‘Proof of concept’ with an isolated signal in the xy plane, with wavenumber k_x = 0.58 Mm⁻¹, and no frequency. The first panel shows a 1D slice in the y axis, taken at an arbitrary time. The middle panel shows the amplitude spectrum from the DFT, averaged across the y and time axes, where there is a sharp peak at the 0.58 Mm⁻¹, whilst the third panel shows the most significant signal per pixel in the domain. In grey, the MSF, ω, is shown, and is zero as expected.