A new Plant Facility in Wageningen

Date

Wednesday 7 September 2011

Venue

Wageningen Campus

Description

Recently, a laboratory measurement facility has been realized for assessing the anisotropic reflectance and emittance behaviour of soils, leaves and small canopies under controlled illumination conditions. These measurements can be used, e.g., to assess the plant pigment (chlorophyll, xanthophyll, etc.) and non-pigment system (water, cellulose, lignin, nitrogen, etc.).

The facility consists of an ASD FieldSpec spectroradiometer covering the spectral range from 350 – 2500 nm at 1 nm spectral sampling interval. The thermal emittance is measured using a NEC TH9100 Infrared Thermal Imager. It operates in a single band covering the spectral range from 8 – 14 mm with a resolution of 0.02 K. A 1000 W Quartz Tungsten Halogen lamp is used as illumination source, approximating the radiance distribution of the sun. In the near future a pulsed LED illumination system will be added in order to perform measurements on induced chlorophyll fluorescence of photosystem PSII.

Multi-angular measurements are achieved by using a robotic positioning system allowing to perform either reflectance or emittance measurements over almost a complete hemisphere. The hemisphere can be sampled continuously between 0° and 80° from nadir and up to a few degrees from the hot-spot configuration. The goal is to infer the BRDF (bidirectional reflectance distribution function) and BTDF (bidirectional thermal distribution function) from these multi-angular measurements for various surface types (like soils, agricultural crops, small tree canopies and artificial objects) and surface roughness. The steering of the robotic arm and the reading of the spectroradiometer and the thermal camera are all fully automated.

Demonstrations:

1) Plant Facility
2) XY Phenotyping system
3) Terrestrial Laser system