Phase: RAMI3Absorption by the canopy (turbid or discrete)
fabs for HET01_DIS_UNI_RED_20 testcase.
fabs for HET01_DIS_UNI_RED_50 testcase.
fabs for HET01_DIS_UNI_NIR_20 testcase.
fabs for HET01_DIS_UNI_NIR_50 testcase.