PDS_VERSION_ID = PDS3
LABEL_REVISION_NOTE = "
1997, K. Ackerson, initial draft;
2000-03-15, K. Ackerson, major revision;
2000-03-16, M. Sharlow, added new PDS keywords;
2003-05-02, B. Harris, added note regarding time tags;
2003-06-25, S. Joy, minor revisions, added targets, terse description;
2003-08-18, S. Joy, minor revisions requested at peer review;"
OBJECT = DATA_SET
DATA_SET_ID = "GO-J-PLS-3-RDR-FULLRES-V1.0"
OBJECT = DATA_SET_INFORMATION
DATA_SET_NAME = "
GALILEO JUPITER RDR FULL RESOLUTION PLASMA DATA V1.0"
DATA_SET_COLLECTION_MEMBER_FLG = N
START_TIME = 1995-12-07T15:30
STOP_TIME = 2003-09-21T18:45
DATA_SET_RELEASE_DATE = 2003-11-21
PRODUCER_FULL_NAME = "DR. KENT ACKERSON"
DETAILED_CATALOG_FLAG = N
ARCHIVE_STATUS = "LOCALLY ARCHIVED"
DATA_OBJECT_TYPE = "TABLE"
CITATION_DESC = "Frank, L.A., Paterson, W.R.,
Ackerson, K.L., GALILEO JUPITER RDR FULL RESOLUTION PLASMA DATA V1.0,
GO-J-PLS-3-RDR-FULLRES-V1.0, NASA Planetary Data System, 2000."
ABSTRACT_DESC = "
This data set contains raw data from the Plasma Science instrument
(PLS) on the Galileo spacecraft for all Jupiter orbits. These data
have been reformatted into ASCII tables to facilitate data
processing and analysis."
DATA_SET_TERSE_DESC = "
This data set contains raw data from the Plasma Science instrument
(PLS) on the Galileo spacecraft for all Jupiter orbits. These data
have been reformatted into ASCII tables to facilitate data
processing and analysis."
DATA_SET_DESC = "
Overview:
=========
This data set contains data from the Plasma Science instrument
(PLS) onboard the Galileo spacecraft during the Jupiter orbital
operations phase (December 1995 to end of mission). These data have
been edited and reformatted from the raw telemetry packets into a
simple ASCII tabular structure to facilitate processing and analysis.
Parameters:
===========
This data set includes both high time resolution (LPW) data recorded
during targeted encounters and real-time science (RTS) data acquired
during the magnetospheric survey when telemetry was available. The
Plasma instrument can collect either RTS data or LPW data but not
both simultaneously.
The basic data set parameters are the detector count rates in units
of counts per second. Data are provided at the full instrument
sampling rate in all sampling parameters (time, detector, E/Q, M/Q).
The instrument has twenty (20) detectors (seven ion, seven electron,
six mass spectrometer) and can sample E/Q or M/Q (mass spectrometer
detectors only) in sixty-four (64) steps for each detector.
Processing:
===========
The final instrument packet files (IPF's) have been processed to
decommutate the PLS telemetry into individual instrument modes. Each mode
generally covers one spacecraft rotation and contains a number of energy
spectra (or mass spectra) at a number of angles.
In LPW mode an instrument cycle spans an interval of 4 RIM's (242.67
seconds). During this interval the instrument collects approximately
28 individual modes of data. In RTS operation the cycle is different,
and longer, due to the severely reduced telemetry rates. The
energies, accumulation times, and sectoring schemes all vary from
mode to mode, as with the LPW data.
A major accomplishment of the RDR processing is to recast the PLS
data in a format that is independent of the details of the operating
modes. The resulting RDR data records are much easier to use.
The PLS telemetry system is sensitive to data gaps. Repairing data
due to embedded data gaps cannot be automated. Consequently
measurements with gaps in the middle of an individual modes are not
included in the RDR file. Fortunately, such gaps occurred
infrequently. The recovery of LPW data was generally good. Multiple
playbacks were made on each LPW recording to fill gaps.
Please refer to the calibration document (CALIB.TXT) contained on the
PDS archive volume for a discussion of pitfalls and problems in using
the RDR files. This document is located on the PDS archive volumes in
the DOCUMENT/PLS directory.
Ancillary Data:
===============
Several ancillary files are provided with these data: calibration
tables, a calibration document, and a spacecraft events file.
Calibration:
PLSCALIB.TXT Describes the calibration algorithm and pitfalls.
PLS_DETS.TAB maps detector numbers to detector names/functions
E_STEP_1.TAB E-steps for electron detectors 14,16,18, and 20.
