面向弱引力透镜巡天的图像处理技术研究

弱引力透镜剪切场的精确测量是当前及将来大天区弱引力透镜巡天研究的瓶颈问题。其中点扩散函数（PSF）的精确测量和多次曝光图像的无偏叠加则是其中的两个主要难点之一。本项目将主要聚焦在这两个问题上，着力解决以下三个技术难题：1）利用正交基函数和星的图像，构建光滑、紧致的点扩散函数主成分；2）利用多次曝光的星系的图像精确重建PSF场；3）建立一套去PSF效应的图像叠加技术。每一项内容都引入了新的技术，都将显著改善弱引力透镜剪切场测量的系统误差。

The precise measurement of the weak-lensing shear field is the key and bottleneck problem for large-scale weak lensing surveys in the future. The precise reconstruction of point spread function(PSF) and non-bias combination of multi-exposured images is the two key difficulties among those issues. This proposal will focus on this two difficulties and try to resolve three technical problems:1)constructing of smooth and compact principle components of PSF using theoretical basis functions and images of stars. 2) constrain PSF filed using multi-exposured images of galaxies.3)establish a pipe line for image combination with de-convolution of PSF. New technics will be introduced to each topics and each of them will be very helpful for the correction of systematics in the measurement of the weak-lensing shear field.