European Space Agency

Royal Belgian Institute for Aeronomy

um523 - GEO to GSM transformation

subroutine  um523(kunit)

Parameters:

kunit [integer4,in] :: file unit for the summary table (see note of ut990()).

Description

The subroutine um523() computes the transformation array from GEO coordinate to GSM coordinate as well as the geomagnetic dipole tilt angle. The results are stored in the arguments mext.trans and mext.tilt of the common block uc140. As input, the subroutine uses the position of the Sun and the orientation of the magnetic dipole axis stored in the arguments msun and mint of the common block uc140, respectively. Note that the Sun position can be easily modified by the use of subroutine um522().

When kunit is greater than zero, a summary table is written by the subroutine.

Diagnostics

• the program is aborted when an error to the output device occurs.

Common Blocks

• uc140 - magnetic field

• uc160 - general constants

Dependencies

Called by

• um520 - select an external magnetic field model

• um539 - evaluate the magnetic field

Calls

None

See also

• um524 - GEO to SM transformation

Reported Bugs

None

Examples

None

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UNILIB/tags/v3.02