suggesting the absence of deformation of the interacting tip and

To the best of our knowledge no reports on error in BTR measurements have been presented in the literature. Therefore, it was decided that using the certainty map was the best method to quantify the error associated with BTR measurements since multiple images with the same or nearly the same amount of noise gave the exact same radius of curvature. The certainty map reports the percent of pixels that contain noise, and this percent is taken as the percent error in the tip radius of curvature determination.