Application of spherical Slepian functions to aeromagnetic data and in crustal field modelling

Models of the crustal magnetic field are typically represented using spherical harmonic coefficients. Rather than spherical harmonics, spherical Slepian functions (hereafter just Slepian functions) can be employed to produce a locally and also globally orthogonal basis in which to optimally represent the data in a region up to a given degree. The region can have any arbitrary shape and size. In this poster we show some of the possible applications of Slepian functions to aeromagnetic data studies: optimally separate a crustal field model into its oceanic and continental regions in order to investigate the spectral content; compactly describe regional spherical harmonics in a sparse manner; reconstruct a smooth function from a series of input data points