| DATA_SET_DESCRIPTION |
Data Set Overview
=================
This dataset contains the raw and smoothed (averaged) instrument
thermal telemetry for the entire EPOXI mission, from 04 October 2007
through 06 February 2011. Measurements were collected by 59 thermal
sensors located in the HRII, HRIV, and MRI instruments, on the
instrument platform, and on the solar wings of the Deep Impact flyby
spacecraft. Version 2.1 corrects a typo in a column description
in 5 data labels, hri_raw_i_temps_*.lbl.
Temperature Sensors
===================
The raw and smoothed temperatures provided in this dataset are
from two independent types of sensors:
1) One set is part of the spacecraft thermal subsystem
which continuously control the thermal environment via
the spacecraft telemetry stream, and
2) The other set records the measurements embedded in the
science data image headers by the software on-board the
spacecraft.
The spacecraft thermal subsystem are 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, are connected to side A or B of
the flyby spacecraft's Thermal Interface Board (TIB). The sensors are
used to monitor the thermal environment and, with the instrument
heaters, provided a closed-loop temperature control via the telemetry
stream. Measurements are 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.
The instrument thermal sensors are also 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
instruments, sometimes in close proximity to sensors connected to the
spacecraft thermal subsystem. However most of the instruments sensors
only record measurements when an instrument is turned on. Measurements
are recorded in the science image headers and in the telemetry at
various rates throughout the mission, from about once every minute to
several times every hour.
The Pictorial Atlas of Deep Impact and EPOXI) Instrument Thermal
Telemetry document included in this dataset illustrates the location
of the thermal telemetry points (sensors) are located. The thermal
design of the instruments is described by Hampton, et al. (2005)
[HAMPTONETAL2005]. The Deep Impact instrument calibration paper by
Klaasen, et al. (2008) [KLAASENETAL2006] and the EPOXI instrument
calibration paper by Klaasen, et al. (2011) describe how various
temperatures affect the calibration of the HRII, HRIV, and MRI
instruments. A draft of the Deep Impact document and summary of EPOXI
document are included in this dataset.
Data
====
Raw thermal measurements received in the original telemetry stream
from the flyby spacecraft were extracted, grouped by type ('T' for the
spacecraft thermal subsystem and 'I' for the instrument sensors) and
year of data acquisition, then formatted into fixed-width ASCII tables
with filenames of {HRI,MRI}_RAW_{T,I}_YYYY.TAB and placed in the
DATA/RAW/ path of this dataset. Each sensor measurement is provided
as both raw data numbers and in the engineering unit (kelvin or
degrees Celsius). No corrections or conversions were applied to the
raw values.
The tools used to extract the measurements from the engineering
telemetry have been run in a mode called 'report on change only with
channel clear', such that for each sensor the tools excluded
subsequent contiguous measurements that are the same as the previous
measurement.
The raw thermal measurements were smoothed by averaging all
measurements for each sensor within a 20-minute interval. The
resulting averages were also grouped by type ('T' for the spacecraft
thermal subsystem and 'I' for the instrument sensors) and year of data
acquisition, formatted into fixed-width ASCII tables with filenames of
{HRI,MRI}_SMOOTH_{T,I}_YYYY.TAB and placed in the DATA/SMOOTH/ path of
this dataset. Each raw averaged temperature is provided in the
engineering unit (kelvin or degrees Celsius), and a count of the
values used to compute that average is included. No corrections or
conversions were applied to the values.
This dataset contains raw and smoothed temperatures for these sensors
which are illustrated in the Pictorial Atlas of Deep Impact & EPOXI
Instrument Thermal Telemetry:
Spacecraft Thermal Subsystem, HRI 'T' Sensors
---------------------------------------------
S/C AMMOS*
Sensor# : Telem# : Sensor Description
TS104 : T-0276 : HRI tele. 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 tele. 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 : HRI telescope barrel baffle extension
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**
* AMMOS Advanced Multi-Mission Operations System
** Not shown in the Pictorial Atlas
Spacecraft Thermal Subsystem, MRI 'T' Sensors
---------------------------------------------
S/C
Sensor# : AMMOS# : Sensor Description
TS132 : T-0277 : MRI optical bench at 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
Instrument, HRI 'I' Sensors
---------------------------
Instr
Sensor# : AMMOS# : Sensor Description
n/a : I-0221 : HRI instrument controller board
n/a : I-0223 : HRI CCD signal processing board
n/a : I-0225 : HRI IR signal processing board
n/a : I-0227 : HRI mechanism and telemetry board
n/a : I-0229 : HRI low voltage power supply board
AD590PAMP : I-0231 : HRI pre-amp box
PTS1 : I-0233 : HRI CCD plate assembly
PTS2 : I-0235 : SIM bench at prism (close to prism #1)
PTS3 : I-0237 : HRI primary mirror
PTS4 : I-0239 : HRI secondary mirror;
PTS5 : I-0241 : HRI SIM cover at motor bracket
PTS6 : I-0243 : HRI SIM cover at the rear flexure
PTS7 : I-0245 : HRI telescope barrel at primary mirror
PTS8 : I-0247 : HRI telescope barrel baffle extension at 2nd mirror
PTS9 : I-0249 : HRI SIM bench at motor bracket
PTS10 : I-0251 : HRI CCD filter wheel and shutter motor bracket
n/a : I-0342 : On-chip IR focal plane array
Instrument, MRI 'I' Sensors
--------------------------
Instr
Sensor# : AMMOS# : Sensor Description
n/a : I-1221 : MRI instrument controller board
n/a : I-1223 : MRI CCD signal processing board
n/a : I-1227 : MRI mechanism and telemetry board
n/a : I-1229 : MRI low voltage power supply board
AD590PAMP : I-1231 : MRI pre-amp box
PTS12 : I-1233 : MRI CCD plate assembly
PTS12 : I-1235 : MRI optical bench at rear flexure
PTS13 : I-1237 : MRI primary mirror
PTS14 : I-1239 : MRI secondary mirror;
PTS15 : I-1241 : MRI cover top plate
PTS16 : I-1243 : MRI side panel radiator
PTS17 : I-1245 : MRI telescope box top at primary mirror
PTS18 : I-1247 : MRI telescope box top at secondary mirror
PTS19 : I-1249 : MRI telescope box bottom at secondary mirror
PTS20 : I-1251 : MRI CCD filter wheel and shutter motor bracket
Media Format
============
This data set is released in electronic format.
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