Data Set Information
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| DATA_SET_NAME |
DEEP IMPACT 9P/TEMPEL 1 ENCOUNTER - RADIO SCIENCE DATA V1.0
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| DATA_SET_ID |
DIF-C-RSS-1-9P-ENCOUNTER-V1.0
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| NSSDC_DATA_SET_ID |
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| DATA_SET_TERSE_DESCRIPTION |
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| DATA_SET_DESCRIPTION |
Data Set Overview : The Deep Impact (DI) comet Tempel 1 Radio Science (RS) Data Set is a time-ordered collection of raw and partially processed data collected during the DI flyby of the comet Tempel 1. Because the DI spacecraft flyby occurred at a close approach distance of 500 km and at a relatively high relative encounter velocity (10.1 km/s), there was no comet gravity signal in the tracking data and hence no gravity science. In addition, there was no evidence in the spacecraft tracking data for dust or gas drag near the time of closest approach. For information on the comet dynamics, see reference Yeomans, et al. (2005) [YEOMANSETAL2005]. The radiometric data also supported DI Navigation. The data set includes: Directory Description --------- ----------- ODF Orbit Data Files containing closed-loop (two-way) Doppler and sequential range measurements. EOP Earth-Orientation Parameter file ION Ionosphere calibration file TRO Troposphere calibration files Typical users of these data might analyze range and Doppler measurements in the ODF to derive the DI trajectory during the comet Tempel 1 flyby. Parameters : The ODF contains the most important information (range and Doppler) needed by spacecraft navigators. Each ODF is accompanied by a full PDS label which describes both the content and format of the associated file. ODF data types can include those listed below. Only those marked below with an asterisk are present in this data set ODF. Narrowband spacecraft VLBI, Doppler mode (cycles) Narrowband spacecraft VLBI, phase mode (cycles) Narrowband quasar VLBI, Doppler mode (cycles) Narrowband quasar VLBI, phase mode (cycles) Wideband spacecraft VLBI (nanoseconds) Wideband quasar VLBI (nanoseconds) * One-way Doppler (Hertz) * Two-way Doppler (Hertz) * Three-way Doppler (Hertz) One-way total count phase (cycles) Two-way total count phase (cycles) Three-way total count phase (cycles) PRA planetary operational discrete spectrum range (range units) * SRA planetary operational discrete spectrum range (range units) RE[GSTDN] range (nanoseconds) Azimuth angle (degrees) Elevation angle (degrees) Hour angle (degrees) Declination angle (degrees) X angle (where +X is east) (degrees) Y angle (where +X is east) (degrees) X angle (where +X is south) (degrees) Y angle (where +X is south) (degrees) Processing : ODF's are screened for 'bad' data points, which are removed prior to analysis by the navigation or radio science teams. However, all data are included in these archived ODF's files, including 'bad' data that may have been excluded during radio science or navigation analysis. Data : ODFs were issued approximately daily during the flyby phase, occasionally more often to support critical events such as engine-firings (for maneuvers). These ODFs are stored in the ODF directory. File name is of the form ydddeeeC.ODF where y is the one-digit year (2005 implicit) of the first data, ddd is the three-digit day-of-year of the first data, eee is the three-digit day-of-year of the last data. Symbol C denotes an alphabetic character distinguishing separate files issued during the same day. Ancillary Data : Ancillary files are needed for proper analysis and interpretation of the radio data (file type ODF). These are organized in parallel directories and stored approximately chronologically. Earth Orientation Parameter Files (EOP Directory) --------------------------------------------------- Earth Orientation Parameter files are produced by the Time and Earth Motion Precision Observation (TEMPO) Group at JPL. They are ASCII files with variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) and an ASCII line-feed (ASCII 10). EOP files, issued three times a week, include results based on fits to historical data as well as extrapolated predictions into the future. Subsequent file releases gradually replaced predict-intervals with data-based actual values. In this archive, one file has been selected such that it covers the DI flyby phase with data-based actual values. The file name has the form ydddzeee.EOP where y is the one-digit year of the first data in the file (2000 is implicit), ddd is the day-of-year of the first data in the file, z is the one-digit year of the last data, and eee is the day-of-year of the last data in the file. The file covers the previous nine months of past motion, with prediction for three months into the future; files are typically 30 KB. The EOP file is accompanied by a PDS minimal label with file name ydddzeee.LBL. Ionosphere Calibration Files (ION Directory) --------------------------------------------------- Ionosphere Calibration files are produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. These are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) and an ASCII line-feed (ASCII 10). The file name has the form ydddzeee.ION where y is the one-digit year of the first data in the file (2000 is implicit), ddd is the day-of-year of the first data in the file, z is the one-digit year of the last data in the file (2000 is implicit), and eee is the day-of-year of the last data in the file. ION files were released at one week intervals to cover a single month and included predicts for the rest of the month. The single file archived here is a concatenation of file releases that were issued at the start of a month, containing actual measured values for the month just past. The ION file is accompanied by a PDS minimal label with file name ydddzeee.LBL. Troposphere Calibration Files (TRO Directory) --------------------------------------------------- Troposphere Calibration files are produced by the Tracking System Analytic Calibration (TSAC) Group at JPL. These are ASCII files of variable length records. Each record is delimited by an ASCII carriage-return (ASCII 13) and an ASCII line-feed (ASCII 10). File names have the form ydddzeee.TRO where y is the one-digit year of the first data in the file, ddd is the day-of-year of the first data in the file, z is the one-digit year of the last data in the file and eee is the day-of-year of the last data in the file. File 51525213.TRO contains measured data from 2005-June-01 to 2005-Aug-01. It is a concatenation of individual files released at the beginning of each month, covering the previous month. File 20018001.TRO contains a seasonal/cyclical adjustment for each site, interpreted by software as being applicable from 1972-Jan-1 to 2048-Jan-1. Each TRO file is accompanied by a PDS minimal label with file name ydddzeee.LBL. Coordinate System : Analysis was conducted in the frame of the DE-405 solar system model, aligned with the 1993 ICRF/J2000 reference frame. Software : Software for parsing, reducing, and analyzing data such as these has been developed at several institutions and elsewhere. Because such software must usually operate at the bit-level and is written for a narrow range of platforms, it is not suitable for general distribution. No software is included with this archival data set.
