Left: example of an initial 1D profile for a simple crater and the least-squares fit to the background gradient. Center: crater depth and diameter are determined by dividing the profile into two halves at its deepest point and calculating the rim as the point in each half where the slope decreases to 10% of its maximum. Right: diameter is taken as the distance between the two rim points, and depth is the difference between the average rim height and the deepest point in the profile.