Data Set Information
DATA_SET_NAME DEEP IMPACT 9P/TEMPEL ENCOUNTER - RAW HRII SPECTRA V1.0
DATA_SET_ID DIF-C-HRII-2-9P-ENCOUNTER-V1.0
NSSDC_DATA_SET_ID
DATA_SET_TERSE_DESCRIPTION
DATA_SET_DESCRIPTION Data Set Overview : This data set contains raw comet 9P/Tempel 1 spectra and science calibration data acquired by the Deep Impact High Resolution Instrument Infrared Spectrometer (HRII) during the 9P encounter phase of the mission. The 9P/Tempel 1 spectra are described in 'Deep Imact: The Anticipated Flight Data' by Klaasen, et al. (2005) [KLAASENTAL2005]. For more details about the spectra taken around impact, refer to the HRII encounter data summary document which provides a log of the exposures taken from 28 hours before impact through lookback. The HRII encounter pointing summary document describes the pointing and scan direction for exposures taken at encounter. The raw spectra for science calibrations are described in the 'Deep Impact In-Flight Calibration Summary' document and are also discussed in the 'Deep Impact: Anticipated Flight Data' paper by Klaasen, et al. (2005) [KLAASENETAL2005]. Calibration targets included 16 Cyg A, 47 Tuc, Beta Hyi, Sirius, Vega, HD 60753, HD 79447, NGC 7027, and dark frames. For a detailed discussion of how the instrument was calibrated, see the 'Deep Impact Instrument Calibration' paper by Klaasen, et al. (2006) [KLAASENETAL2006]. A list of the raw 9P/Tempel 1 and science calibration spectra in the data set is provided below. Comet sequences executed from 1 May through 20 Jun 2005 were off target because incorrect pointing instructions were uploaded to the spacecraft. However, these images were included in this data set for completeness. Mid-Obs Exposure IDs Date DOY Minimum Maximum Mission Activity ---------- --- ------- ------- ------------------------------- 2005-05-01 121 5000100 5000100 Daily comet imaging (off target) 2005-05-07 127 5000700 5000701 Daily comet imaging (off target) 2005-05-08 128 5000800 5000803 Daily comet imaging (off target) 2005-05-10 130 5100000 5300000 May science cal 2005-05-11 131 5400000 5600000 May science cal 2005-05-12 132 5700000 5800059 May science cal 2005-05-15 135 5001500 5001504 Daily comet imaging (off target) 2005-05-16 136 5001600 5001605 Daily comet imaging (off target) 2005-05-17 137 5001700 5001705 Daily comet imaging (off target) 2005-05-18 138 5001800 5001805 Daily comet imaging (off target) 2005-05-19 139 5001900 5001905 Daily comet imaging (off target) 2005-05-25 145 5002500 5002505 Daily comet imaging (off target) 2005-05-26 146 5002600 5002604 Daily comet imaging (off target) 2005-05-27 147 5002700 5002704 Daily comet imaging (off target) 2005-05-28 148 5002800 5002805 Daily comet imaging (off target) 2005-05-28 148 5910000 5910036 IR LUT upload test 2005-05-29 149 5002900 5002905 Daily comet imaging (off target) 2005-05-30 150 5003000 5003005 Daily comet imaging (off target) 2005-05-31 151 5003100 5003101 Daily comet imaging (off target) 2005-06-03 154 6000300 6000305 Daily comet imaging (off target) 2005-06-04 155 6000400 6000405 Daily comet imaging (off target) 2005-06-05 156 6000500 6000501 Daily comet imaging (off target) 2005-06-07 158 6100000 6300000 June science cal 2005-06-08 159 6400000 6500000 June science cal 2005-06-10 161 6700000 6800048 June science cal 2005-06-10 161 6001001 6001002 Daily comet imaging (off target) 2005-06-11 162 6001100 6001103 Daily comet imaging (off target) 2005-06-12 163 6001200 6001201 Daily comet imaging (off target) 2005-06-13 164 6001300 6001304 Daily comet imaging (off target) 2005-06-14 165 6001400 6001403 Daily comet imaging (off target) 8700000 8800000 Pre-impact science mini-cal test 2005-06-15 166 6001500 6001505 Daily comet imaging (off target) 2005-06-16 167 6001600 6001602 Daily comet imaging (off target) 5910000 5910036 IR LUT upload test 2005-06-17 168 6001700 6001704 Daily comet imaging (off target) 2005-06-18 169 6001800 6001803 Daily comet imaging (off target) 2005-06-19 170 6001900 6001905 Daily comet imaging (off target) 2005-06-20 171 6002000 6002004 Daily comet imaging (off target) 6002005 6002005 Daily comet imaging (on target) 2005-06-21 172 6002100 6002105 Daily comet imaging 2005-06-22 173 6002200 6002205 Daily comet imaging 2005-06-23 174 6002300 6002305 Daily comet imaging 2005-06-24 175 6002400 6002405 Daily comet imaging 2005-06-25 176 6002500 6002504 Daily comet imaging 2005-06-26 177 6002600 6002603 Daily comet imaging 2005-06-27 178 8000000 8000005 Continuous comet imaging 2005-06-28 179 8000005 8100004 Continuous comet imaging 2005-06-29 180 8100005 8300000 Continuous comet imaging 2005-06-30 181 