Example of light curve construction in the LSST g-band. The selected source features M_BHB ≃ 4.91 × 10⁷ M_⊙, z_BHB ≃ 1.95, P_obs ≃ 2.45 yr, e_BHB = 0.6, and q_BHB ≃ 0.7. First panel: Random DRW realisation associated with the MBHB. Second panel: Realisation of a single m_g(t) light curve. The dots represent the tailored 𝒯₃ data points. The solid line implements the DRW shift from the first panel, plus the manipulations presented in Sections 4.1–4.4. Third panel: Periodogram analysis of m_g(t). The vertical green dashed lines represent the Keplerian frequency and the second and third harmonics, while the corresponding shaded regions represent the frequency bin width. Finally, the vertical thick shaded grey lines mark the periodogram f_min and f_max values.