Peak-height ratios as a function of the spot latitude (left) and visibility time (right) for the inclination angles i = 30°, 50°, and 70° and for different spot areas (top panel), different spot-to-photosphere intensity ratios (second row), various differential rotation parameters (third row), and different limb-darkening laws (bottom panel). For these simulations, the default values of the spot radius and intensity contrast are R_S ~ 5.7° and C_S = 0.67. We use the solar rotation (Ω_{eq, ⊙}, α_⊙, and β_⊙) as the default rotation profile. Finally, the default limb-darkening law is the quadratic one with parameters a = 0.5287 and b = 0.2175. [R_S ~ 11.5° ⇔ A_S = 20 000 μHem, R_S ~ 5.7° ⇔ A_S = 5000 μHem, R_S ~ 2.6° ⇔ A_S = 1000 μHem, R_S ~ 1.8° ⇔ A_S = 500 μHem, R_S ~ 1.3° ⇔ A_S = 250 μHem]