8400000 8400005 Continuous comet imaging 2005-07-01 182 8400006 8500009 Continuous comet imaging 2005-07-02 183 8500009 8600003 Continuous comet imaging 8700000 8700005 Pre-impact science mini-cal 8800000 8800003 Continuous comet imaging 2005-07-03 184 9000000 9000007 Continuous comet imaging 9000008 9000017 Pre-impact dark cal 9000018 9000021 Continuous comet imaging 2005-07-04 185 9000022 9000029 Continuous comet imaging 9000030 9000039 Pre-impact scans 9000040 9000068 Impact imaging 9010000 9070002 Lookback imaging 2005-07-05 186 9080000 9110002 Lookback imaging 2005-07-06 187 9120000 9150002 Lookback imaging 2005-07-07 188 7200000 7200001 Post-encounter science cal 2005-07-08 189 7200002 7200048 Post-encounter science cal 2005-07-09 190 7300000 7400005 Post-encounter science cal Essential Reading ----------------- The following documents, located on the Deep Impact Documentation volume, DIDOC_0001, are essential for the understanding and interpretation of this data set: ANTICIPATED_FLIGHT_DATA.* : Anticipated flight data by Klaasen, et al. (2005) [KLAASENTAL2005] HRII_ENCOUNTER_DATA_SUMMARY.* : Image log from 28 hours before impact through lookback HRII_ENCOUNTER_POINTING_SUMM.* : Pointing and scan directions for encounter data INFLIGHT_CALIBRATION_SUMMARY.* : Summary of in-flight calibrations CALIBRATION_DOC.* : Instrument calibration by Klaasen, et al. (2006) [KLAASENETAL2006] INSTRUMENTS_HAMPTON.* : Instrument paper by Hampton, et al. (2005) [HAMPTONETAL2005] MISSION_OVERVIEW_AHEARN.* : Mission overview by A'Hearn, et al. (2005) [AHEARNETAL2005B] SCLK_CORRELATION.* : Discussion of the discrepancy between the spacecraft clocks and UTC AIDC_FLIGHT_HRII.* : Description of the data set and definitions of label keywords Related Data Sets ----------------- The following PDS data sets are related to this one: DIF-CAL-HRII-2-9P-CRUISE-V1.0 : Raw HRII cruise calib data DIF-C-HRII-3/4-9P-ENCOUNTER-V1.0 : Reduced HRII encounter data DIF-CAL-HRII-2-GROUND-TV1-V1.0 : HRII pre-flight calib data DIF-CAL-HRII/HRIV-2-GROUND-TV2-V1.0 : HRII pre-flight calib data DIF-CAL-HRII/HRIV/MRI-2-GROUND-TV4-V1.0 : HRII pre-flight calib data DI-C-SPICE-6-V1.0 : SPICE kernels Processing : The uncompressed and compressed FITS images in this data set were created by the Deep Impact Science Data Center (SDC) at Cornell University and were assembled from raw telemetry packets sent down by the flyby spacecraft. Information from the embedded spacecraft header (the first 100 bytes of an uncompressed or 50 bytes of a compressed image) was extracted and stored in the primary FITS header. Geometric parameters were computed using the best available SPICE kernels and the results were also stored in the FITS header. If telemetry packets were missing, the corresponding pixels were flagged as missing in the quality map included as a FITS 'IMAGE' extension. The image quality map was described in the calibration pipeline section of the 'Deep Impact Instrument Calibration' paper by Klaasen, et al. (2006) [KLAASENETAL2006]. The SDC did not apply any type of correction or decompression algorithm to the raw data. Applied Coherent Technology Corporation in Herndon, VA, produced the PDS data labels by extracting parameters from the FITS headers. Data : Spectral Images --------------- The two-dimensional, infrared spectral images in this data set are in FITS format. The primary data array contains the spectral image, with the fastest varying axis corresponding to increasing wavelengths and the slowest varying axis providing the spatial dimension. It is followed by an image extension that contains a pixel-by-pixel quality map. Each FITS file is accompanied by a detached PDS label. Compression ----------- This data set contains compressed and uncompressed raw FITS images, that is, data as they were received on the ground. Data compression was performed on board the spacecraft using a set of four lossy lookup tables. A compressed FITS image consisted of 14-bit values compressed and stored as a one-byte pixel. An uncompressed FITS image consisted of 14-bit pixels stored as two bytes. The COMPRESSED_IMAGE_VALUE in the data label indicates if an raw image is compressed or uncompressed. The COMPRESSOR_ID identifies the lookup table that was used to compress an image. The calibration pipeline decompressed raw images. For information about data compression, refer to 'An Overview of the Instrument Suite for the Deep Impact Mission' by Hampton, et al. (2005) [HAMPTONETAL2005] or the instrument calibration paper by Klaasen, et al. (2006) [KLAASENETAL2006]. Target Name and Description --------------------------- The