傅里叶望远镜外场实验性能改进和结果分析

为了实现对傅里叶望远镜成像系统更接近实际的仿真,改进了外场实验系统结构。采用反射式目标,利用准直扩束镜替代空间滤波器和准直透镜,使用大靶面电荷耦合器件作为监视器。在无大气和包含200m水平大气两种情况下,分别对2.5mm的4种不同空间频谱分布目标进行实验。实验选用9×9,17×17,33×33和65×65傅里叶分量分别进行重构。最高成像角分辨率为3.5″。结果表明含大气与无大气重构结果的Strehl比值相近,从而证明傅里叶望远镜成像系统能够克服下行链路低阶大气扰动的影响。

Improvement of Performance and Analysis of Results of Field Experiments of Fourier Telescope

In order to make the simulation of the Fourier telescope imaging system close to reality, the structure of field experimental system is improved. Reflected objects are used, space filters and collimation lenses are replaced by collimation beam-expanders, and large sensitive area charge coupled device is used to monitor imaging. For different cases without atmosphere and with 200 m level atmosphere, 4 objects with different spatial spectra are researched. 9×9, 17×17, 33×33 and 65×65 Fourier components are used for reconstruction. The best angular resolution of imaging is 3.5″. The results indicate that the Strehl ratios of reconstructed images with 200 m level atmosphere are close to those without atmosphere, and then prove that the Fourier telescope imaging system is immune to effects of low-order atmospheric turbulence.