Time-delay deviation, τ_i, from Eq. (8) as a function of the time delay, where we have binned up the samples from the corresponding test set with similar time delays (bin size: two days) for the LSN Ia from Fig. 4. The vertical gray line marks the true absolute time delay from the mock LSN Ia system. The corresponding test set has LSN Ia systems that span a range of input time-delay values, which include the vertical gray line. Results from the FCNN network are shown in the left panel, and the RF is presented in the right panel.