Residuals of linearised ramp after subtracting a linear fit. The X-offset is with respect to the brightest central pixel trace, while the Y-coordinates are a range. The x-axes are the observed DN of the original ramp, divided by the maximum DN-value reached. The colour map shows the DN-level of the specific time-sample indicated by the dot, where 55 000 DN roughly corresponds to the imposed saturation limit (55 030 DN). The residuals show a systematic sinusoid signature with DN-level reached, around a noise floor of approximately 50 DN.