| DATA_SET_DESCRIPTION |
Stardust Dust Flux Monitor Instrument Data Description:
=======================================================
Data Set Overview:
=================
This volume contains dust events collected during the early cruise
phase by the Dust Flux Monitor Instrument (DFMI) flown onboard
the STARDUST satellite. The data in this archive are organized
into two ASCII tables, using the same record layout. The first
table, dfmicru001.tab, provides data readout at the ''CRUISE'' rate
(as often as 10 Hz but as infrequently as every 20 minutes). The
second table, dfmienc001.tab, provides test data readout at the
''ENCOUNTER'' rate (as often as 10 Hz but at least every second).
Instrument Description:
=======================
The Dust Flux Monitor Instrument (DFMI) will carry out
quantitative measurements of particle impact rate and particle
mass distribution throughout the flyby of Comet Wild-2. There
are two PVDF sensor units, each measuring different mass
densities, as well as two acoustic sensors. Please refer to
both the DFMI Calibration report and the papers provided in the
/EXTRAS directory on this archive.
General notes regarding fields of the data tables:
==================================================
* Strings appear in quotes.
* Integers and PDS times do not require quotes.
* If a field is unknown, UNK may be entered.
* If a field is not applicable, N/A may be entered.
Definition of the fields in the data tables:
============================================
EVENT_SEQUENCE_NUMBER: The number associated with an
event in the file DFMICRU001.TAB,
with 1 being the first event
recorded and n being the n'th
event recorded.
SPACECRAFT_UTC_TIME: The time at which data was
obtained in UTC.
SPACECRAFT_CLOCK_TIME: The time at which data was obtained
in seconds from 1980-01-01T00:00:00.
DFMI_CLOCK_TIME: The time at which data was obtained,
with one second resolution. This
16 bit counter rolls over to 0
after 65535.
DFMI_SYNC: This column should be equal to A5,
the sync value for the DFMI data
stream.
DFMI_MODE: Indicates if DFMI is in calibration
or normal mode. Valid values are
NORM, IFC1, IFC2, IFC3, IFC4. See
DFMI Calibration Document for more
details.
DFMI_READOUT_RATE: Indicates the Readout rate: valid
values are CRUISE and ENCOUNTER.
Cruise indicates that DFMI will
read out data as often as 10Hz but
as little as every 20 minutes.
Encounter indicates that data will
be read out as often as 10Hz, but
at least every second.
DFMI_WATCHDOG_RESET: Indicates that a watchdog reset
prompted the reset of the DFMI
computer. This value will only
remain set for a single readout
period.
DFMI_SMALL_SENSOR_GAIN: DFMI small sensor sensitivity is
either HIGH or LOW. If this value
is High, the sensitivity relay is
off and the small sensor is in the
low mass range. If this value is
Low, the relay is on and the
sensor is set to the high mass
range. In the high mass range, all
electronic thresholds for the
small dust sensor are a factor 10
greater than the low mass values.
See the DFMI Calibration Document
for more details.
DFMI_ACOUSTIC_BUMPERLOW: Acoustic Bumper Low is an 8-bit
counter associated with low
threshold of impact sensor 1, also
known as the Bumper acoustic
sensor.
DFMI_ACOUSTIC_BUMPERHIGH: Acoustic Bumper High is an 8-bit
counter associated with high
threshold of impact sensor 1, also
known as the Bumper acoustic
sensor.
DFMI_ACOUSTIC_NEXTELLOW: Acoustic Nextel Low is an 8-bit
counter associated with low
threshold of impact sensor 2, also
known as the Nextel acoustic
sensor.
DFMI_ACOUSTIC_NEXTELHIGH: Acoustic Nextel High is an 8-bit
counter associated with low
threshold of impact sensor 1, also
known as the Nextel acoustic
sensor.
DFMI_CCC1_LARGEM1: CCC1 is a 16-bit counter associated
with the first (lowest) large
threshold M1. See DFMI
Calibration Document for more
details.
DFMI_CCC2_LARGEM2: CCC2 is a 16-bit counter associated
with the second large sensor
threshold M2. See DFMI
Calibration Document for more
details.
DFMI_CCC3_LARGEM3: CCC3 is a 16-bit counter associated
with the third large sensor
threshold M3. See DFMI
Calibration Document for more
details.
