Comparison of cumulative trap density (cnt) at the top of the CCD for all species from two sources: the simulation ground truth (in blue) and the fitted polynomial model (in dashed red). The plot highlights certain species-specific behaviour, with Species 2 exhibiting a systematic offset. Note that Species 1 is poorly constrained because its release time is significantly shorter than the line transfer time; however, as detailed in Sect. 2.5, this species contributes negligibly to the total CTI-induced bias.