POLAR TIMAS
*****PA******
SUMMARY PLOTS
These plots provide an overview of high temporal (2 spin or 12 seconds) resolution ion pitch angle distributions
for perigee passes from launch until December 8, 1998.
See also the EJD and AN plot types.
First (top) color panel
- Pitch angle distribution of H+ obtained by integrating over the energy range 4.5 < E/Q < 33 keV
- Number flux in units of (cm^2-s-sr-keV/e)^-1 is encoded using the color bar on the right
- All perigee data are from the southern hemisphere, so a pitch angle of 0 degrees corresponds to to ions flowing
up the field line from the ionosphere
below.
- Weak or missing fluxes near 0 degrees pitch angle indicate the existance of an "ion loss cone" type
distribution.
Second color panel
- Pitch angle distribution of H+ integrated over the energy range 0.6 < E/Q < 4.5 keV
- Same format as first color panel
Third color panel
- Pitch angle distribution of H+ integrated over the energy range 16 < E/Q < 600 eV
- Same format as first color panel
Solid lines between third and fourth color panels
- Color of upper line indicates source of H+ data
- Color of lower line indicates source of O+ data
- Green indicates data are from PAD data products and therefore have the highest angular resolution (~11 degrees)
available from the TIMAS instrument.
- PAD's (Pitch Angle Data product) are intended to provide the maximum angular resolution attainable from the
TIMAS where it is reasonable to assume the distributions are
gyrotropic in the measurement frame. PADs are again specified independently by detector half and M/Q; however,
they are further specified by the
number of pitch angle elements required and whether or not the data are summed over adjacent energy steps. The
Data Processor uses the MAGAZ and
MAGEL signals provided by the spacecraft to select the 9 detector sector elements that best characterize the
pitch angle distribution for each
detector half in either the first or both spin sectors that intercept the magnetic field vector within the
TIMAS field of view. Each PAD consists
of 63, 126, or 252 energy, pitch-angle elements. See This Page for more
information about on board acquisition and
processing of data.
- Orange indicates the data are from MRDF data products with medium angular resolution (~22 degrees).
- As with the LRDF described below, the MRDF are defined independently by detector half and M/Q; however,
MRDF are always for a single spin period.
MRDF are generated from the spin buffer by summing over two adjacent detector sectors and summing over two
adjacent spin sectors for the elements
nearest the spin axis, thus producing an array of 104 solid angle elements per detector half. The MRDF may
be specified to be further summed over
adjacent energy steps (i.e. adjacent odd or adjacent even depending on spin). Thus each (of eight possible)
MRDF is a 3-D distribution with
either 728 or 1456 velocity space elements. See This Page for more information
about on board acquisition and
processing of data.
- RED indicates the data are from LRDF data products with low angular resolution (~45 degrees).
- Data from each detector half and each M/Q are treated separately and can be integrated over 2^N spin
periods (0 <= N <= 5), thus 8 separate
LRDF are possible. LRDF are generated from the spin buffer data by summing over adjacent even and/or odd
energy steps, summing over two adjacent
spin sectors, and summing over four adjacent detector sectors except for those nearest to the spin axis which
are summed over 2 sectors. Thus
each LRDF represents a 3-D distribution with 224 velocity space elements (7 energy x 8 spin angles x 4 polar
angles). This resolution is
sufficient to characterize most magnetospheric ion distributions. See This
Page for more information about on board acquisition and
processing of data.
Fourth color panel
- Pitch angle distribution of O+ integrated over the energy range 4.5 < E/Q < 33 keV
- Same format as first color panel
Fifth color panel
- Pitch angle distribution of O+ integrated over the energy range 0.6 < E/Q < 4.5 keV
- Same format as first color panel
Sixth color panel
- Pitch angle distribution of O+ integrated over the energy range 16 < E/Q < 600 eV
- Same format as first color panel
The line and number panel labeled BCR ICP and E Range on the left
- The solid line gives the Background Counting Rate (BCR) in a log scale. No scale is indicated.
Values near the top of the panel indicate regions where the signal (and therefore the
information in the color panels above) is degraded because of high background counting rates.
- The color of the BCR rate line indicates instrumental status. Green indicates OK. Orange
indicates that caution should be used in applying the data. Red indicates that the data are
not valid.
- The TIMAS mode in use at the time is indicated by its ICP Table #. For a description of
TIMAS modes by ICP table # see the TIMAS Mode description page
- The color of the solid line above the UT information encodes the energy range sampled by
the TIMAS instrument. Green indicates full ( 15 eV < E/q < 33 keV). Orange indicates the
reduced energy range ( 15 eV < E/q < 25 keV ). Red indicates the low energy range ( 15 eV <
E/q < 2 keV ).
Information about the orbit in tabular format
- UT: Universal time in hours:minutes
- R(Re): Geocentric distance of Polar in units of Earth radii
- L(Re): McIlwain L parameter at the location of Polar
- MLT(Hr): Magnetic Local Time at the location of Polar in decimal hour format
- MagLAT: Geomagnetic Latitude at the location of Polar in degrees.
- InvLat: Invariant Latitude at the location of Polar in degrees.
Prepared by WK (Bill) Peterson, May 2008.