Cassini Magnetometer Calibrated Bundle
Cassini MAG Calibrated 1 Sec. Avg. Data in RTN Coords.
Collection Description
PDS3_DATA_SET_ID = CO-E/SW/J/S-MAG-4-SUMM-1SECAVG-V2.0
ORIGINAL_DATA_SET_RELEASE_DATE = 2017-10-09
Version 2.0 Release Date = 2019-06-17
START_TIME = 1998-12-30T11:38:33.005
STOP_TIME = 2017-09-12T05:27:18.5
PRODUCER_FULL_NAME = JOSEPH N. MAFI
Data Collection Description
Data Collection Overview
========================
This data collection 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 collection.
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 collection contains
calibrated, and averaged magnetic-field data recorded by the FGM
instrument. The data are provided in both 1 second. The 1 second
averaged data files span 1 quarter of year prior to arrival at Saturn,
and 1 Saturn orbit following arrival at Saturn. The data are provided
in RTN coordinates throughout the mission. 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. Averaging for the 1 second data
was performed at the PDS-PPI Node.
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).
SPICE
=====
The data product labels associated with the data collection include a
list of the SPICE kernels that were used in calibrating the associated
data, and coverting them to physical coordinates. While the SPICE
kernels used are not part of this data collection, these kernels are
archived at the PDS-NAIF node on the volume cosp_1000. Note that the
SPICE kernels listed in each of the product labels may be uniquely
identified by their file name.
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.
The data were then averaged, and reformatted to ASCII 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. Averaging to 1 second was performed at PDS/PPI (UCLA). The
data were then reformatted at PDS/PPI to match the format used for
the version 1 data.
PRODUCT_VERSION_ID 3 have followed the same path as the version 2
data, however, the data have been recalibrated.
PRODUCT_VERSION_ID 4 data were processed following the same
procedure that was followed for the version 2 data. However,
previously undetected mis-time tagged data which were present in
the full-resolution data were removed prior to averaging the data
to 1 second. More details on the timing errors are provided in the
confidence level note (below).
PRODUCT_VERSION_ID 5 data were processed following the same
procedure that was followed for the version 4 data, including the
removal of mis-timed data before averaging. In addition, version 5
products have been modified to satisfy liens set in the PDS peer
review. Including a change in record formatting, and changes to
the PDS labels.
PRODUCT_VERSION_ID 6 data were processed using an updated calibration
that was produced using data from the Cassini Proximal Orbits.
References
==========
Asmar, S.W., and N.A. Renzetti, The Deep Space Network as an Instrument
for Radio Science Research, Jet Propulsion Laboratory Publication
80-93, Rev.1, 15 April 1993.
Cassini Mission Plan, Revision N (PD 699-100), JPL Document D-5564, Jet
Propulsion Laboratory, Pasadena, CA, 2002.
Dougherty, M.K., S. Kellock, D.J. Southwood, A. Balogh, E.J. Smith,
B.T. Tsurutani, B. Gerlach, K.H. Glassmeier, F. Gleim, C.T.
Russell, G. Erdos, F.M. Neubauer, and S.W.H. Cowley, The Cassini
Magnetic Field Investigation, Space Science Reviews, Vol. 114, Nos.
1-4, pp. 331-383, September 2004
Kellock, S., P. Austin, A. Balogh, B. Gerlach, R. Marquedant, G.
Musmann, E. Smith, D. Southwood and S. Szalai, Cassini dual
technique magnetometer instrument (MAG), Proc. SPIE, Denver,
Colorado, 2803, 141, 1996.
Smith, E.J., M.K. Dougherty, C.T. Russell, and D.J. Southwood, Scalar
helium magnetometer observations at Cassini Earth swing-by, J.
Geophys. Res., 106, 30129, 2001.
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