SAR altimeter

Hi
On page 22 of the article http://www.satoc.eu/projects/CP4O/docs/SARALT_EG_pdfs/SAR%20Altimetry%20NOC%20Southampton%202013%20Phalippou.pdf and page 3 https://www.researchgate.net/publication/3761353_DelayDoppler_radar_altimeter_better_measurement_precision there are graphics. Where can I get numerical calculation on whose basis these graphics were calculated3?
Thank you