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Trapped Radiation ENvironment model Development


[ Name | Synopsis | Arguments | Description | Diagnostics | Common Blocks | Dependencies | See Also | Reported Bugs | Examples ]


    Subroutine UM530 - evaluate the magnetic field vector


      RECORD /zgeo/ mpos
      RECORD /zvec/ mb
      INTEGER*4     ifail
      CALL UM530 (mpos, mb, ifail) 


    Geographic position in geocentric coordinates (GEO) [in]
    Magnetic field vector [out]
    Error flag (see diagnostics) [out]


    The subroutine UM530 evaluates the magnetic field vector at a geographic location. Before the first call to subroutine UM530, the magnetic field parameters have to be initialized. These parameters are stored in the common block UC140 but they can be modified with the help of the subroutines UM510 and UM520. The subroutines UM510 and UM520 allow to select an internal geomagnetic field model (e.g. IGRF) and an external magnetic field (e.g. Tsyganenko), respectively.

    The geographic location mpos has to be provided in geocentric spherical coordinates. The subroutine UM530 returns the spherical component and the intensity of the magnetic field vector. Note that the magnetic field vector is evaluated by the subroutine even when the error flag ifail is returned with the negative values -53002, -53003 and -53004. The diagnostics provided by the subroutine UM530 are controlled by the parameters xrmin, xbmin, xtmin and xbmax stored in the common block UC192.


    -53001, position too deep inside the Earth
    -53002, too small value of the magnetic field intensity
    -53003, too large value of the geomagnetic latitude
    -53004, too large value of the magnetic field intensity
    -53005, incorrect value of the co-latitude

Common Blocks

    UC140, magnetic field description
    UC160, general constants
    UC192, control parameters, set 2


Called by

    UL220, get information on a magnetic field line segment
    UD328, evaluate the second derivative of B
    UD329, interpolate between two or three points
    UD332, evaluate the magnetic flux through a spherical pie
    UF411, search a local magnetic equator
    UF421, initialize and close a field line segment
    UF423, Runge Kutta step
    UF425, evaluate the curvature of the field lines
    UM539, evaluate the magnetic field
    UT998, evaluate the magnetic field vector and the normal to the field line


    UM531, geomagnetic field
    UM532, external magnetic field
    UM533, distance to the magnetopause
    UM535, geocentric to geodetic transformation
    UM537, Kluge evaluation of the geomagnetic field

See also

    UM510, select a geomagnetic field model
    UM520, select an external magnetic field model
    FAQ G.05 Which are the coordinates and units used ?

Reported Bugs



    #1, evaluation of the magnetic field vector