TARGET_NAME keyword in the data labels was set to the intended target, either '9P/Tempel 1' or 'Calibration'. The TARGET_DESC keyword provides the name of the specific calibration target, such as 'Dark'. True-Sky ''As Seen By Observer'' Display ---------------------------------------- A true-sky view is achieved by displaying the image using the standard FITS convention: the fastest-varying axis (samples) increasing to the right in the display window and the slowest- varying axis increasing to the top. This convention is also defined in the image labels: SAMPLE_DISPLAY_DIRECTION : 'RIGHT' LINE_DISPLAY_DIRECTION : 'UP' This topic is discussed in detail in the 'Quadrant Nomenclature' section of the 'Deep Impact Instrument Calibration' document. The direction to Celestial North and Ecliptic North, measured clockwise from the top of the displayed image, is provided in PDS labels by CELESTIAL_NORTH_CLOCK_ANGLE and SOLAR_NORTH_POLE_CLOCK_ANGLE, both of which assume the correct display defined by SAMPLE_DISPLAY_DIRECTION and LINE_DISPLAY_DIRECTION. File Naming Convention ---------------------- The naming convention for the data labels and FITS files is HIcccccccccc_eeeeeee_nnn.LBL or FIT where cccccccccc is the spacecraft clock count at the mid-point of the observation, eeeeeee is the exposure ID (OBSERVATION_ID in data labels). Up to 999 individual images could be commanded for one exposure ID. Therefore, nnn in the file name provides the sequentially increasing image number within an exposure ID corresponding to IMAGE_NUMBER in the data labels. For example, if two images were commanded for exposure ID 9000022, the two FITS files names would be HI0173709840_9000022_001.FIT and HI0173709840_9000022_002.FIT. For the HRII instrument, multiple images for one exposure ID indicate a scan of the target. Parameters : Data Units ---------- Raw image data are in units of raw data numbers. Imaging Modes ------------ For a description of the imaging modes, please see the Deep Impact instrument paper by Hampton, et al. (2005) [HAMPTONETAL2005]. Time-Related Keywords --------------------- All time-related keywords in the data labels, except EARTH_RECEIVED_TIME, are based on the clock on board the flyby spacecraft. EARTH_RECEIVED_TIME provides the UTC when an Earth-based observer should have been able to see an event recorded by the instrument. The TIME_FROM_IMPACT_VALUE keyword in the data labels was based on the estimated impact time at the flyby spacecraft of UTC 05:44:35.821 on 4 Jul 2005. Geometry-Related Keywords ------------------------- The SDC attempted to calculate geometric parameters relating to the target only when it was within several fields of view of the instrument boresight. When these parameters could not be calculated, the corresponding keywords in the PDS data labels were set to a value of unknown (UNK). Also, geometry-related keywords for calibration targets such as Canopus were set to UNK. Geometry-related parameters in the PDS data labels are uncertain at a level of a few seconds because of a known 2-second discrepancy between the clocks on board the flyby and impactor spacecraft and between in-situ data and ground-based observations. The Deep Impact project generated self-consistent SPICE kernels, outside of NAIF, to help account for the discrepancy. The November 2005 version of these kernels was used to calculate the image times and geometric information in PDS data labels. After further analysis of the timing problem in early 2006, improved self-consistent SPICE kernels were generated by the Deep Impact project. These kernels are included in the DI SPICE data set. For more information about this discrepancy, please see the spacecraft clock correlation document included on the Deep Impact document volume. Ancillary Data : Geometric parameters included in the data labels were computed using the November 2005 version of the SPICE data. These were the best available data at the time of image creation. Since image creation, some SPICE data have been improved, and these newer kernels are archived in the Deep Impact SPICE data set. Coordinate System : Earth Mean Equator and Vernal Equinox of J2000 (EME J2000) was the inertial reference system used to specify observational geometry parameters in the data labels. Geometric parameters provided in the data labels were computed at the epoch specified by MID_IMAGE_TIME, except for the target-to-sun and earth-observer-to-target parameters. Target-to-sun values were calculated for the time when the light left the sun while earth-observer-to-target were calculated for the time when the light left the target.
