PDS_VERSION_ID = PDS3
LABEL_REVISION_NOTE = "
2015-12-11, D. Kazden - removed ARCHIVE_STATUS keyword;
2018-06-26, D. Kazden - updated STOP_TIME and DATA_SET_RELEASE_DATE;
2020-03-11, D. Kazden - updated ABSTRACT_DESC and CITATION_DESC;"
RECORD_TYPE = STREAM
OBJECT = DATA_SET
DATA_SET_ID = "CO-S-MIMI-4-INCA-CALIB-V1.0"
OBJECT = DATA_SET_INFORMATION
DATA_SET_NAME = "
CASSINI S MIMI INCA SENSOR CALIBRATED DATA V1.0"
DATA_SET_COLLECTION_MEMBER_FLG = N
START_TIME = 2004-01-01T00:00
STOP_TIME = 2017-09-15T10:28:13.242
DATA_SET_RELEASE_DATE = 2018-06-26
PRODUCER_FULL_NAME = "Martha B. Kusterer"
DETAILED_CATALOG_FLAG = N
DATA_OBJECT_TYPE = "SPREADSHEET"
DATA_SET_TERSE_DESC = "
This data set contains all of of the calibrated Saturn tour data for
the INCA sensor of the MIMI instrument aboard the Cassini spacecraft
for the Cassini mission. INCA stands for Imaging Neutral Camera."
ABSTRACT_DESC = "
The Ion and Neutral Camera (INCA) obtains remote images of the global
distribution of energetic ions for energies from 7 keV/nucleon to 8
MeV/nucleon, discriminated according to energy and mass species
(oxygen and hydrogen). To obtain the images, INCA measures the arrival
directions, energy and mass species of Energetic Neutral Atoms (ENA's)
using the relatively new technique of ENA imaging. INCA also can be
commanded to obtain very high sensitivity ion measurements, providing
the angular, energy and species distributions of in-situ O and H ions.
The Cassini Magnetospheric Imaging Instrument(MIMI) Imaging Neutral
Camera (INCA) calibrated data set includes all image data collected
from the MIMI Data Processing Unit during the Saturn tour. The
original data has been decommutated, decoded, calibrated and further
processed by software at the Applied Physics Laboratory (APL).
The calibrated image data is provided in three forms: an averaged
form where the original image N x N pixel images pixels intensity are
averaged to a single value for one species and time-of-flight (TOF)
combination, browse images which display rows and columns of images
for one species and TOF combination, and movies which display
averaged ENA image skymaps.
Calibration of INCA data has been described fully in the
Cassini/MIMI Data User Guide.
This data set should be among the first used by a user of any of the
MIMI INCA archive as it will lead one to information required to
search for more detailed or highly specialized features in the
original data."
CITATION_DESC = "Vandegriff J., Kusterer M.B., Mafi J.,
CO-S-MIMI-4-INCA-CALIB-V1.0, CASSINI S MIMI INCA SENSOR CALIBRATED
DATA V1.0NASA Planetary Data System, 2018."
DATA_SET_DESC = "
Data Set Overview
=================
The Ion and Neutral Camera (INCA) obtains remote images of the global
distribution of energetic ions for energies from 7 keV/nucleon to 8
MeV/nucleon, discriminated according to energy and mass species
(oxygen and hydrogen). To obtain the images, INCA measures the arrival
directions, energy and mass species of Energetic Neutral Atoms (ENA's)
using the relatively new technique of ENA imaging. INCA also can be
commanded to obtain very high sensitivity ion measurements, providing
the angular, energy and species distributions of in-situ O and H ions.
INCA image data are available in three different flavors, each flavor
being simultaneously generated. High spatial resolution images have a
larger number of pixels than other INCA images (up to 64 by 64), but
are available for fewer numbers of energies (usually just 2 energy
channels) and are taken at lower time resolution (one image every 4
sectors). High time resolution images are acquired each sector, but
have lower spatial resolution (usually 16 by 16 pixels)High
time-of-flight and mass resolution images are taken for 9 energy
ranges, but only every 4 sectors and with lower spatial resolution.
In neutral mode, which is used to obtain ENA images, alternate
collimator plates are charged to a high positive and negative voltage,
and these collimators sweep up ions and electrons entering the sensor.
Neutral atoms pass by the collimators through a slit. Alternately,
in ion mode, the collimators are not charged and the ions and
electrons pass into the detector.
