Magnetic mapping

The magnetic mapping is fulfilled by the magnetic field line tracing from the satellite position up to the Ionosphere (stop trace at the altitude 110 km).
Several version of the external magnetic field model can be used during magnetic mapping (see the reference). The real values of the Kp parameter can be taken into account.
As a rule the Tsyganenko [1987] external magnetic field model and IOPT = 3 (Kp = 2) are used. This value of the IOPT parameter corresponds to the middle geophysical conditions.
The output file includes the following information:

The footprints' geographical and geomagnetic co-ordinates in the Northern and in the Southern Hemispheres.
The corrected geomagnetic co-ordinates
McIlvain L value and Invariant latitude (for R <6 RE). >
The identification (MOD IOPT) of the used magnetic field model's version.

For more details see the output file parameters description.

The name of the output file contains the information as follows:

Name of stage (1 letter: m or a).
Name of satellite (1 letter: t or a).
YYMM - year and month
'di' - decade number (i = 1, 2, or 3).

The names of stage:

'm' corresponds to the calculations during flight for scientific planning.
The output files corresponding to this stage shows the parameters as a function of the Moscow time (MT=UT+3h) with 1 h step.
'a' corresponds to the aposteriory (more precisely) satellite motion calculation.
The output files corresponding to this stage shows the parameters as a function of the UT with 10 min step.

The decades include the part of month as follows:

the decade d1 includes the days 1 - 10,
the decade d2 - the days 11 - 20,
the decade d3 includes the rest days of month from 21.

Each decade includes couple of day's extension.

For example the file with name aa9610d1.geo contains the information corresponding to the aposteriory magnetic mapping for INTERBALL Auroral Probe for the first decade of October 1996.

Reference

Tsyganenko, N. A., Global quantitative models of the geomagnetic field in the cislunar magnetosphere for different disturbance levels, Planet. Space Sci., 1987, 35, 1347-1358

Tsyganenko, N. A., A magnetospheric magnetic field model with a warped tail current sheet, Planet Space Sci., 1989, 37, 5-20.

Tsyganenko, N. A., Quantitative models of the magnetospheric magnetic field: Methods and results. Planet Space Sci. 1990, 54. 75.

McIlwain, C. E., Co-ordinates for mapping the distribution of magnetically trapped particles, J. Geophys. Res., 1961, 66. 3681-3691.

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Dr. Victoria Prokhorenko
Dated 17 January 1999