This table contains Galileo DDS detector responses and derived quantities as well as spacecraft geometry information for reliable impacts. See Gruen et al. (1995b) and Krueger et al. (1999b) for more information.
START_TIME = 1989-12-31T10:08 STOP_TIME = 1992-12-28T15:47 PRODUCT_CREATION_TIME = 1996-03-06 /* Peer Review Date */ ROWS = 13429 COLUMNS = 36 RECORD_FORMAT = "(i6,1x,i6,1x,a14,1x,i3,1x,f12.4,1x,i1,1x, i1,1x,i3,1x,i2,1x,i2,1x,i2,1x,i2,1x,i2,1x,i2,1x,i1,1x,i1,1x,i2,1x,i2,1x, i1,1x,i1,1x,i1,1x,i1,1x,i1,1x,a1,1x,f7.5,1x,f5.1,1x,f5.1,1x,f7.5,1x,f7.5, 1x,i3,1x,i3,1x,i3,1x,f4.1,1x,f4.1,1x,e8.2,1x,f6.1)"
IMPACT SEQUENCE NUMBER -
The number associated with a reliable impact
with 1 being the first impact recorded and n being the n'th impact
recorded.
EVENT SEQUENCE NUMBER -
The number associated with an event in
the file, GALDEVNT.TAB, with 1 being the first event recorded
and n being the n'th event recorded.
EVENT TIME -
The time of the event given in year,
day of year, hours and minutes in the general form: yyyy-dddThh:mm.
See Confidence Level Note, Impact Times.
TIME ERROR VALUE -
The uncertainty of the event time (TEV).
A value of zero corresponds to an uncertainty of 2/3 seconds.
See Confidence Level Note, Time Error Value.
JULIAN DATE -
The full Julian date of the event.
EVENT CLASS -
CLASS (CLN) is the event category class
which is represented by a single integer ranging from 0 to 3. Class
0 includes all events which are not categorized in a higher class. For
classes 1 through 3 the measured parameters and their relation to
each other are increasingly restricted, so that CLASS = 3 generally
represents dust impact events only. CLASS is determined from ION AMPLITUDE
(IA), CHANNELTRON AMPLITUDE (CA), ELECTRON AMPLITUDE (EA), ELECTRON RISE
TIME (ET), ION RISE TIME (IT), ION CHANNELTRON COINCIDENCE (IC), ELECTRON
ION COINCIDENCE (EI), and noise counters of the electron collector (EN),
ion collector (IN), and the channeltron (CN).
ION AMPLITUDE RANGE -
The ION AMPLITUDE RANGE (AR) is the
classification of the ION AMPLITUDE value into one of 6 subranges.
Each subrange is denoted by an integer between the values of 1 and
6. The six amplitude sub-ranges correspond roughly to a decade of
measured electronic charge.
SECTOR -
The angular orientation of the
sensor axis about the spacecraft spin axis at the time of each event,
measured in the plane perpendicular to the spin axis of Galileo.
The angle is defined to be zero when the sensor axis crosses the ecliptic
plane toward ecliptic north. Its value increases clockwise when the
spacecraft is seen from the Earth. SECTOR is an 8-bit counter having
integer values between 0 and 255, and is converted to degrees through
scaling by 1.40625. See Confidence Level Note, Sector.
ION AMPLITUDE CODE -
An integer code (IA) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the maximum observed signal associated with a single event
measured by the ion collector. Conversions to units of coulomb are
given in GALDCODE.TAB. Increasing values indicate increasing amplitude.
Eight digitization steps cover about one decade in charge. Steps 32
through 47 are not used. Apparent gaps in the otherwise uniform amplitude
sequences occur at steps 16 and 48. These are caused by transitions
between different amplifiers.
ELECTRON AMPLITUDE CODE -
An integer code (EA) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the maximum observed signal associated with a single event
measured by the electron collector. Conversions to units of coulomb are
given in GALDCODE.TAB. Increasing values indicate increasing amplitude.
Eight digitization steps cover about one decade in charge. Steps 32
through 47 are not used. Apparent gaps in the otherwise uniform amplitude
sequences occur at steps 16 and 48. These are caused by transitions
between different amplifiers.
CHANNELTRON AMPLITUDE CODE -
An integer code (CA) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the maximum observed signal associated with a single event
measured by the channeltron. Conversions to units of coulomb are given
in GALDCODE.TAB. Increasing values indicate increasing amplitude.
ION RISE TIME CODE -
An integer code (IT) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the rise time associated with a single event measured by the
ion collector. Conversions to units of micro-seconds are given in
GALDCODE.TAB. Increasing values indicate increasing rise time.
