Delta-T Devices SunScan SS1 User Manual page 56

Accuracy of LAI calculations
When used to predict LAI from transmitted fraction, the functions used in
the SunData software are accurate to within ±10% ±0.1 over the range of
LAI less than 10 and Zenith Angle less than 60° when compared to the
output of the full model.
The errors become larger for highly vertical leaves with a strong low sun,
and users should avoid these conditions if possible.
In practice, the greatest errors are likely to follow from the differences
between the real canopy and the idealised assumptions in the model.
56  LAI theory
SS1 User Manual v3.3