论文标题
偏见的时刻不足的采样来源
Biased Moments of Undersampled Sources
论文作者
论文摘要
在图像上计算的空间强度矩可以用作质心，大小和定向的像素化来源（例如恒星和星系）。但是，在图像上进行的所有测量都遭受了由于不足采样和有限像素的大小而造成的错误，从而在矩和其他统计数据的计算中导致系统偏见。我们在第一个和第二几何矩中显示了偏差的示例，这些偏差是根据像素量表接近宽度的高斯源图像计算出的，$ 0.1 <σ<5 $像素。然后，我们说明了如何导致在天空的各种现代调查中看到的方向角度模式。
Spatial intensity moments computed on images can be used as a probe of the centroid, size, and orientation of pixelized sources such as stars and galaxies. However, all measurements made on images suffer from errors due to undersampling and finite pixel size, causing systematic biases in the computation of moments and other statistics. We show examples of bias in the first and second geometric moments computed on images of Gaussian sources with widths near the pixel scale, $0.1<σ<5$ pixels. We then illustrate how undersampling could lead to the orientation angle patterns seen in various modern surveys of the sky.