DFMI_CCC4_LARGEM4: CCC4 is a 16-bit counter associated
with the fourth large sensor
threshold M4. See DFMI
Calibration Document for more
details.
DFMI_CCC5_SMALLM1: CCC5 is a 16-bit counter associated
with the first (lowest) small
sensor threshold m1. See DFMI
Calibration Document for more
details.
DFMI_CCC6_SMALLM2: CCC6 is a 16-bit counter associated
with the second small sensor
threshold m2. See DFMI
Calibration Document for more
details.
DFMI_CCC7_SMALLM3: CCC7 is a 16-bit counter associated
with the third small sensor
threshold m3. See DFMI
Calibration Document for more
details.
DFMI_CCC8_SMALLM4: CCC8 is a 16-bit counter associated
with the fourth small sensor
threshold m4. See DFMI
Calibration Document for more
details.
DFMI_EB_TEMP: Temperature of the DFMI Electronics
Box, measured in Kelvin units.
DFMI_SU_TEMP: Temperature of the DFMI Sensor
Unit, measured in Kelvin.
DFMI_HEATER_POWER: Power condition, ON or OFF, of the
DFMI Heater.
SC_X_POS_WRT_SUN This element provides the x,y,z
SC_Y_POS_WRT_SUN position of the spacecraft
SC_Z_POS_WRT_SUN: measured with respect to the sun,
expressed in J2000 Earth Mean
Equator and Vernal Equinox
coordinates corrected for light
time and stellar aberration.
SC_X_VEL_WRT_SUN This element provides the x,y,z
SC_Y_VEL_WRT_SUN velocity of the spacecraft
SC_Z_VEL_WRT_SUN: measured with respect to the sun,
expressed in J2000 Earth Mean
Equator and Vernal Equinox
coordinates corrected for light
time and stellar aberration.
SC_X_POS_WRT_WILD2 This element provides the x,y,z
SC_Y_POS_WRT_WILD2 position of the spacecraft
SC_Z_POS_WRT_WILD2: measured with respect to Wild 2,
expressed in J2000 Earth Mean
Equator and Vernal Equinox
coordinates corrected for light
time and stellar aberration.
SC_X_VEL_WRT_WILD2 This element provides the x,y,z
SC_Y_VEL_WRT_WILD2 velocity of the spacecraft
SC_Z_VEL_WRT_WILD2: measured with respect to Wild 2,
expressed in J2000 Earth Mean
Equator and Vernal Equinox
coordinates corrected for light
time and stellar aberration.
SC_X_POS_WRT_EARTH This element provides the x,y,z
SC_Y_POS_WRT_EARTH position of the spacecraft
SC_Z_POS_WRT_EARTH: measured with respect to Earth,
expressed in J2000 Earth Mean
Equator and Vernal Equinox
coordinates corrected for light
time and stellar aberration.
SC_X_VEL_WRT_EARTH This element provides the x,y,z
SC_Y_VEL_WRT_EARTH velocity of the spacecraft
SC_Z_VEL_WRT_EARTH: measured with respect to Earth,
expressed in J2000 Earth Mean
Equator and Vernal Equinox
coordinates corrected for light
time and stellar aberration.
DFMI_VELSUN_ANGLE: This is the angular separation
between the DFMI Sensor Unit
Normal and the velocity vector of
the spacecraft which is measured
with respect to the sun.
DFMI_VELWILD2_ANGLE: This is the angular separation
between the DFMI Sensor Unit
Normal and the velocity vector of
the spacecraft which is measured
with respect to the comet Wild 2.
DFMI_VELEARTH_ANGLE: This is the angular separation
between the DFMI Sensor Unit
Normal and the velocity vector of
the spacecraft which is measured
with respect to the Earth.
DFMI_VELISP_ANGLE: This is the angular separation
between the DFMI Sensor Unit
Normal and the velocity vector of
the spacecraft which is measured
with respect to the Interstellar
Contact Information:
====================
For any questions regarding the data format of the archive,
contact:
Howard Taylor
Applied Coherent Technology Corp
112 Elden Street, Suite K
Herndon, VA 20170
(818) 354-5401
taylor@actgate.com
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