Actual surface coverage for each profile varies widely.
Solid lines are best fits to data points.
If we assume the mean dielectric constant of these lavas is 5, then we can calculate the shift in echo power due to changes in the dielectric constant. Dotted lines show the modified best-fit line for dielectric values of 10 and 3. Data from other sources show 24-cm HH and HV echoes for these flows remain nearly constant for rms heights greater than 10 cm. Incidence angles are marked along left side of each image. Compare this with the high degree of unit discrimination possible at all angles with the HV images.