Evaluation of magnetospheric internal magnetic field models and existing software
Abstract
In preparation for analysis of the CRRES databases (to be taken from 1990 to 1995) and, in particular, for an updated static radiation belt model, a comparison has been made of four magnetospheric internal magnetic field models. Since there is interest in radiation belt models out to geosynchronous altitudes, it will be necessary to consider the external magnetic field models as well, but for now just the internal models will be discussed. The four models reviewed here are Barraclough, MAGSAT, IGRF 1985, and Cain. Each of these has an optimal time period associated with it: Barraclough 1975, MAGSAT 1980, IGRF 1985, and Cain 1990. In the subsequent sections of this report, the derviations of these models will be summarized. They are all based on these spherical harmonic expansion of the magnetic field's scalar potential. The data used to determine each set of coefficients will be briefly discussed. Then the models will be evaluated by comparing the magnetic field and Lshell values obtained from each of the models. Finally, various computer codes which use these models to evaluate the field and Lshell, will be compared and evaluated in terms of their performance (i.e., accuracy and speed). A primary concern for radiation belt models is reduction of the number of binning parameters by using BL coordinates.
 Publication:

Scientific Report No. 3
 Pub Date:
 January 1990
 Bibcode:
 1990rade.rept.....J
 Keywords:

 Computer Programs;
 Computerized Simulation;
 Data Bases;
 Earth Magnetosphere;
 Magnetic Fields;
 Static Models;
 Moments;
 Optimization;
 Outer Radiation Belt;
 Scalars;
 Synchronism;
 Geophysics