a) A single two-dimensional Gaussian function, Eq. (B.8), with σ_x = σ_y = 1.9 and μ_x = μ_y = 0 representing a Gaussian beam of a telescope. b) Cut through the Gaussian function described in a) at half height. c) A single two-dimensional Gaussian function, with σ_x = σ_y = 1.1 and μ_x = 0.5 and μ_y = 0.9 representing a Gaussian beam of a point source. d) Cut through the Gaussian function described in c) at half height. e) Convolved Gaussian of telescope and point source as given by Eq. (B.10). f) Cut through the convolved Gaussian function described in e) at half height.