ELECTRON RISE TIME CODE -
An integer code (ET) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the rise time associated with a single event measured by the
electron collector. Conversions to units of micro-seconds are given in
GALDCODE.TAB. Increasing values indicate increasing rise time.
ELECTRON ION TIME CODE -
An integer code (EIT) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the difference in time between the start of the electron
signal and the start of the ion signal which are associated with a single
event. Conversions to units of micro-seconds are given in GALDCODE.TAB.
Increasing values indicate an increase in the value of the start time of
the electron signal minus the start time of the ion signal.
ELECTRON ION COINCIDENCE -
This is an indicator of coincidence
of measured negative and positive charge PULSES (EIC). The difference in
times between the achievement of threshold values for the measured
negative and positive charges is determined. If that difference is
less than 200 nanoseconds, this variable is set to 1, and to 0 otherwise.
ION CHANNELTRON COINCIDENCE -
This is an indicator of coincidence
of measured channeltron and positive charge pulses (ICC). The difference
in times between the achievement of threshold values for the measured
channeltron and positive charges is determined. If that difference is
less than 200 nanoseconds, this variable is set to 1, and to 0 otherwise.
See Confidence Level Note, Ion Channeltron Coincidence.
ENTRANCE GRID AMPLITUDE CODE -
An integer code (PA) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the maximum observed signal associated with a single event
measured by the entrance grid. Conversions to units of coulomb are
given in GALDCODE.TAB. Increasing values indicate increasing amplitudes.
See Confidence Level Note, Entrance Grid Amplitude Code.
ENTRANCE GRID RISE TIME CODE -
An integer code (PET) corresponding to the
logarithmic mean of the minimum and maximum range of the bin within
which falls the time difference between the entrance grid pulse and the
negative charge (electron collector) signal associated with a single event. Conversions to units of
micro-seconds are given in GALDCODE.TAB. Increasing values indicate
increasing rise times.
EVENT DEFINITION -
The EVENT DEFINITION (EVD) indicates
which channels initiates a measuring cycle. The x in each column
indicates the channels for which threshold values must be exceeded.
ION COLLECTOR THRESHOLD -
Code (ICP) corresponding to the
threshold set for the positive ion charge impulse (Q_I) arising from an
event.
ELECTRON COLLECTOR THRESHOLD -
Code (ECP) corresponding to the
threshold set for the electron charge impulse (Q_E) arising from an
event.
CHANNELTRON THRESHOLD -
Code (CCP) corresponding to the
threshold set for the channeltron charge impulse (Q_C) arising from an
event.
ENTRANCE GRID THRESHOLD -
Code (PCP) corresponding to the
threshold set for the entrance grid charge pulse(Q_P) at the time of
event separately for positively and negatively charged particles.
CHANNELTRON VOLTAGE LEVEL -
Code (HV) corresponding to the
channeltron high voltage level(HV) set at the time of an event with
integers representing fixed voltage differences.
See Confidence Level Note, Channeltron Voltage Level.
SPACECRAFT-SUN DISTANCE -
The distance from the spacecraft to
the sun.
ECLIPTIC LONGITUDE -
The heliocentric ecliptic longitude
(Equinox 1950.0) of the spacecraft.
ECLIPTIC LATITUDE -
The heliocentric ecliptic latitude
(Equinox 1950.0) of the spacecraft.
SPACECRAFT-EARTH DISTANCE -
The distance from the spacecraft to Earth.
See Confidence Level Note, Spacecraft Earth Distance.
SPACECRAFT-JUPITER DISTANCE -
The distance from the spacecraft to
Jupiter.
ROTATION ANGLE -
The angular orientation of the
sensor axis about the spacecraft spin axis at the time of each event.
It is measured in the plane perpendicular to the spin axis of Galileo.
The angle is defined to be zero when the sensor axis points closest
to the ecliptic north and it increases clockwise when the spacecraft is
seen from the Earth. It is related to SECTOR through the relation:
ROTATION ANGLE = 90 - SECTOR (where SECTOR is converted to degrees).
DETECTOR ECLIPTIC LONGITUDE -
The spacecraft-centered ecliptic longitude (Equinox 1950.0)
of the sensor axis.
DETECTOR ECLIPTIC LATITUDE -
The spacecraft-centered ecliptic latitude (Equinox 1950.0)
of the sensor axis.
PARTICLE SPEED -
The mean impact speed of the particle.
When no speed can be determined, the value is set to 99.9
See Data Reduction, Impact Speed, and Confidence Level Note, Impact Speed.
PARTICLE SPEED ERROR FACTOR -
An upper and lower estimate of impactor
speed is obtained by multiplying and dividing, respectively, the mean
particle speed by this factor. When no speed (hence error factor) can be
determined, the value of this factor is set to 99.9.