DATA_SET_RELEASE_DATE 2005-12-31T00:00:00.000Z
START_TIME 2005-05-01T07:58:31.416Z
STOP_TIME 2005-07-09T03:33:27.751Z
MISSION_NAME DEEP IMPACT
MISSION_START_DATE 2005-01-12T12:00:00.000Z
MISSION_STOP_DATE 2005-07-13T12:00:00.000Z
TARGET_NAME CALIBRATION
9P/TEMPEL 1 (1867 G1)
TARGET_TYPE CALIBRATION
COMET
INSTRUMENT_HOST_ID DIF
INSTRUMENT_NAME DEEP IMPACT HIGH RESOLUTION INSTRUMENT - IR SPECTROMETER
INSTRUMENT_ID HRII
INSTRUMENT_TYPE INFRARED SPECTROMETER
NODE_NAME Small Bodies
ARCHIVE_STATUS ARCHIVED
CONFIDENCE_LEVEL_NOTE Confidence Level Overview : As noted above, the geometry-related parameters in the PDS data labels are uncertain at a level of a few seconds because of a known 2-second discrepancy between the clocks on board the flyby and impactor spacecraft and between in-situ data and ground-based observations. For more information about this discrepancy, please see the spacecraft clock correlation document included on the Deep Impact document volume. The FITS files in this data set were reviewed internally by the Deep Impact project and were used extensively by the science team to calibrate the instruments. Review : This data set passed a PDS peer review that took place on April 5, 2006. Reviewers stated these data should be archived pending resolution of the liens produced during the review. Data Coverage and Quality : All expected data were received on the ground and are included in this data set. Horizontal striping through some images indicates missing data. The image quality map extension identifies where pixels are missing. If the second most-significant bit of a pixel in the image quality map is turned on, then data for the corresponding image pixel is missing. For more information, refer to the notes about image quality map in the PDS data label or to the 'Deep Impact Instrument Calibration' paper. Limitations : HRI Telescope Focus ------------------- Early images of stars using the HRI visible CCD indicated the HRI telescope was out of focus. However, this focus problem did not affect the HRII instrument. For more details, please see the instrument calibration paper by Klaasen et al. (2006) [KLAASENETAL2006]. Displaying Images ----------------- Flight software overwrote the first 50 uncompressed (or 100 compressed) pixels of first quadrant read out from the instrument with an image header. These original header pixels were included in the raw FITS images. Since the values in these pixels vary dramatically, it recommended that the values of the MINIMUM and MAXIMUM keywords in the PDS data label (or the MINPVAL and MAXPVAL in the FITS header) be used to scale an image for display because these values exclude the header bytes as well as the reference rows and columns located around the edge of the spectral image. The location of the header pixels in a displayed FITS image depends on the readout order of the instrument, as discussed in the quadrant nomenclature section of the 'Deep Impact Instrument Calibration' paper.
CITATION_DESCRIPTION McLaughlin, S. A., B. Carcich, T. McCarthy, M. Desnoyer, and K.P. Klaasen, DEEP IMPACT 9P/TEMPEL ENCOUNTER - RAW HRII SPECTRA V1.0, DIF-C-HRII-2-9P-ENCOUNTER-V1.0, NASA Planetary Data System, 2005.
ABSTRACT_TEXT This data set contains raw 9P/Tempel 1 and science calibration spectra acquired by the Deep Impact High Resolution Instrument Infrared Spectrometer during the 9P encounter phase of the mission.
PRODUCER_FULL_NAME STEPHANIE MCLAUGHLIN
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