Data Set Information
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DATA_SET_NAME |
CASSINI ORBITER MAG CALIBRATED SUMMARY 1 MINUTE AVERAGE V1.0
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DATA_SET_ID |
CO-E/SW/J/S-MAG-4-SUMM-1MINAVG-V1.0
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NSSDC_DATA_SET_ID |
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DATA_SET_TERSE_DESCRIPTION |
This data set contains calibrated 1 minute averaged Cassini
magnetometer data, for the entire Cassini mission.
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DATA_SET_DESCRIPTION |
Data Set Overview
=================
This data set contains magnetic-field data acquired during the
cruise and tour phases of the Cassini mission to Saturn.
On 16 August, 1999 two days before the spacecraft commenced Earth
swingby, the magnetometer boom was unfurled into its extended
position; a configuration it maintained for the remainder of the
mission. Magnetic-field data acquired prior to boom deployment are
limited and are significantly affected by spacecraft noise. These
data are of no scientific value and, consequently, do not form part
of this data set.
Cassini carried two magnetometers: a fluxgate magnetometer (FGM)
and a vector-helium magnetometer capable of operating in both
vector and scalar mode (V/SHM). This data set contains calibrated,
and averaged magnetic-field data recorded by the FGM instrument.
The data are provided in 1 minute averages. The 1 minute data are
provided in year files. The data are provided in RTN coordinates
throughout the mission. After arrival at Saturn, the Saturn-centered
KRTP, KSO, and KSM coordinates are also provided. Earth-centered,
and Jupiter-centered coordinates are provided for the flybys of
those two planets. All data files are ASCII.
These data were calibrated, and rotated into geophysical coordinates
by the Cassini MAG team at Imperial College (IC), and provided to
the PDS/PPI node via the Cassini MAG team Co-I at UCLA. In other
words these data use the same calibration as the data routinely
delivered to the Cassini MAG team. The data were also averaged at
IC. The data were reformatted into their current ASCII format,
add trajectory information was added at PDS/PPI.
Processing
==========
Coordinate Systems
==================
The coordinate systems in which the data are provided in vary by
mission phase, and are designed to support both solar wind and
planetary magnetospheric studies.
Solar Wind Coordinates
----------------------
Radial-Tangential-Normal Coordinates (RTN)
------------------------------------------
RTN coordinates consist of R (radial component, Sun to the
spacecraft), T (tangential component, parallel to the Solar
Equatorial plane and perpendicular to R), and N (normal component,
completes right handed set).
Saturn-Centered Coordinates
---------------------------
Kronocentric body-fixed, J2000 spherical Coordinates (KRTP)
-----------------------------------------------------------
KRTP magnetic field vector components form the standard right-handed
spherical triad (R, Theta, Phi) for a planet-centered system.
Namely, R is radial (along the line from the center of Saturn to the
center of the spacecraft), and positive away from Saturn. Phi, the
azimuthal component, is parallel to the Kronographic equator (Omega
x R) and positive in the direction of corotation. Theta, the
'southward' component, completes the right-handed set.
Kronocentric Solar Magnetospheric Coordinates (KSM)
---------------------------------------------------
KSM is a cartesian Saturn-center coordinate system where X points
from Saturn to the Sun, the X-Z plane contains Saturn's centered
magnetic dipole axis, M, and Y completes right handed set.
Kronocentric Solar Orbital Coordinates (KSO)
--------------------------------------------
KSO is a cartesian Saturn-centered coordinate system where X points
from Saturn to the Sun, Z is parallel to Saturn's orbital plane
upward normal, and Y completes the right handed set.
Earth-Centered Coordinates
--------------------------
Jupiter-Centered Coordinates
----------------------------
Jovicentric Body-Fixed (IAU_JUPITER) Coordinates (J3)
-----------------------------------------------------
J3 is a body-fixed Jovicentric cartesian coordinate system
consistent with the IAU 1997 definition of the System 3 prime
meridian where X is in the Jovian equatorial plane, along S3
1997 Prime Meridian, Z is parallel to the Jovian spin axis,
and Y completes right-handed set.
Jovicentric Body-Fixed Magnetospheric Coordinates (JMXYZ)
---------------------------------------------------------
JMAG XYZ is a body-fixed Jovicentric cartesian coordinate system
where X is in the plane containing Z and the S3 1997 Prime Meridian,
Z is the Jupiter magnetic dipole, and Y completes right handed set.
SPICE
=====
The data product labels associated with the data set include the name of
a SPICE metakerenls which contains a list of the SPICE kernels that were
used in calibrating the magnetic-field data, coverting them to physical
coordinates, and generating the associated trajectory information.