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| DATA_SET_RELEASE_DATE |
2006-06-28T00:00:00.000Z
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| START_TIME |
2005-06-27T12:00:00.000Z
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| STOP_TIME |
2005-07-11T12:00:00.000Z
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| MISSION_NAME |
DEEP IMPACT
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| MISSION_START_DATE |
2005-01-12T12:00:00.000Z
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| MISSION_STOP_DATE |
2005-07-13T12:00:00.000Z
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| TARGET_NAME |
9P/TEMPEL 1 (1867 G1)
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| TARGET_TYPE |
COMET
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| INSTRUMENT_HOST_ID |
DIF
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| INSTRUMENT_NAME |
RADIO SCIENCE SUBSYSTEM
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| INSTRUMENT_ID |
RSS
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| INSTRUMENT_TYPE |
RADIO SCIENCE
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| NODE_NAME |
Small Bodies
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| ARCHIVE_STATUS |
ARCHIVED
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| CONFIDENCE_LEVEL_NOTE |
Overview : Data in this archival data set have been processed as part of the activities of the DI Navigation Team. This is an excellent data set. Review : Prior to creation of the final version of the archival data set, key elements of the archive were distributed for preliminary review. These included electronic versions of example PDS labels, CATALOG files, and Software Interface Specifications (SIS). These materials were distributed to PDS personnel, the experiment investigator, and others, as appropriate. Data Coverage and Quality : Significant events for Radio Science during Tempel 1 flyby phase are as follows: Summary of DI Maneuvers at comet Tempel 1 2005 June 23 to 2005 July 11 Time lng DV R.A. Dec. PreTCM PostTCM Event Date (UTC) (sec) (m/s) (deg.) (deg.) (kg) (kg) ----- ------------ ------- ------- ------- ------- ------ ------ TCM-3B 23 Jun 19:00 62.448 6.002 22.281 -24.717 958.40 955.47 TCM-5.1 3 Jul 00:00 20.912 0.322 110.460 1.785 955.42 955.43 Divert-D.1 3 Jul 06:12 658.470 102.569 23.976 -27.448 583.67 558.04 Table Column meanings: lng: solved-for duration of engine firing in seconds DV: solved-for velocity change (delta-V) in m/s DV, R.A. and Dec. are achieved maneuver parameters w.r.t. EME2000. Right Ascension and Declination describe the orientation of the maneuver velocity in the EME2000 frame. Right Ascension is angle between coordinate system X-axis and the maneuver (delta V) vector projected on the Equatorial Plane and Declination is the angle between equatorial plane and the maneuver vector. PreTCM: mass before the trajectory correction maneauver (TCM) in kg PostTCM: mass after the TCM in kg. PreTCM and PostTCM masses were obtained from the attitidue control system after each maneauver. Limitations : The limitations in this data set derive from tracking geometry and measurement data types. There are no known general or systematic defects in the data.
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| CITATION_DESCRIPTION |
ABSTRACT_DESC and keywords andGiorgini, J. D. and D. K. Yeomans, DEEP IMPACT 9P/TEMPEL 1 ENCOUNTER - RADIO SCIENCE DATA V1.0, DIF-C-RSS-1-9P-ENCOUNTER-V1.0. NASA Planetary Data System, 2006.
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| ABSTRACT_TEXT |
This data set contains raw radio science data from the Deep Impact flyby spacecraft, collected during the encounter with comet 9P/Tempel 1.
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| PRODUCER_FULL_NAME |
JON D. GIORGINI
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| SEARCH/ACCESS DATA |
SBN Comet Website
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