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: 2016-10-31 - NH-internal archive software version: V2.0 " RECORD_TYPE = STREAM INSTRUMENT_HOST_NAME = "NEW HORIZONS" OBJECT = DATA_SET DATA_SET_ID = "NH-P-REX-2-PLUTO-V1.0" OBJECT = DATA_SET_INFORMATION START_TIME = 2015-04-08T18:16:33.775 STOP_TIME = 2015-11-20T01:01:59.874 DATA_SET_DESC = " Data Set Overview ================= This data set contains Raw data taken by New Horizons Radio Science Experiment instrument during the PLUTO mission phase. The REX instrument measures the amplitude and phase of radio signals captured by the New Horizons high-gain antenna. The main investigation is an occultation experiment which uses radio signals transmitted from Earth to probe the atmosphere and ionosphere of Pluto and Charon. Ancillary investigations include measurements of the 4 cm wavelength radiothermal emission from planets or other radio sources. Phase data may also be combined with Pluto encounter tracking data, derived from the Radio Science Subsystem separately from REX and to be archived in separate non-REX data set(s), to infer the influence of gravitational fields on the spacecraft as it moves through the Pluto system. As of July, 2016, disposition of tracking data is TDB (tracking data have not been archived). The main investigation requires coordinated use of the Earth-based transmitters and the spacecraft receiver as the two physical elements of the REX instrument. The 'Ground Element' comprises DSN (Deep Space Network) hardware and operations facilities on Earth, and the 'Flight Element' includes signal processing hardware and software onboard the spacecraft. Unless inclusion of tuning profiles for one-way uplink transmissions is noted below, this data set includes only samples taken and measurements made by the REX system hardware on-board the New Horizons spacecraft -- either of one-way uplink signals or of 4cm-wavelength thermal emission. ######################################################################## ######################################################################## REQUIRED UNDERSTANDING: THE REX AND THE NEW HORIZONS (NH) REGENERATIVE RANGING TRACKER [DEBOLTETAL2005] ARE *****SEPARATE***** AND *****INDEPENDENT***** SUBSYSTEMS THAT BOTH USE THE RADIO FREQUENCY (RF) AND TELECOMMUNICATIONS SUBSYSTEMS. TRACKING DATA WILL NOT BE ARCHIVED IN REX DATA SETS. ######################################################################## ######################################################################## 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). For this first REX delivery for the Pluto mission phase, this data set includes only the Approach data plus a subset of the CORE and departure sequences data that was downlinked through the end of January, 2016. 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, REX executed only tests and calibration sequences: test patterns; an Operational Readiness Test (ORT) on 08.April of the surface temperature double scan (THERMSCAN) and of the Pluto and Charon occulations; ride-alongs with several PEPSSI plasma rolls, which were performed with Deep Space Network (DSN) uplink tones for USO characterization; a high-power uplink test with the 34m antenna DSS-26. The timings of the plasma roll USO characterizations were planned so that the Z axis was oriented toward the Sun during rolls about the Y axis (HGA boresight) pointed to Earth: this 'Z to Sun' attitude duplicated the orientation that would occur during the Pluto and Charon occultations in the CORE sequence. From the day of encounter, this data set includes data from two CORE observations: (1) the bi-static radar THERMSCAN data, which measured DSN uplink signal reflected off of Pluto during the flyby; (2) the Pluto occultation data for both ingress and egress. There is also a backup USO Stability characterization observation taken in November, 2015, to replace a attempt in the weeks after encounter that failed due to a DSN misconfiguration. This data set also includes uplink tuning profile data in, and extracted from, Tracking and Navigation Files (TNFs) for all CORE observations. Although uplink data signals were sent from the Ground Element to REX during the Approach sub-phase, tuning profiles for those signals are not provided as they are not needed to analyze those REX Approach observations comprising instrument checkout, characterization and calibration activities. 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_REX_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. Known issues in REX data ======================== The following item assumes familiarity with the REX, REX terminology and the required reading and other documentation provided with this data set. Time tag anomalies in ROF sequences ----------------------------------- REX places ten incrementing time tags in each REX Output Frame (ROF). The time tags can be used both to identify any breaks in a sequence of ROFs, and to determine the time between any two ROFs within a sequence. The normal sequence for time tags is to start at zero in the first ROF and increment ten times per ROF, so the first time tag of the second ROF is 10, that of the third ROF is 20, etc. In practice, the first and last ROFs in a sequence do not always show simple zero starts and clean finishes, respectively, indicating data corruption in just those ROFs. There is no indication of corruption elsewhere in ROF streams, and REX commanding ensures there are always adequate ROFs before and after any observation, so discarding starting and ending ROFs in a sequence based on simple inspection of time tags is the way to handle this issue. For more detail, refer to the REX Instrument Description section in the SOC Instrument Interface Control Document (ICD). 