Comparison between the measured (solid lines) and fitted profiles (dashed lines) for three pixels, each representing varying degrees of accuracy (top panel). The FTS is shown as a reference. The bottom panel displays the distribution of χ² values for all pixels. Among the three selected cases, one demonstrates an average fit (depicted in pink, with χ² close to the mean value), while the other two correspond with extreme cases—one with a notably good fit and the other with a poor fit (depicted in yellow and blue, respectively). The value for χ² has been computed employing Eq. (12).