Lake ice thickness is an important parameter for understanding hydrological changes and implications in the Northern Hemisphere, yet, observation frequency is limited by logistical challenges. Two mid-latitude freshwater lakes with floating ice cover in Haliburton, ON, have lake ice thickness observations varying from 35-70 cm between seasons over the past six years. The use of RADAR has emerged as a remote sensing solution for lake ice thickness estimates, to alleviate the logistical limitations of in-situ measurements. The University of Waterloo-designed airborne CryoSAR sensor has been in use over the study lakes during the 2022 and 2023 field season, and provides Ku and L-band backscatter information. Presently, scattering of Ku-band signals can not be fully explained by the known causes of scattering (primarily bubbles) within the ice column. The suspected cause of this additional scattering is roughness of the ice surface at the ice-water interface, which has yet to be measured in the field and is typically estimated. Using malleable clay to manually make impressions of the bottom of the ice, we have been able to measure the microtopography features at the ice-water interface and quantify the roughness of this surface. Measurements from the 2022 winter field season of the total imprint depth per unit area of the ice bottom surface in 2022 range from 0.198 mm/cm2 to 1.323 mm/cm2. Measurements are underway for the 2023 season, and using the known ice-water interface roughness, backscatter strength from Ku and L-band sensors will be used to estimate the lake ice thickness.