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: 2014-10-30 - NH-internal archive software version: V2.0 " RECORD_TYPE = STREAM INSTRUMENT_HOST_NAME = "NEW HORIZONS" OBJECT = DATA_SET DATA_SET_ID = "NH-X-REX-2-LAUNCH-V1.0" OBJECT = DATA_SET_INFORMATION START_TIME = 2006-04-19T12:00:01.350 STOP_TIME = 2006-06-29T16:41:15.813 DATA_SET_DESC = " Data Set Overview ================= This data set contains Raw data taken by New Horizons Radio Science Experiment instrument during the LAUNCH 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. 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. TWO-WAY RANGING DATA WILL NOT BE ARCHIVED IN REX DATA SETS. ######################################################################## ######################################################################## After launch, the REX Instrument was commissioned in a series of events conducted in the period from February 2006, to April 2007. The next paragraph was copied from Tyler et al., 2008 [TYLERETAL2008]. In the months immediately following launch, the New Horizons project initiated a series of commissioning activities designed to verify instrumental functionality and to measure the performance of the instrument complement. Commissioning of the REX instrument began with an initial test on April 19, 2006, while the spacecraft was still spinning following launch, designed to determine basic functionality and performance. This test included the exercise of calibration test patterns, the reception of an uplink signal transmitted by a DSN ground station for specific evaluation of the inflight REX system gain, linearity, stability of the composite uplink, USO, and REX receiver chain, characterization of the REX bandpass frequency response, and identification of the presence of spurious signals, if any, in the REX passband. These tests were repeated on June 1, 2006 with the spacecraft attitude stabilized on three axes. Two additional commissioning tests with three-axis attitude stabilization were conducted on June 20 and 29, 2006, for the purpose of measuring the beam pattern of the spacecraft high gain antenna (HGA), and for calibrating the REX system noise figure and radiometric sensitivity. The results of these tests, including a synopsis of the REX commissioning data, are available in Tyler et al., 2008 [TYLERETAL2008]. In summary, these commissioning tasks certified that REX was fully functional, and met all of its performance metrics. In particular, REX is free of any spurs in its occultation band, easily achieved the design target uplink capture signal to noise ratio of +55 dB/Hz, has a radiometric noise floor of ~150 K, a gain stability sufficient to achieve a radiometric sensitivity of 0.002 K, and a USO stability approaching an Allan deviation of 1 x 10^-13, well below the performance goal for the USO. Although one-way uplink data signals were sent from the Ground Element to REX, the characteristics of those signals are not needed to analyze these REX observations comprising instrument checkout, characterization and calibration activities. So no uplink tuning profiles are included in this data set. 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_LAUNCH.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. Refer to the REX documentation for more detail. 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. ALI_0123456789_0X0AB_ENG_1.FIT ^^^ ^^^^^^^^^^ ^^^^^ ^^^ ^\__/ | | | | | ^^ | | | | | | | | | | | +--File type (includes dot) | | | | | - .FIT for FITS file | | | | | - .LBL for PDS label | | | | | - not part of product ID | | | | | | | | | +-- Version number from the SOC | | | | (Science Operations Center) | | | | | | | +--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 * For those datasets where the NH project is delivering CODMAC Level 1 & 2 data (REX & PEPSSI), ENG and SCI apply to CODMAC Level 1 & 2 data, respectively. Instrument Instrument designators ApIDs =========== ================================== ============= REX REX 0X7B0 - 0X7B3 * * Not all values in this range are in this data set There are other ApIDs that contain housekeeping values and other values. See the documentation for more 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) ===== =================================== 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. 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-LAUNCH-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_LAUNCH.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 REX Principal Investigator: Len Tyler, Stanford University Len Tyler 350 Serra Mall, David Packard #372 Stanford University Stanford, CA 94305-9515 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-X-REX-2-LAUNCH-V1.0, may not have corresponding data products in the calibrated data set, NH-X-REX-3-LAUNCH-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_LAUNCH.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 by one both ten times within each data file and from the last Time Tag of one file to the first Time Tag of the next file in a sequence. 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. 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. Instead, 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 TBD. " ABSTRACT_DESC = " This data set contains Raw data taken by the New Horizons Radio Science Experiment instrument during the post-launch checkout mission phase. This is VERSION 1.0 of this data set. " CITATION_DESC = " Tyler, L., NEW HORIZONS Raw REX POST-LAUNCH CHECKOUT V1.0, NH-X-REX-2-LAUNCH-V1.0, NASA Planetary Data System, 2014. " DATA_OBJECT_TYPE = "ARRAY" DATA_SET_COLLECTION_MEMBER_FLG = "N" DATA_SET_NAME = "NEW HORIZONS REX POST-LAUNCH CHECKOUT RAW V1.0" DATA_SET_RELEASE_DATE = 2014-10-30 DATA_SET_TERSE_DESC = " Raw data taken by New Horizons Radio Science Experiment instrument during the LAUNCH 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 = "CALIBRATION" 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