STK SEET Geomagnetic Field Graphics
The STK SEET Geomagnetic Field component evaluates the magnetic field and performs field-line tracing using multiple models. Beyond several Earth radii, the Earth's magnetic field is increasingly distorted by the solar wind interacting with the Earth's magnetosphere; the total magnetic field is therefore modeled as a mostly dipolar main-field model, plus an external (magnetospheric) field model.
There are three right-handed frames to which geomagnetic fields are referenced. The Geomagnetic (MAG) frame has its Z axis aligned with the magnetic north pole, with its minus-X axis constrained toward the Earth-fixed pole. The Geocentric Solar Magnetospheric (GSM) frame has its X axis aligned with apparent Sun vector from Earth, with its Z axis is constrained toward magnetic north pole. The Solar Magnetic (SM) frame has its Z axis aligned with magnetic north pole, with its X axis constrained towards apparent Sun vector from Earth.
For additional background information, consult: SEET: Space Environment and Effects Tool for STK (PDF).
Option | Description |
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Show Magnetic Field | Show magnetic-field lines in the 3D graphics window, if checked. |
Main Field |
Options are:
|
External Field |
Options are:
|
IGRF Update Rate | The period of the frequency at which IGRF model coefficients will be re-evaluated from the conventional ICRF coefficients spaced approximately every five years. |
Option | Description |
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Min North Lat | Specify the starting geomagnetic latitude (must be less than or equal to Max North Lat). |
Max North Lat | Specify the ending geomagnetic latitude (must be greater than or equal to Min North Lat). |
Number Lat Lines |
Number of latitude lines between Min North Lat and Max North Lat. |
Number Lon Lines |
Total number of longitudinal half-plane cross-sections, equally spaced and starting from the Starting Longitude. |
Starting Longitude |
The magnetic longitude from which the set of longitudinal cross-sections start, measured as increasingly positive toward the east, in the Solar Magnetic (SM) frame. |
Field Line Refresh Rate |
The time period of the frequency at which the magnetic field lines will be recalculated for animation purposes. |
Option | Description |
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Color Mode |
Options are:
|
Ramp Start | Color corresponding to the lowest mapped value. |
Ramp Stop |
Color corresponding to the highest mapped value. |
Max Translucency |
The level of field-line translucency of corresponding to the minimum mapped field strength (available when the Color Mode is Latitude Line). |
Scale |
Options are:
|
Style | Sets the style of the field contour line. |
Width | Sets the width of the field contour line. |
Olson, W. P. and K. A. Pfitzer (1977), Magnetospheric magnetic field modeling, Annual Scientific Report, AFOSR Contract No. F44620-75-C-0033.