We are presenting an atmospheric modelling and inversion model for the FINCH (Field Imaging Nanosatellite for Crop residue Hyperspectral mapping) pushbroom hyperspectral imaging CubeSat, built by the University of Toronto Aerospace Team Space Systems division. Such a model will allow us to validate our spectral unmixing pipeline under possible FINCH imaging conditions, as well as finalise and validate the atmospheric inversion pipeline for FINCH-sourced data, thus permitting scientifically useful data collection. FINCH, through innovations in crop residue cover mapping, will further enable sustainable agricultural practices, and serve as a template for other low cost, mission focused, scientificality useful remote sensing missions. We have accounted for all significant aspects that impact our capability to map crop residue cover, and we have developed a process to simulate data for training and validation.