Data Set Overview
  =================
    This data set provides resampled (raw, averaged) temperature
    measurements from 27 sensors located in the HRII, HRIV, and MRI
    instruments and on the HRI and MRI telescopes, instrument platform,
    and solar wings of the Deep Impact flyby spacecraft.  The data
    begin on 15 January 2005, three days after launch, and continue
    through 9 July 2005, five days after the encounter with comet
    9P/Tempel 1.
 
    Most of the sensors were part of the spacecraft thermal subsystem
    which continuously controlled the thermal environment via the
    spacecraft telemetry stream.  Temperatures were recorded in the
    telemetry at various rates throughout the mission, from several
    times every hour to as frequently as once every minute whether
    the instruments were turned on or off.
 
 
  Data
  ====
    The averaged temperature measurements are provided in two, fixed-width,
    ASCII tables with detached PDS labels:
 
    HRI Temperatures Table
    ----------------------
      This table contains averaged measurements from 14 different
      temperature sensors located at various points on the HRI telescope,
      the HRI IR spectrometer (HRII) which includes the Spectral Imaging
      Module (SIM), and the HRI visible CCD (HRIV).  It also includes
      averaged measurements from a sensor in the panel underneath the
      instrument platform and four sensors located on the back side of
      the two solar wings on the flyby spacecraft:
 
           S/C
        Sensor# : AMMOS# : Sensor Description
          TS104 : T-0276 : HRI telescope barrel at center (first sensor)
          TS102 : T-0287 : HRI SIM bench at prisms (first sensor)
          TS103 : T-0296 : HRI CCD plate assembly (first sensor)
          TS118 : T-0298 : HRI beam splitter
          TS131 : T-0302 : HRI primary mirror
          TS107 : T-0303 : HRI pre-amp box
          TS134 : T-0305 : HRI IR detector cooler (secondary radiator)
          TS114 : T-0306 : HRI IR focal plane array (primary radiator)
          TS116 : T-0327 : HRI electronics box
          TS110 : T-1777 : HRI telescope barrel at center (second sensor)
          TS108 : T-1792 : HRI SIM bench at prisms (second sensor)
          TS109 : T-1793 : HRI CCD plate assembly (second sensor)
          TS115 : T-1804 : HRI SIM bench at rear flexure
          TS135 : T-1806 : Baffle extension on the HRI telescope barrel
          n/a   : T-0339 : Panel underneath the instrument platform
          TS1   : T-0275 : Back side of solar array wing 1, -Z direction
          TS3   : T-0280 : Back side of solar array wing 1, +Z direction
          TS2   : T-1776 : Back side of solar array wing 2, -Z direction
          TS4   : T-1781 : Back side of solar array wing 2, +Z direction
 
    MRI Temperatures Table
    ----------------------
      This table contains averaged measurements from nine different
      temperature sensors located at various points on the MRI telescope
      and the MRI visible CCD:
 
           S/C
        Sensor# : AMMOS# : Sensor Description
          TS132 : T-0277 : MRI optical bench at the primary mirror
          TS106 : T-0284 : MRI CCD plate assembly (first sensor)
          TS105 : T-0299 : MRI telescope box at center bottom
          TS133 : T-1778 : MRI telescope box extension
          TS112 : T-1797 : MRI CCD plate assembly (second sensor)
          TS111 : T-1800 : MRI primary mirror
          TS113 : T-1805 : MRI pre-amp box
          TS117 : T-1819 : MRI electronics box
 
    The spacecraft sensor numbers (TSnnn) and AMMOS numbers (T-nnnn),
    Advanced Multi-Mission Operations System) are provided to help
    researchers locate the thermal sensors illustrated in the Pictorial
    Atlas of Deep Impact (& EPOXI) Instrument Thermal Telemetry document
    which included in this data set.  It is important to note these
    temperature sensors are independent of those used to record
    measurements that were embedded in the science data image headers
    by the software on-board the spacecraft.
 
    These data were used by the Deep Impact science team to monitor and
    understand the thermal environment and to calibrate the HRII instrument
    which was very sensitive to temperature fluctuations.  Also, the team
    noted the readings from the two sensors for the MRI CCD varied by as
    much as one degree Celsius during flight.
 
 
  Processing
  ==========
    The raw thermal telemetry data for each sensor were averaged for
    20-minute intervals because over the entire mission it was determined
    that this interval was much shorter than time over which a thermal
    value changed by a significant amount, typically over several hours.
    Also, 20-minutes provided enough time resolution for correlating
    averaged temperatures with time stamps in the data acquired by the
    HRII, HRIV, and MRI instruments.
 
    No corrections or conversions were applied to the resulting, averaged
    temperatures.  However, the HRII spectral imaging module (SIM) bench
    temperatures recorded in the telemetry were known be one to two degrees
    different than the measurements collected by the instruments.  See the
    instrument calibration paper by Klaasen, et al. (2006) [KLAASENETAL2006]
    located in the Deep Impact Documentation data set,
    DI-C-HRII/HRIV/MRI/ITS-6-DOC-SET-V1.0.
 
    Time Stamps
    -----------
      The time stamps in tables were calculated by taking the mean of the
      spacecraft ephemeris times (SCET) for the temperature measurements
      within a 20-minute interval.  The median, when compared to the
      average, introduced a maximum uncertainty of +/- 10 minutes which
      was considered to be negligible because thermal changes occurred
      over much larger time scales.
 
      The time stamps in the tables can be used as UTC at the spacecraft
      because the SCET was good to sub-seconds compared to the UTC.
 
 
  Temperature Sensors
  ===================
    The sensors were placed on active operating components and in critical
    locations on the HRI and MRI telescopes and in the HRII infrared
    spectrometer, the HRIV CCD, and the MRI CCD, as well as on the
    instrument platform and the two solar wings of the flyby spacecraft.
    All of these sensors, except those on the instrument platform and
    solar wings, were connected to side A or B of the flyby spacecraft's
    Thermal Interface Board (TIB).  The sensors were used to monitor the
    thermal environment and, with the instrument heaters, provided a
    closed-loop temperature control via the telemetry stream.
    Measurements were recorded in the telemetry at various rates
    throughout the mission, from about once every minute to several
    times every hour whether the instruments were turned on or off.
 
    To see where the thermal telemetry points are located, please refer
    to the Pictorial Atlas of Deep Impact (& EPOXI) Instrument Thermal
    Telemetry document included in this data set.  For a discussion of
    the thermal design of the instruments, see Hampton, et al. (2005)
    [HAMPTONETAL2005].  The Deep Impact instrument calibration paper
    by Klaasen, et al. (2006) [KLAASENETAL2006] describes how various
    temperatures affect the calibration of the HRII, HRIV, and MRI
    instruments.
 
    For a list of spacecraft events such as trajectory correction maneuvers
    that may have affected the instrument temperatures, see the Deep Impact
    Mission Timeline document included with this data set.
 
 
  Media Format
  ============
    This data set is released in electronic format.
 
 
  This data set overview was prepared by Stephanie McLaughlin with input
  from Donald Hampton, the data supplier.

Review
  ======
    This date set successfully passed the PDS peer review held on
    30 April 2007, pending resolution of liens which were resolved
    on March 2008.