The Cassini Magnetospheric Imaging Instrument(MIMI) Imaging Neutral
Camera (INCA) calibrated data set includes all image data collected
from the MIMI Data Processing Unit during the Saturn tour. The
original data has been decommutated, decoded, calibrated and further
processed by software at the Applied Physics Laboratory (APL).
The calibrated image data is provided in three forms: an averaged
form where the original image N x N pixel images pixels intensity are
averaged to a single value for one species and time-of-flight (TOF)
combination, browse images which display rows and columns of images
for one species and TOF combination, and movies which display
averaged ENA image skymaps.
Calibration of INCA data has been described fully in the
Cassini/MIMI Data User Guide. [VANDEGRIFFETAL2012]
This data set should be among the first used by a user of any of the
MIMI INCA archive as it will lead one to information required to
search for more detailed or highly specialized features in the
original data.
Parameters
==========
This data set comprises image pixel angle averages where the original
image N x N pixel image (where N is usually 16, 32 or 64) images pixels
intensity in are averaged to a single value for one species and TOF
combination. The value displayed is the image intensity in
counts/(centimeters squared*steradian*seconds*keV). These are called
angle averages since each image pixel has a particular look direction
out of the INCA instrument specified in azimuth and elevation. The
azimuth directions range from -45 to 45 degrees over the index range
0 to N, where N is the number of rows in the image. The elevation
values for each pixel range from 60 to -60 degrees (note: this is
backwards) over the index range 0 to N, where N is the number of
columns in the image. The pixel sizes are different depending on the
resolution of the image. Also note that the look direction angles for
each pixel are relative to the center of the INCA image, which may be
offset from its nominal center due to the way images are integrated on
the spacecraft. The registration of an INCA image against the sky in a
specific coordinate system involves proper interpretation of the offset
of the image center from its nominal direction. Full details describing
this process has been described fully in the Cassini/MIMI Data User
Guide. [VANDEGRIFFETAL2012]
The standard product ID's are:
MIMI_INCA_ANGAVE_S for the high spatial resolution angle averages
MIMI_INCA_ANGAVE_T for the high time resolution angle averages
MIMI_INCA_ANGAVE_M for the high mass TOF resolution angle averages
The data is organized in time by the spin of the spacecraft. When the
spacecraft is in staring mode then the MIMI DPU automatically creates
a virtual spin that divides the time collection periods into 16
sectors, 16 subsectors, and 16 microsectors and maintains a simple
organizational structure for characterizing the collection of the time
into time segments. When the spacecraft is spinning at a minimally
defined spin rate (adopted by the MIMI DPU) then the MIMI data is
automatically segregated into 16 sectors, 16 subsectors, and 16
microsectors. The INCA instrument collection times are then also
keyed to these values. The high spatial and high mass TOF image
averages are collected over 4 sectors and the high time resolution
image averages are collected over 1 sector.
Each file contains all the species and tof combination image angle
averages for one image resolution type. The resolution type, species
and TOF values are included in the parameter set.
In addition, this data set includes two types of browse products. One
product type is a PNG file containing three rows by N columns of
panels, where the bottom three rows are a continuation in time of the
top three rows. Each row contains spin averaged high spatial ENA
image skymaps (each one accumulated over four sectors), displayed for
one species and TOF combinations.
The other browse product type is a PNG file containing 1 up to 10
columns, high TOF browse ion thumbnail images displayed for seven
time-of-flight ranges (rows) for one species. The value
displayed is the log of the image intensity in
counts/(centimeters squared*steradian*seconds*keV).
The standard product ID's are:
MIMI_INCA_ENAIMG_HO for the ENA image skymaps
MIMI_INCA_IONANG_H for the ion hydrogen image thumbnails
MIMI_INCA_IONANG_O for the ion oxygen image thumbnails
The data set also contains MP4 movies which display averaged ENA image
skymaps (averaged over a variable, listed number of original on-board
images), for one species and TOF combination. The value displayed is
the log of the image intensity in
counts/(centimeters squared*steradian*seconds*keV).
