Near Field Phase Recovery Exploiting Only One Measurement Surface And A Smart Warping Sampling Strategy

A recently introduced and successful strategy for addressing the phase retrieval problem from far-field measurements is now applied to the near-field case. This extension maintains its core methodology of treating 2-D phase retrieval as a series of 1-D recovery problems. These latter are effectively solved by integrating the Spectral Factorization method with a selection process reminiscent of solving a crossword puzzle. The expansion into the near-field domain involves leveraging key findings related to efficient planar near-field measurements through warping strategies. This approach restores the bandlimited nature of scattered fields, allowing the method to retain its advantages over state-of-the-art techniques. These advantages include the requirement for only a single measurement surface and the ability to achieve the optimal solution without resorting to computationally expensive global optimization algorithms.