Copies of these metakernels are included in the GEOMETRY directory of
the archive volume on which the data are located. While the SPICE
kernels themselves are not part of this data set, they are archived at
the PDS-NAIF node on the volume cosp_1000. Note that the SPICE kernels
listed in the metakernels may be uniquely identified by their file name.
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DATA_SET_RELEASE_DATE |
2017-10-10T00:00:00.000Z
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START_TIME |
2000-01-20T02:28:30.000Z
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STOP_TIME |
2000-12-31T05:43:30.000Z
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MISSION_NAME |
CASSINI-HUYGENS
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MISSION_START_DATE |
1997-10-15T12:00:00.000Z
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MISSION_STOP_DATE |
2017-09-15T12:00:00.000Z
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TARGET_NAME |
EARTH
SATURN
JUPITER
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TARGET_TYPE |
PLANET
PLANET
PLANET
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INSTRUMENT_HOST_ID |
CO
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INSTRUMENT_NAME |
DUAL TECHNIQUE MAGNETOMETER
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INSTRUMENT_ID |
MAG
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INSTRUMENT_TYPE |
MAGNETOMETER
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NODE_NAME |
Planetary Plasma Interactions
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ARCHIVE_STATUS |
SUPERSEDED
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CONFIDENCE_LEVEL_NOTE |
Product Versions
================
PRODUCT_VERSION_ID 1 data were calibrated at the PDS/PPI node at
UCLA using software (CAL02), and calibration data provided by the
Cassini MAG team. The process used the same calibration data that
was provided with the Raw Magnetometer data archive (Data Set ID:
CO-E/SW/J/S-MAG-2-REDR-RAW-DATA-V1.0). The data were then rotated
into geophysical coordinates using MAG team additonal MAG team
provided code (TRANSCAL) and spice kernels obtained from NAIF.
Additional processing, including averaging, reformatting to ASCII,
and the addition of trajectory to the 1 minute data was performed
using code developed at PDS/PPI.
PRODUCT_VERSION_ID 2 data were calibrated, and rotated into
geophysical coordinates by the Cassini MAG team at Imperial
College, and provided to the PDS/PPI node via the MAG team Co-I at
UCLA. The 1 minute data were also averaged at IC. Averaging for the
1 second data was performed at PDS/PPI. The data were reformatted
at PDS/PPI to match the format used for the version 1 data.
PRODUCT_VERSION_ID 3 data were processed following the same
procedure that was followed for the version 2 data. However,
subsequent to the release of the version 2 data it was discovered
that the coordinate system trasformation for some of those data had
been performed using predict SPICE kernels, rather than
reconstructions. The version 3 were reprocessed using reconstructed
ephemeris kernels for all of the data.
PRODUCT_VERSION_ID 4 data were processed following the same
procedure that was followed for the version 2 and 3 data. These
data, however, were processed using only reconstructed SPK's to
generate the trajectory data, thus correcting the errors which
were present in the version 3 data. The MAG data do not differ
between versions 3 and 4.
PRODUCT_VERSION_ID 5 data were processed following the same
procedure that was followed for the version 3 and 4 data. These data
include corrections to the NPTS column data values, and some updates to
the label files.
PRODUCT_VERSION_ID 6 for RTN data files - The DATA/ *_FGM_RTN_1M.TAB
files, Version 5, and older versions, had assigned a width to the Sun
to Spacecraft distance column (RANGE) that was insufficient to
accommodate values over 10 AU. This resulted in inconsistent record
structures and lengths. The version 6 RTN files correct this error by
allocating an additional byte to the RANGE column width and adjusting
the start position of the subsequent columns accordingly.
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CITATION_DESCRIPTION |
Dougherty, M.K., S. Kellock, A.P. Slootweg, N. Achilleos, S.P. Joy,
and J.N. Mafi, CASSINI ORBITER MAG CALIBRATED SUMMARY AVERAGED V1.0,
CO-E/SW/J/S-MAG-4-SUMM-AVG1MIN-V1.0, NASA Planetary Data System,
2006
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ABSTRACT_TEXT |
This data set contains calibrated 1 minute averaged Cassini
magnetometer data, for the entire Cassini mission. These data are
provided in Kronographic (KRTP, KSO, KSM) coordinates at Saturn,
Geographic coordinates (GSE, GSM) for the Earth flyby, Jovigraphic
coordinates for the Jupiter flyby, and RTN coordinates for the entire
mission. These data were calibrated, converted to physical coordinates
and averaged to 1 minute by the Cassini MAG team at Imperial College.
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PRODUCER_FULL_NAME |
JOSEPH N. MAFI
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SEARCH/ACCESS DATA |
Planetary Plasma Interactions Website
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