The standard product ID's for the movies are
MIMI_INCA_ENAMV_SH0 for the high spatial resolution hydrogen low TOF movies
MIMI_INCA_ENAMV_SH7 for the high spatial resolution hydrogen high TOF movies
MIMI_INCA_ENAMV_S00 for the high spatial resolution oxygen low TOF movies
MIMI_INCA_ENAMV_S07 for the high spatial resolution oxygen high TOF movies
MIMI_INCA_ENAMV_TA0 for the high time resolution low TOF movies
MIMI_INCA_ENAMV_TA7 for the high time resolution low TOF movies
Processing
==========
Data in this data set were processed by the use of a number of
software programs which calibrate the images to differential intensity,
calculate the image angle averages, and display the images in either
the skymap or thumbnail display. The skymap and thumbnail images are
further processed by averaging the images together and displaying them
in rows and columns in browse products which reduces a days worth of
images to a few pages.
The display software makes use of the JPL Naif SPICE software which
contains algorithms to handle the various spacecraft rotation modes.
The MIMI team has created and maintain an analysis SPICE kernel set
which is available on the MIMI website. The many useful frames of
reference fordisplaying the INCA images with celestial bodies have
been included in the frame kernel. The SPICE frames used in the
products described here have been
explained in the coordinate system section below.
The skymaps are created by transforming the original image into
the following SPICE reference frame. The skymap frame is a dynamically
defined frame, XINCA_BORESIGHT_CENTERED, which is defined in the
Coordinate Systems section below.
Creation of the skymap and thumbnail image displays starts with the
calculation of each original image pixels look direction in aximuth
and elevation, based on the INCA boresight vector as well as the
azimuth and elevation offsets if applicable based on image collection
mode. The pixel matching the look direction in the skymap or thumbnail
display frame is calculated and the original image pixel intensity
value is loaded into the display frame pixel.
The thumbnail images are created by transforming the original images
into the INCA azimuth and elevation SPICE reference frame. The
definition of the thumbnail frame, CASSINI_MIMI_INCA_LL is described
in the Coordinate Systems section below. The elevation of the image
goes from -60 degrees at the bottom to 60 degrees at the top of the
image. The azimuth of the image goes from -45 degrees on the left
to 45 degrees on the right.
The MP4 movies are created using the skymap display software to output
consecutive ENA skymaps in time. The QuickTime software was used to
convert the PNG files into the movies. Typically the movies display
the INCA image data in the Saturn frame, XINCA_SATURN_CENTERED which
is described in the Coordinate System section below. The Titan frame,
XINCA_TITAN_CENTERED, is used to display the images for the Titan
flybys. It is also described below in the Coordinate System section.
The use of the Saturn centered or Titan centered frame improves the
continuity of movies because it reduces the effect of the
spacecraft motion on the movie.
Data
====
The MIMI INCA calibrated data set includes image angle averages,
browse images and movies. The image angle averages are an ASCII CSV
table. Each table contains variable length records for which the
fields are comma delimited.
INCA Image Angle Average Data
---------------------------
Fields include:
a purpose identifier where science data records are identified
with purpose = sci
starting and ending ephemeris times
Spin, sector, subsector (and for INCA Fine Rate (FRT) data
microsector)
SCLOCK and spin period that are used to derive the starting
ephemeris time
Notes regarding the SCLOCK value:
1. Only the SCLOCK major segment value is provided - MIMI
currently does not have access to the fine SCLOCK value
hence SCLOCK resolution is limited to +- 1/2 SCLOCK count
2. The SCLOCK is only available from telemetry at the
beginning of each spin. All other published SCLOCKS are
derived from the spin starting SCLOCK, the spin numbers
(for the current and next available spins), and the spin
period.
3. SCLOCK values are assumed to drive the value of the
ephemeris times and not vice-versa. All effort is made to
validate the published ephemeris times but since updates to
the Cassini SCLOCK kernel in SPICE can occur the values of
ephemeris time are only as accurate as the currently
published Cassini SCLOCK SPICE kernel.
Spacecraft staring mode where staring = 0 when spinning and 1
otherwise
INCA Images are organized as:
Type ID: a 4 byte word characterized as:
Byte 0 - Type: 0 = High Spatial, 1 = High Time,
2 = High m-TOF
Byte 1 - Charge: 0 = Neutral, 1 = Ion
Byte 2 - Species: 0 = H, 1 = He, 2 = CNO, 3 = Heavy,
4 = Other, 5 = All
Byte 3 - TOF: 0 = Low, 1-6 = Medium, 7 = High
Compression bits, Compression method, log compressed identifier
Theta and Phi offsets from spacecraft coordinates
The angle average and uncertainty are in units as image intensity in
counts/(centimeters squared*steradian*seconds*keV)
Each file contains all the species and tof combination image angle
averages for one image resolution type. The resolution type, species
and TOF values are included in the parameter set.
