摘要
基于相位差方法的天文目标高分辨率成像,是利用在焦面和离焦位置上同时采集的一对或者多对短曝光图像,对目标和大气湍流引入的波前相位分布进行估计．在计算机模拟望远镜成像系统和相位差方法图像采集过程的基础上,利用信号估计和最优化理论,确定了高斯噪声模型下的目标函数,采用适合于大规模无约束优化的有限内存拟牛顿法对图像恢复问题进行了数值求解．恢复结果表明,基于相位差方法的高分辨成像技术,可以有效地克服大气湍流的影响,解决天文扩展目标的图像恢复问题．
The high resolution imaging of astronomical object based on phase-diversity method is a technique for obtaining estimates of both the object and the distribution of wavefront induced by atmospheric turbulence, by exploiting the simultaneous collection of one or more pairs of short-exposure images. One of the pair images is the conventional focal-plane image and another is formed by further blurring the focal-image by defocus. The telescopic optical system and image collection system of phase-diversity method are simulated by using computer in this paper. Based on signal estimation theory and optimization theory, the objective function is derived under additive Gaussian noise model. The resulting large scale unconstrained optimization problem is solved numerically using a limited memory BFGS method. The restoring results demonstrate that the phase-diversity method is remarkably efficient for removing the effect of atmospheric turbulence and solving the image restoration problem of astronomical extended object.
出处
《天文学报》
CSCD
北大核心
2007年第1期113-120,共8页
Acta Astronomica Sinica
基金
国家863计划(863-2-7-7-4)资助
关键词
望远镜
仪器
高角分辨率
技术
方法
数值
telescope, instrumentation： high angular resolution, techniques： high angular resolution, methods： numerical
