Fine Phasing of Multi-aperture Imagers by the Simulated Annealing Algorithm: Numerical Simulations and Laboratory Experiments for High-resolution Optical Remote Sensing

Abstract

Satellite-borne multi-aperture imagers are a promising optical system for high-resolution Earth observation. A significant challenge to realize such an imager is to develop an in-orbit fine phasing method to complete precise piston-tip-tilt alignment between sub-apertures to achieve diffraction-limited imaging performance. This study demonstrated the use of the simulated annealing algorithm for iterative scene-based fine phasing. One advantage of this approach is the correction capability of the piston-tip-tilt misalignment with a minimal hardware configuration. Numerical simulation revealed the relationship between fine phasing performance and the temperature parameters in the algorithm. Besides, algorithmic comparison with the stochastic parallel gradient descent algorithm, another approach capable of scene-based fine phasing, is also presented. Furthermore, we developed a miniaturized multi-aperture imaging system with 37 hexagonal mirror segments for our laboratory-scale optical experiments. The demonstration experiment showed the high-accuracy fine phasing results for typical extended scenes obtained by optical remote sensing.