Step 3. Let Y = X be any other target listed in Table 1. When applying GLK to the **data** F Y (t), use the same calibration factor CF (X) . Here CF (wood stake) = 10 −5 , R GLK = 3.8; b) the function R GLK (plastic cylinder) for the case when the plastic cylinder was the calibration target. Here CF (plastic cylinder) = 1.8 · 10 −5 , R GLK (plastic cylinder) = 0.28; c) the function R GLK (bush) for the case when bush was the calibration target. Here CF (bush) = 0.6 · 10 −5 , R GLK (bush) = 6.4.