Wheat leaf bidirectional reflectance measurements: Description and quantification of the volume, specular and hot-spot scattering features

► Wheat leaf bidirectional reflectance was measured with a conoscope. ► DHRF was computed from the BRF measurements. ► The contribution of scattering processes such as hotspot on the BRDF was estimated. ► An oriented roughness corresponding to the longitudinal veins of wheat leaves was observed. ► The volume scattering was tentatively estimated from the BRDF.