论文标题
避免剪切测量中的几何边界效应
Avoiding the Geometric Boundary Effect in Shear Measurement
论文作者
论文摘要
在图像处理中，源检测不可避免地会受到图像中几何边界的存在，包括CCD的物理边界以及由于柱缺陷，明亮的衍射峰值等引起的掩盖区域的边界。它可能导致边界附近的加性剪切偏置。我们建立了一个现象学模型来理解偏见，并提出了一种简单的方法，可以有效消除几何边界对剪切测量的影响。我们使用模拟和DECAM传统调查的第三个数据发布中的Z波段成像数据证明了该方法的准确性和效率。
In image processing, source detections are inevitably affected by the presence of the geometric boundaries in the images, including the physical boundaries of the CCD, and the boundaries of masked regions due to column defects, bright diffraction spikes, etc.. These boundary conditions make the source detection process not statistically isotropic. It can lead to additive shear bias near the boundaries. We build a phenomenological model to understand the bias, and propose a simple method to effectively eliminate the influence of geometric boundaries on shear measurement. We demonstrate the accuracy and efficiency of this method using both simulations and the z-band imaging data from the third data release of the DECam Legacy Survey.