INCA Browse Images
------------------
The skymap browse images are in PNG files containing three rows by N
columns of panels, where the bottom three rows are a continuation
in time of the top three rows. Each row contains spin average
high spatial ENA image skymaps (each one accumulated over four
sectors), displayed for one species and TOF combinations.
Row one contains the high TOF hydrogen images, row two contains the low
TOF hydrogen images and row three contains the low TOF oxygen images.
The energy range for each TOF range is shown to the right of each row.
ENA images are collected when a high voltage is present on the INCA
collimator. The value displayed is the log of the image intensity which
is counts/(centimeters squared*steradian*seconds*keV). The color bars
for each row are independent and are determined by the minimum and
maximum pixels in that row (i.e., for the entire day).
Each original image was 64 x 64 pixels and was transformed into the
skymap frame, XINCA_BORESIGHT_CENTERED, which is described below in
the coordinate system section. One days data is contained in one to
three PNG files.
The thumbnail browse images are in PNG files containing 1 up to 10
columns, high TOF browse ion thumbnail images displayed
for seven TOF ranges (rows). Ion images are
collected when no voltage is present on the INCA collimator.
The image species include hydrogen at TOF ranges, where the energy
range for each TOF range is shown to the right of each row. The
value displayed is the log of the image intensity which is
counts/(centimeters squared*steradian*seconds*keV).
The color bars for each row are independent and are determined by the
minimum and maximum pixels in that row (i.e., for the entire day).
Each original image was 16 x 16 pixels and was transformed into
the INCA azimuth and elevation frame, CASSINI_MIMI_INCA_LL,
which is described below in the coordinate system section.
One days data is contained in one to twenty-four PNG files.
INCA ENA Movies
----------------
The INCA ENA movies consist of MP4 movies displaying averaged ENA
image skymaps (averaged over a variable, listed number of original
on-board images), for one species and TOF combination. ENA images are
collected when the voltage on the INCA collimator is high, typically
4kV. This excludes ions with E/q values less than ~180 to 200keV/q.
The value displayed is the log of the image intensity in
counts/(centimeters squared*steradian*seconds*keV).
The INCA ENA images are only produced for interesting features in the
INCA data and Titan flybys.
The color bar limits are set to a common minimum and maximum value
over the entire movie, chosen to bring out the salient features over
the time covered. These values typically change from one movie to the
next, based on activity levels and orbital position.
Each original image N x N pixel image (where N is usually 32 or 64)
was transformed into the Saturn frame, XINCA_SATURN_CENTERED, which is
described in the coordinate system section below. For Titan flybys, the
image was transformed into the Titan frame, XINCA_TITAN_CENTERED which
is described in the coordinate system section below.
Typically, though not always, the orbit of Titan, Dione and Rhea
(dotted line), Titan center (dot), and the axis for Saturn equatorial
system frame (white, centered at Saturn) are displayed. The definition
of the Saturn equatorial system frame, is described in the coordinate
system section below.
The pink axis (when present) is the Saturn Kilometric Radiation frame.
Due to the work of the RPWS team we now have several Saturn Kilometric
Radiation frames available for use.[1] The SKR frame is also described
below in the coordinate system section
Ancillary Data
==============
Coordinate System
=================
The MIMI INCA display software makes primary use of three SPICE frames
of reference which are used to display the images along with celestial
bodies. These SPICE frames are provided in their MIMI SPICE analysis
kernels set in the frame kernel.
The skymap frame, XINCA_BORESIGHT_CENTERED, is a dynamically defined
frame, defined as follows. The primary axis X is the INCA boresight
axis. The secondary Z axis is the Z axis of the IAU_SATURN frame. The
Y-axis completes the right-handed system. The skymap display is
defined to display every frame with the Z axis up, X axis into the
page and Y axis out to the left. So in the skymap, using this frame,
Z or up is the spin axis of Saturn, into the page is the boresight.
The Saturn frame, XINCA_SATURN_CENTERED, a frame dynamically defined as
follows. The primary axis is the CASSINI spacecraft-to-Saturn vector
and is labeled X. The secondary (Z) axis is the Z axis of the
IAU_SATURN frame (the Saturn spin axis). The Y-axis completes the
right-handed system.