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 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. REX_0123456789_0X7B0_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 ** =========== ================================== ============= REX REX 0X7B0 - 0X7B3 * * 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) ===== =================================== 0x7b0 - REX Lossless Compressed Data (CDH 1)/REX 0x7b1 - REX Packetized Data (CDH 1)/REX 0x7b2 - REX Lossless Compressed Data (CDH 2)/REX 0x7b3 - REX Packetized Data (CDH 2)/REX Instrument description ---------------------- Refer to the following files for a description of this instrument. CATALOG REX.CAT DOCUMENTS REX_SSR.* SOC_INST_ICD.* 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 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-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_REX_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 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 REX Principal Investigator: Ivan Linscott, Stanford University Len Tyler David Packard Building - Room 331 (MC 9515) 350 Serra Mall Stanford, CA 94305-4020 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-REX-2-PLUTO-V1.0, may not have corresponding data products in the calibrated data set, NH-P-REX-3-PLUTO-V1.0. 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_REX_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. The Time Tag counter values included with REX data normally increment nine times within each data file and once between consecutive frames. However, there are sometimes anomalous departures from this behavior at the start and end of contiguous runs of data files (see REX.CAT for a brief discussion of such an issue related to compression). Files with such anomalies are few compared to the total number of data files, and excluding those files with anomalous Time Tag data from data analysis will not significantly affect the results of the REX investigation. Refer to the Science Operations Center/instrument interface control document for more detail about REX Time Tags; there is adequate information there for users to identify anomalous files. In addition, products with Time Tag anomalies are listed in file ERRATA.TXT provided with this data set. 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 New Horizons project does not have the resources to rigorously determine and check the accuracy of the TARGET_NAME assignments in the PDS labels for the observations in this data set. An automated process using heuristics to analyze simulated operation products has been put in place to make a best effort attempt to identify the target and intent of each observation. 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. Review ====== This dataset was peer reviewed and certified for scientific use on 2017-03-30. " ABSTRACT_DESC = " This data set contains Raw data taken by the New Horizons Radio Science Experiment (REX) instrument during the Pluto encounter mission phase. This is VERSION 1.0 of this data set. This REX dataset includes operational tests and calibrations taken during the approach to Pluto, including a series of ground in the loop tests to prepare for the Pluto and Charon occultations. From the day of the Pluto Encounter, two observations are included, the bi-static radar THERMSCAN data, which measured the DSN uplink signal reflected off of Pluto during the flyby, and the Pluto occultation data for both ingress and egress. " CITATION_DESC = " Linscott, I., NEW HORIZONS Raw REX PLUTO ENCOUNTER V1.0, NH-P-REX-2-PLUTO-V1.0, NASA Planetary Data System, 2017. " DATA_OBJECT_TYPE = "ARRAY" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_SET_NAME = "NEW HORIZONS REX PLUTO ENCOUNTER RAW V1.0" DATA_SET_RELEASE_DATE = 2016-10-31 DATA_SET_TERSE_DESC = " Raw data taken by New Horizons Radio Science Experiment instrument during the PLUTO mission phase. This is VERSION 1.0 of this data set. " DETAILED_CATALOG_FLAG = "N" PRODUCER_FULL_NAME = "BRIAN CARCICH" 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 = "DEBOLTETAL2005" END_OBJECT = DATA_SET_REFERENCE_INFORMATION OBJECT = DATA_SET_TARGET TARGET_NAME = "CHARON" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "EARTH" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "N/A" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_TARGET TARGET_NAME = "PLUTO" END_OBJECT = DATA_SET_TARGET OBJECT = DATA_SET_HOST INSTRUMENT_HOST_ID = "NH" INSTRUMENT_ID = "REX" END_OBJECT = DATA_SET_HOST END_OBJECT = DATA_SET END