Improving the precision and efficiency of an optical telescope array by the piecemeal method

Angular localization of remote optical objects is a fundamental challenge in fields such as remote sensing and astrometry. We propose the piecemeal method for telescope array, with explicit formulas showing strictly its key advantages: higher precision, efficiency and robustness, which are further confirmed by numerical simulations. Specifically, our method achieves a 10⁴ precision improvement with 10⁵ photon number reduction compared to existing telescope arrays, and achieves precision improvements of 10³ and 10² over the Gaia telescope and the ultimate quantum limit for incoherent imaging, respectively, under comparable photon numbers. We have also presented a reference-object-based implementation framework for our method that seamlessly integrates with existing optical interferometric systems.