cluster NGC 3532. A full functional test was performed during ACO1 in 2007, with ACO 'Lite' tests performed during ACO2-8 in 2008 through 2014. Specific tests and calibrations performed during ACOs included the following: scattered/stray light tests (2007, 2008, 2010, 2014); Pluto OpNav test (2007, 2008, 2014); lamp test (2007); star tracker calibration test (2008); GNC mosaic setting test (2008); LEISA-LORRI ridealong (2008); dither test (2010); 4x4 PSF test (2013); U_Hazard simulations (2013; 2014; Note 1). In 2013 during ACO-7, an observation was made to detect Charon. In 2014 during ACO-8, Pluto/Charon OPNAVs observations included a detection of Hydra. Note 1: U_Hazard observations were taken during the approach to Pluto encounter to determine if any hazards existed on the flight path through the Pluto system. 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_LORRI_PLUTOCRUISE.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 2.0 of this data set. The pipeline (see Processing below) was re-run on these data for each version since the first (V1.0). As a result, ancillary information, such as observational geometry and time (SPICE), may be updated. This will affect, for example, the calibration of the data if parameters such as the velocity or orientation of the target relative to the instrument, or the recorded target itself, have changed. See the following sections for details of what has changed over each version since the first (V1.0). Note that even if this is not a calibrated data set, the 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. LORRI updates for PLUTOCRUISE Data Sets V2.0 ============== The previous delivery (V1.0) went through peer review with many Pluto Cruise data sets in December, 2014. When subsequent versions of the latter were being delivered with additional data (from August, 2015 through January, 2016) before all of those liens were resolved, those data sets were left as is, with those liens folded into the newer data sets. The same path was chosen for this data set. No new observations were added with this new LORRI V2.0 data set. The changes for this version were re-running of the ancillary data in the data product, updated geometry from newer SPICE kernels, minor editing of the documentation, catalogs, etc., and resolution of liens from the December, 2014 review, plus those from the May, 2016 review of the Pluto Encounter data sets. The lossy images from Version 1.0 were recalibrated, including expanding the 'bad' pixel designation of 8x8 boxes affected by the first 34 pixels of header information in the calibrated quality map. 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. The first 34 pixels (51 bytes) of each LORRI image contain housekeeping information. These bytes are corrupted by LOSSY compression. Please refer to the DOCUMENT/SOC_INST_ICD.* file for details and implications in raw and calibrated datasets. 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. LOR_0123456789_0X630_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 ** =========== ================================== ============= LORRI LOR 0X630 - 0X63B * * 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) ===== =================================== 0x630 - LORRI High-res Lossless (CDH 1)/LOR 0x636 - LORRI High-res Lossless (CDH 2)/LOR 0x632 - LORRI High-res Lossy (CDH 1)/LOR 0x638 - LORRI High-res Lossy (CDH 2)/LOR 0x631 - LORRI High-res Packetized (CDH 1)/LOR 0x637 - LORRI High-res Packetized (CDH 2)/LOR 0x633 - LORRI 4x4 Binned Lossless (CDH 1)/LOR 0x639 - LORRI 4x4 Binned Lossless (CDH 2)/LOR 0x635 - LORRI 4x4 Binned Lossy (CDH 1)/LOR 0x63B - LORRI 4x4 Binned Lossy (CDH 2)/LOR 0x634 - LORRI 4x4 Binned Packetized (CDH 1)/LOR 0x63A - LORRI 4x4 Binned Packetized (CDH 2)/LOR Instrument description ---------------------Refer to the following files for a description of this instrument. CATALOG LORRI.CAT DOCUMENTS LORRI_SSR.* SOC_INST_ICD.* NH_LORRI_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 LORRI Field Of View definitions: /DOCUMENT/NH_FOV.* /DOCUMENT/NH_LORRI_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. 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-PLUTOCRUISE-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_LORRI_PLUTOCRUISE.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 occured 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 docmentation, 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 LORRI Principal Investigator: Andrew Cheng, Johns Hopkins Univ., Applied Physics Lab Andrew Cheng Johns Hopkins University Applied Physics Laboratory Space Department 11100 Johns Hopkins Road Laurel, MD 20723 USA
These data are available on-line from the Planetary Data System (PDS) at:
https://pdssbn.astro.umd.edu/holdings/nh-x-lorri-2-plutocruise-v2.0/
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Andrew F. Cheng | Data Provider | Applied Physics Laboratory | andrew.cheng@jhuapl.edu |
Dr. Brian Carcich | General Contact | Cornell University | carcich@astro.cornell.edu |