The Titan frame, XINCA_TITAN_CENTERED, a frame dynamically defined as
follows. The primary axis is the CASSINI spacecraft-to-Titan vector and
is labeled X. The secondary (Z) axis is the Z axis of the IAU_TITAN
frame (the Titan spin axis). The Y-axis completes the right-handed
system.
The INCA Azimuth and elevation frame, CASSINI_MIMI_INCA_LL, is the
primary axis X is the INCA boresight axis which goes into the page.
The secondary Z axis is the Z axis of Cassini. The Y-axis completes
the left-handed system.
The definition of the Saturn equatorial system,
SATURN_EQUITORIAL_SYSTEM, frame has the primary axis, labeled Z,
parallel to the Saturn spin axis. The Y-axis is then defined as the
cross product of this vector with the Saturn-Sun vector. The X-axis
completes the right-handed system and is directed roughly sunward,
lying in the plane containing both Z and the Saturn-sun vector.
The MIMI INCA display software also displays the axis of Saturn using
the Saturn Kilometric Radiation frame (SKR). Due to the work of the
RPWS team we now have several Saturn Kilometric Radiation frames
available for use.[1] The Z-axis is coincident with the instantaneous
body rotation vector (spin axis) of Saturn. [1] A SLS4 Longitude system
based on a tracking filter analysis of the rotation modulation of
Saturn kilometric radiation. D.A. Gurnett, et. al.
Software
========
There is IDL software provided on the MIMI web site, which will
calibrate the INCA images conversion of count rates into flux. In
addition, web applications are provided on the MIMI web site to
display the INCA images in the skymap and thumbnail displays both
singly and in multiple formats.
Media/Format
============
These data are supplied to the Planetary Data System via electronic
means and are then broken into segments based upon the media currently
prescribed by PDS."
CONFIDENCE_LEVEL_NOTE = "
Confidence Level Overview
=========================
This data set contains all calibrated data for the INCA Detector as
part of the Cassini MIMI instrument for the interval described above.
Every effort has been made to ensure that all data returned to APL
from the spacecraft is included and that the calibrated browse data
products are accurate.
As of this writing there are no known issues associated with the INCA
detector that would limit the usability or reliability of the data.
Review
======
The MIMI INCA data will be reviewed internally by the Cassini MIMI
team prior to release to the PDS. The data set will also be peer
reviewed by the PDS.
Data Coverage and Quality
=========================
All data in the stated interval are included, to the best of our
knowledge and attempts to determine completeness.
Large Data Gaps:
1. Post SOI 2004-187 - 2004-193 - Spacecraft Safing
shut off
2. Tour 2005-006 - 2005-015 -
3. Tour 2007-254 - 2007-258 - Spacecraft Safing
shut off
3. Tour 2007-279 - 2007-291 - Spacecraft Flight
S/W testing shut off
3. Extended Mission 2009-071 - 2009-076 - Spacecraft Thruster
branch swap,deactivated
S48 background sequence.
3. Extended-Extended Mission 2010-306 - 2010-319 - Spacecraft Safing
shut off
3. Extended-Extended Mission 2012-293 - 2012-303 - Spacecraft Propellant
Gauging Test shut off.
On those days for which the instrument did not collect data either due
to the instrument being off or due to communication issues, the data
set will not contain any files.
Limitations
===========
As noted above there are no know issues associated with the data from
the INCA detector as of the writing of this catalog."
END_OBJECT = DATA_SET_INFORMATION
OBJECT = DATA_SET_MISSION
MISSION_NAME = "CASSINI-HUYGENS"
END_OBJECT = DATA_SET_MISSION
OBJECT = DATA_SET_TARGET
TARGET_NAME = "SATURN"
END_OBJECT = DATA_SET_TARGET
OBJECT = DATA_SET_HOST
INSTRUMENT_HOST_ID = CO
INSTRUMENT_ID = MIMI
END_OBJECT = DATA_SET_HOST
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "VANDEGRIFFETAL2012"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "KRIMIGISETAL2004"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "MANWEILERETAL2005"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
OBJECT = DATA_SET_REFERENCE_INFORMATION
REFERENCE_KEY_ID = "KUSTERER&BURKE2003"
END_OBJECT = DATA_SET_REFERENCE_INFORMATION
END_OBJECT = DATA_SET
END
|