I can't find any useful page which explains in detail how to calculate the equivalent resolution of an optical interferometric telescope. I found out, after LONG search, the formula to calculate standard-telescope resolution: Resolution (Km) = 5,5680 * 10^-4 * Distance (Km) / diameter (mm) Does it exist such a formula for interferometric telescopes? I don't think I can just use two 110mm telescope 1 Km far away to obtain a 1.000.000 m equivalent telescope! Some physic constraint must exist! Which ones? How distance and diameters of single telescopes relates to equivalent-telescope angular resolution?