Phase retrieval in sparse aperture systems with phase diversity: a trade space study

Abstract

Sparse-aperture (SA) telescopes are a technology of interest in the field of remote sensing. Significant optical resolution can be achieved by an array of sub-apertures, mitigating size and weight limitations of full aperture space-deployed sensors. Much of the analysis to date has been done with the assumption that an extended scene is spectrally flat and each pixel has the same spectrum (gray-world assumption). Previous work has found the gray-world assumption is not valid when imaging a spectrally diverse scene and/or when the optical configuration is heavily aberrated. Broadband phase diversity (BPD) is an image-based method to detect the aberrations of a system. It also assumes a gray-world. Digital simulations that quantify the limitations of BPD with respect to spectral diversity of the extended scene, the RMS of the optical path difference (OPD), noise of the system, and band width of the sensor are presented.