A geomagnetic reference field for Canada 1985

Abstract

The recently developed technique of spherical cap harmonic analysis (SCHA) is ideally suited for the analysis of potential fields over a portion of a sphere. SCHA is a regional analog of ordinary spherical harmonics involving associated Legéndre functions of integral order but non-integral degree, and ensures that the curl and divergence of the magnetic field vector are zero (Haines 1985a). The method has been used to produce a Canadian Geomagnetic Reference Field for 1985 (CGRF 1985) and the associated series of magnetic charts.