Improved field performance of Fourier telescopy in real atmosphere turbulence using new phase closure iteration for object spatial spectrum reconstruction

Abstract

Fourier telescopy is a remote imaging method that generates several interfering fringes from a coherent laser transmitter array. In this technique, the spatial spectrum of an object is acquired by sweeping fringes of different spatial frequencies and directions on the object. Most traditional triplet phase closure iterations are accomplished by three beams and are used to alleviate the phase aberration induced by atmospheric effects. For reducing the effect of scintillation, which is an atmospheric turbulence effect, we propose a phase closure method wherein the complex amplitude of four beams are combined in iteration. We evaluated the performance of the proposed method both theoretically and experimentally. We conducted the field experiments at 200 m and 1.2 km. The results demonstrated that the proposed phase closure method performs well in enhancing the image quality in a multibeam array when there is scintillation in the atmosphere.

Keywords

• Fourier telescopy
• Remote sensing
• Phase closure