Examination of Gaussian prior for even and odd spectra modelled by Brownian bridge process. The spectral discretisation = 5.68 GHz is used, and the lower and upper spectral limits are set to = 0 GHz and = 3747.4 GHz (Nyquist assumptions), respectively. The scalings of the processes are chosen by V2. (a) Prior samples and for even and odd spectra. The spectra vanish towards the spectral limits. (b) Prior samples mapped to data domain to give even (odd) data-like quantity for optical path difference obtained for mm and = 0. With increasing distance to the origin, the amplitude drops which is well bounded by the signal envelopes for the chosen bandwidth . Fourier coefficients up to order = 64 and 330 settle in the double-sided domain and single-sided domain , respectively.