Fig. 6: Demonstration of calibration of spatial scaling factor.
From: Nano-precision metrology of X-ray mirrors with laser speckle angular measurement
a Schematic representation of the scaling calibration, performed by choosing multiple subset windows at different vertical positions on the camera from a stack of speckle images. b The tangential mirror slope profile of the elliptical mirror after subtraction of the best-fit ellipse. c The zoomed region of (b), showing how the slope error profile shifts with the subset window. d The line fitting between the tracked position shift on the mirror and the subset window shift on the camera
