Height of the granulation contrast inversion layer derived from a cross-correlation method

Using spectroscopic data from Hinode/SOT we have obtained monochromatic images of the solar granulation at different levels in the Fe i 603 nm lines. The granulation contrast inversion is clearly detected as a negative peak in the cross-correlation of images at the continuum level and at line center levels. Taking advantage of the perspective effect which appears in images taken out of the solar disk center, we were able to measure the formation heights of the lines and the height of the contrast inversion layer.