Brief Description:
This package includes the programs ALLMAG for calculating geomagnetic vector
components, INVARA for calculating L-values, and LINTRA for field-line tracing,
all designed and tested by Stassinopoulos and Mead (1972). These subroutines
operate with the usual spherical harmonics representation of the Earth's main
(core) magnetic field. Seven sets of coefficients are included in the code:
GSFC (9/65),
GSFC (12/66),
POGO (10/68),
POGO (8/69),
IGRF 1965, Leaton et al. (1965),
and Hurwitz (1970). ALLMAG is equivalent to Cain's FIELDG program, with the
added flexibility of the choice of seven models. INVARA is a version of
McIlwain's INVAR subroutine adopted for use with the ALLMAG field calculation
subroutine. LINTRA traces field lines from any point in space to a specified
altitude in the same or opposite hemisphere, using any of the models contained
in ALLMAG.
The modified ALLMAG versions ONEMAG (#PG-12C, D) and DEKMAG (#PG-12E) are also available from NSSDC. ONEMAG contains built-in coefficients for only one field model, namely IGRF 1965 (#PG-12D) or IGRF 1980 (#PG-12C). DEKMAG reads in coefficients, rather than having built-in coefficients (as DATA statement). All programs were designed for card deck operation on an IBM 360/91 mainframe.
Availability: On one tape (NSSDC ID #PG-12A)
References:
B. R. Leaton, S. R. C. Malin, and M. J. Evans, An Analytical Representation of
the Estimated Geomagnetic Field and Its Secular Change for the Epoch 1965.0,
J. Geomag. Geoelectr. 17, 187, 1965.
E. G. Stassinopoulos, Computer Codes for Geomagnetic Field-Line Tracing and Conjugate Intersect Calculations, GSFC, Report X-642-68-429, 1968. (B09143)
L. Hurwitz, Mathematical Model of the 1970 Geomagnetic Field, ESSA Coast and Geodetic Survey, May 4, 1970.
E. G. Stassinopoulos, and G. D. Mead, ALLMAG, GDALMG, LINTRA: Computer Programs for Geomagnetic Field and Field-Line Calculations, National Space Science Data Center, Report 72- 12, Greenbelt, Maryland 1972. (B11996)
Go to the Geomagnetic Field Models index Go to the Space Physics Models page
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| If you have questions/comments about the various models available from NSSDC, contact:Dr. Dieter K. Bilitza. If you have any questions/comments about geomagnetic field models and Web access to run models, contact: Dr. Natalia Papitashvili, National Space Science Data Center, Mail Code 630, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 |
NASA Official: Dr. Robert McGuire, Head of the Space Physics Data Facility
Last Updated: 07 November 2003, NEP