E_STEP_2.TAB E-steps for ion dets 3,5,9,11 and mass spec dets 6,7
E_STEP_3.TAB E-steps for electron detectors 15,17, and 19.
E_STEP_4.TAB E-steps for ion dets 4,8,10 and mass spec dets
1,2,12,13 M_STEP_1.TAB M-steps for the mass spectrometer channels
SECTOR.TAB AACS sector angles
CALIB_1.TAB Calibration factors to convert count rates to
differential flux for electron detectors 14,16,18,
and 20 CALIB_2.TAB Calibration factors to convert
count rates to differential flux for ion detectors
3,5,9,11 and mass spec detectors 6 and 7.
CALIB_3.TAB Calibration factors to convert count rates to
differential flux for electron detectors 15,17, and
19. CALIB_4.TAB Calibration factors to convert
count rates to differential flux for ion detectors
4,8,10 and mass spec detectors 1,2,12 and 13.
Spacecraft Events:
xxx_SEF.TXT A time ordered file extracted from the As-Run
Spacecraft Events Files (ARSEF) that provides the timing of events
that are significant to the plasma experiment. These events include
whether or not the instrument is 'on', which type of data are being
acquired (RTS or LPW), the time of thruster firings, etc. The 'xxx'
in the file name is the orbit name (i.e. G01 for orbit Ganymede 1).
Coordinate System:
==================
Data are provided in PLS instrument coordinates. Please refer to the
instrument description paper [FRANKETAL1992] for a description of the
instrument mounting, detector fields of view, and spin phase
sectoring. See also the SECTOR.TAB file in the ancillary data files.
Software:
=========
There is no software provided with this archive.
Media/Format:
=============
These data are archived on either CDROM or DVDROM media. The data
files are stored in a simple ASCII table form that is described by a
detached PDS label (Table Object). Each table has the following
structure:
Col# Name Format Description
-----------------------------------------------------------------------
1 Time A24 Spacecraft event time (UTC)
2 SCLK A11 Spacecraft clock counter (RIM:mf)
3 Rate 1PE8.2 Count rate (counts/sec)
4 DetId I2 Detector Id (1-20)
5 E-Step I2 E/Q analyzer step (0-63)
6 M-Step I2 M/Q analyzer step (0-63)
7 Sector I3 AACS rotor spin angle (0-255 =2 PI).
8 Sample I2 Sample number
9 Accum F6.4 Accumulation time in seconds "
CONFIDENCE_LEVEL_NOTE = "
Data Coverage/Quality:
======================
This data set contains gaps in coverage. Many of these gaps were
planned (insufficient telemetry coverage to provide continuous data)
and others were not (telemetry dropouts, station outages, etc.).
Some files may not be completely continuous in time. This is a result
of how the data is transmitted and received:
'The PLS instrument has two analyzers: A and B. Each analyzer has its own
sensors, high voltage supplies, analyzer plates, and data paths. The two
analyzers normally start a spin-mode at the same time. And they normally
end a spin-mode at the same time. Both data streams are buffered
internally by the PLS data system and sent out to the spacecraft in a
packetized telemetry scheme. Generally, the two streams are interleaved
on a minor-frame-by-minor-frame basis, but if one analyzer does not have
data ready and the other does then the telemetry that is ready is sent.
(Note that the two analyzers have different numbers of sensors and create
different quantities of data.)
On the ground, the PLS telemetry stream is decommutated and separated into
A and B data-sets for each spin-mode. The time tag attached to each
A-data-set and each B-data-set is the time of the first telemetry packet
containing some of that data. As soon as a complete data set has been
decommutated on the ground it is written to the output file. And this is
the key to understanding what is happening. Sometimes the first data-set
to appear in the telemetry stream is also the first one to be completed.
And sometimes the first data-set to appear in the telemetry is the last to
be completed. It is essentially a random thing.
It is crucial to note that PLS takes all of its data in a spin-
synchronized fashion, not in a SCLK-synchronized fashion. We went to
great pains to ensure that the data were obtained in well-defined spin
sectors and in repeatable directions. Differences of a couple of
minor-frames are not significant. The spin-phase angles are the
quantities of importance.' "
END_OBJECT = DATA_SET_INFORMATION
OBJECT = DATA_SET_TARGET
TARGET_NAME = JUPITER
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = IO
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = EUROPA
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = GANYMEDE
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_TARGET
TARGET_NAME = CALLISTO
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_HOST
INSTRUMENT_HOST_ID = GO
INSTRUMENT_ID = PLS
END_OBJECT = DATA_SET_HOST
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "FRANKETAL1992"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
END_OBJECT = DATA_SET
END