Continues as;
 
“Hence, in the red we only permitted backscattering peaks below 80 km and retained the fractal phase functions without backward peaks above. This proved sufficient to match the DLVS observations with azimuth. With these trial phase functions we found the profiles of extinction optical depth and single-scattering albedo with altitude necessary to match the ULVS and DLVS observations at the red and blue SA wavelengths.”
Isophotes has to be understood before looking at the figures 21 and others like this
In geometry, an isophote is a curve on an illuminated surface that connects points of equal brightness. One supposes that the illumination is done by parallel light and the brightness