Timing residuals under the assumption of the Cs noise model. Top: ToA residuals as a function of MJD, showing flat, Gaussian residuals. Middle: ToA residuals as a function of the orbital phase (orbital position from the ascending node, true anomaly + periastron) excluding the h₃ and ς parameters from the timing model, showing the full amplitude of the Shapiro delay signal. The continuous blue line depicts the predicted Shapiro delay described by h₃ = 3.45 μs and ς = 0.858. Bottom: same as the middle plot, but the orthometric Shapiro delay parameters are now included in the model, resulting in flat, Gaussian residuals.