See Data Reduction, Impact Speed Error Factor,
and Confidence Level Note, Impact Speed.
PARTICLE MASS -
The mean particle mass. When the particle
speed is not determined, the mass is not determined and is set to 0.e0.
See Data Reduction, Impactor Mass.
PARTICLE MASS ERROR FACTOR -
An upper and lower estimate of impactor
mass is obtained by multiplying and dividing, respectively, the mean
particle mass by this factor. When the speed is not determined, neither is
the mass, and this factor is set to 9999.9. See Data Reduction, Impactor Mass Error Factor.
On board qualification scheme.
***** Before July 14, 1994: *****
-------------------------------------------------------------------
Parameters: | CLN=0 | CLN=1 | CLN=2 | CLN=3
-------------------------------------------------------------------
IA | IA > 0 | IA > 0 | IA > 0 | IA > 0
-------------| or | or |---------------------------------
EA | EA > 0 | EA > 0 | EA > 0 | EA > 0
-------------| or |-------------------------------------------
CA | CA > 0 | CA > 0 | CA > 0 | CA > 0
-------------------------------------------------------------------
ET | | | 1 <= ET <= 15 | 1 <= ET <= 15
-------------------------------------------------------------------
IT | | | 1 <= IT <= 15 | 1 <= IT <= 15
-------------------------------------------------------------------
EIC | | | EIC = 0 | EIC = 0
-------------------------------------------------------------------
ICC | | | ICC = 1 | ICC = 1
-------------------------------------------------------------------
Noise counter| | | |
of: | | | |
EN | | | | EN <= 8
IN | | | | IN <= 2
CN | | | | CN <= 8
-------------------------------------------------------------------
***** After July 14, 1994: *****
Note: Classes 1 and 2 are divided into two different subclasses which
are mutually exclusive.
------------------------------------------------------------------------
Parameters: | CLN=0 | CLN=1 | CLN=2 | CLN=3
------------------------------------------------------------------------
IA | IA>0 | IA>0 | IA>0 | IA>0 | IA>0 | IA>0
-------------| or |--------|------|------------|--------|-----------
EA | EA>0 | EA>0 | | EA>0 | | EA>0
-------------| or |--------|------|------------|--------|-----------
CA | CA>0 | | CA>0 | | CA>0 | CA>0
-------------|-------|--------|------|------------|--------|-----------
ET | | | | | | 1<=ET<=15
-------------|-------|--------|------|------------|--------|-----------
IT | | | | | | 1<=IT<=15
-------------|-------|--------|------|------------|--------|-----------
EIC | | EIC=1 | | EIC=0 | | EIC=0
-------------|-------|--------|------|------------|--------|-----------
ICC | | | | | ICC=1 | ICC=1
-------------|-------|--------|------|------------|--------|-----------
| | EIT=0 | | | |
EIT | | or | | 3<=EIT<=15 | | 3<=EIT<=15
| | EIT=15 | | | |
-------------|-------|--------|------|------------|--------|-----------
Noise counter| | | | | |
of: | | | | | |
EN | | | | EN<=8 | | EN<=8
IN | | | | IN<=14 | | IN<=2
CN | | | | | CN<=14 | CN<=2
------------------------------------------------------------------------
AR | ION AMPLITUDE
----+--------------
1 | 0 - 7
2 | 8 - 15
3 | 16 - 23
4 | 24 - 32
5 | 48 - 55
6 | 56 - 60
EVD|Q_I Q_E Q_C
---+-----------
0 | x x x
1 | x x
2 | x x
3 | x
4 | x x
5 | x
6 | x
ICP|Q_I (coulomb)
---+----------------
0 | 1.0E-14
1 | 2.6E-14
2 | 5.8E-14
3 | 1.5E-13
ECP|Q_E (coulomb)
---+----------------
0 | -9.8E-15
1 | -2.4E-14
2 | -5.5E-14
3 | -1.4E-13
CCP|Q_C (coulomb)
---+----------------
0 | -1.8E-13
1 | -2.4E-13
2 | -5.2E-13
3 | -1.2E-12
PCP|Q_P (positive) (coulomb)|Q_P (negative) (coulomb)
---+------------------------+------------------------
0 | 9.4E-15 | -1.8E-14
1 | 2.3E-14 | -3.8E-14
2 | 5.0E-13 | -7.3E-14
3 | 1.2E-13 | -1.5E-13
HV|Voltage(Volts)
--+-------
?| UNKN
X| OFF
0| 200
1| 900
2| 1020
3| 1140
4| 1250