Validation of neural net techniques to estimate canopy biophysical variables from remote sensing data Marie Weiss, Frédéric Baret, Marc Leroy, Olivier Hautecœur, Cédric Bacour, Laurent Prévot and Nadine Bruguier Agronomie, 22 6 (2002) 547-553 DOI: 10.1051/agro:2002036