Non-stationary Gaussian random fields on hypersurfaces: Sampling and strong error analysis

A flexible model for non-stationary Gaussian random fields on hypersurfaces is introduced. The class of random fields on curves and surfaces is characterized by a power spectral density of a second order elliptic differential operator. Sampling is done by a Galerkin--Chebyshev approximation based on the surface finite element method and Chebyshev polynomials. Strong error bounds are shown with convergence rates depending on the smoothness of the approximated random field.