INVAR/NEWMAG 1967


Authors: C. E. McIlwain, A. Hassitt
University of California, San Diego
CASS C-011
La Jolla, California 92093
NSI-DECnet: CASS::CARL
Parameter: Computation of magnetic field parameters and L-value from spherical harmonics coefficients

Brief Description:
This package includes the subroutine INVAR to calculate L-values at any specified point in space (geocentric coordinates) and NEWMAG to calculate the vector components of the Earth's main (core) magnetic field as given by the GSFC (9/65) model. Subroutine INTEG determines the value of the integral invariant I by numerically integrating along the field line from the specified point of interest to its conjugate point. An input accuracy parameter controls the number of points (maximum: 200) used in the integration. CARMEL computes the shell parameter L from I and B by using McIlwain's (1961) formulas. These programs should be used only for the time range 1960-1965 for which the GSFC (9/65) is considered valid. The package was designed for card deck operation on an IBM 7094 and 360 mainframe. Hilberg (1971) compared L-values calculated with INVAR, SHELLG, and INTELG.

References:
C. E. McIlwain, Coordinates for Mapping the Distribution of Magnetically Trapped Particles, J. Geophys. Res. 66, 3681, 1961.

A. Hassitt and C. E. McIlwain, Computer Programs for the Computation of B and L, NSSDC 67-27, Greenbelt, Maryland, 1967. (B17336)


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